Agatino Battaglia - Academia.edu (original) (raw)

Papers by Agatino Battaglia

Research paper thumbnail of Mitochondrial myopathy" ormitochondrial disease? EEG,ERG,VEPstudies in13children

Neurophysiological investigations (EEG, ERG, VEP) were carried out in 13 patients with proven "mi... more Neurophysiological investigations (EEG, ERG, VEP) were carried out in 13 patients with proven "mitochondrial myopathy". There were nine girls and four boys. Varied abnormalities were seen in the EEGs of all cases, and in one patient unusual repetitive bursts of irregular slow waves and spikes were observed. The ERG was abnormal in five of the 12 cases tested, while the VEP (flash) was definitely abnormal in six out of these 12 cases. These neurophysiological findings suggest some involvement of both the brain and the visual system. It seem therefore appropriate that this condition be considered a "mitochondrial disease" affecting many systems rather than only muscles.

Research paper thumbnail of MET and autism susceptibility: family and case–control studies

European Journal of Human Genetics, Nov 12, 2008

Autism is a common, severe and highly heritable neurodevelopmental disorder. The International Mo... more Autism is a common, severe and highly heritable neurodevelopmental disorder. The International Molecular Genetic Study of Autism Consortium (IMGSAC) genome screen for linkage in affected sib-pair families identified a chromosome 7q susceptibility locus (AUTS1), that has subsequently shown evidence of increased sharing in several independent multiplex samples and in two meta-analyses. Taking into account the location of the MET gene under this linkage peak, and the fact that it has recently been reported to be associated with autism, the gene was further analyzed as a promising autism candidate. The gene encodes a transmembrane receptor tyrosine kinase of the hepatocyte growth factor/scatter factor (HGF/SF). MET is best known as an oncogene, but its signalling also participates in immune function, peripheral organ development and repair, and the development of the cerebral cortex and cerebellum (all of which have been observed earlier as being disregulated in individuals with autism). Here we present a family-based association analysis covering the entire MET locus. Significant results were obtained in both single locus and haplotype approaches with a single nucleotide polymorphism in intron 1 (rs38845, Po0.004) and with one intronic haplotype (AAGTG, Po0.009) in 325 multiplex IMGSAC families and 10 IMGSAC trios. Although these results failed to replicate in an independent sample of 82 Italian trios, the association itself was confirmed by a case-control analysis performed using the Italian cohort (Po0.02). The previously reported positive association of rs1858830 failed to replicate in this study. Overall, our findings provide further evidence that MET may play a role in autism susceptibility.

Research paper thumbnail of Dissecting the multifaceted contribution of the mitochondrial genome to autism spectrum disorder

Frontiers in Genetics

Autism spectrum disorder (ASD) is a clinically heterogeneous class of neurodevelopmental conditio... more Autism spectrum disorder (ASD) is a clinically heterogeneous class of neurodevelopmental conditions with a strong, albeit complex, genetic basis. The genetic architecture of ASD includes different genetic models, from monogenic transmission at one end, to polygenic risk given by thousands of common variants with small effects at the other end. The mitochondrial DNA (mtDNA) was also proposed as a genetic modifier for ASD, mostly focusing on maternal mtDNA, since the paternal mitogenome is not transmitted to offspring. We extensively studied the potential contribution of mtDNA in ASD pathogenesis and risk through deep next generation sequencing and quantitative PCR in a cohort of 98 families. While the maternally-inherited mtDNA did not seem to predispose to ASD, neither for haplogroups nor for the presence of pathogenic mutations, an unexpected influence of paternal mtDNA, apparently centered on haplogroup U, came from the Italian families extrapolated from the test cohort (n = 74) w...

Research paper thumbnail of Further Delineation of Deletion 1p36 Syndrome in 60 Patients: A Recognizable Phenotype and Common Cause of Developmental Delay and Mental Retardation

Pediatrics, 2008

OBJECTIVES. Deletion 1p36 syndrome is a recently delineated disorder, considered to be the most c... more OBJECTIVES. Deletion 1p36 syndrome is a recently delineated disorder, considered to be the most common subtelomeric microdeletion syndrome (1 in 5000 newborns). 1p36.3 deletions account for 0.5% to 1.2% of idiopathic mental retardation; thus, knowledge about the condition is important for pediatricians caring for such patients. Despite 100 reported cases, little is known about its natural history. Our aim was to delineate the natural history of deletion 1p36 and develop complete and accurate information with which to answer families' questions in the clinical setting. PATIENTS AND METHODS. We evaluated 60 patients with the 1p36 deletion syndrome (41 female, 19 male). All underwent physical and neurologic assessments, and most received a psychological evaluation. Standard cytogenetics, fluorescence in situ hybridization of the subtelomeric regions, or array comparative genomic hybridization were used for diagnosis. RESULTS. Fourteen cases were detected by standard cytogenetics, a...

Research paper thumbnail of Periventricular heterotopia in fragile X syndrome

Neurology, 2006

The authors describe two unrelated individuals with fragile X syndrome (FXS) due to marked expans... more The authors describe two unrelated individuals with fragile X syndrome (FXS) due to marked expansion and instability of the CGG trinucleotide repeats within the fragile X mental retardation 1 gene (FMR1) and periventricular heterotopia (PH). This observation suggests that the FMR1 gene is involved in neuronal migration and that abnormal neuronal migration, even beyond the resolution of MRI, contributes to the neurologic phenotype of FXS.

Research paper thumbnail of Adrenoleucodystrophy: neurophysiological aspects

Journal of Neurology, Neurosurgery & Psychiatry, 1981

Neurophysiological investigations (EEG, ERG, VEP) were carried out in 14 boys with adrenoleucodys... more Neurophysiological investigations (EEG, ERG, VEP) were carried out in 14 boys with adrenoleucodystrophy, and in two siblings with adrenocortical deficiency, but without neurological symptoms. Irregular large amplitude (200-800 microvolts) slow activity was found in the EEG of all adrenoleucodystrophy patients, usually more prominent over the posterior regions of the brain. No short duration spikes or complex wave forms were seen in any of the EEGs, even in those patients who had had seizures. Clinical deterioration was not always accompanied by an increase in EEG abnormalities. The ERG was of usual amplitude and wave form, while the VEP (flash) was altered in four cases. The two clinically unaffected siblings had normal ERG/VEP, and only a modest excess of slow waves in the EEG. The neurophysiological findings in adrenoleucodystrophy are not seen in other diseases with similar clinical symptoms in the same age group.

Research paper thumbnail of Mitochondrial myopathy" or mitochondrial disease? EEG, ERG, VEP studies in 13 children

Journal of Neurology, Neurosurgery & Psychiatry, 1982

Neurophysiological investigations (EEG, ERG, VEP) were carried out in 13 patients with proven "mi... more Neurophysiological investigations (EEG, ERG, VEP) were carried out in 13 patients with proven "mitochondrial myopathy". There were nine girls and four boys. Varied abnormalities were seen in the EEGs of all cases, and in one patient unusual repetitive bursts of irregular slow waves and spikes were observed. The ERG was abnormal in five of the 12 cases tested, while the VEP (flash) was definitely abnormal in six out of these 12 cases. These neurophysiological findings suggest some involvement of both the brain and the visual system. It seem therefore appropriate that this condition be considered a "mitochondrial disease" affecting many systems rather than only muscles.

Research paper thumbnail of A novel approach of homozygous haplotype sharing identifies candidate genes in autism spectrum disorder

Human genetics, 2012

Autism spectrum disorder (ASD) is a highly heritable disorder of complex and heterogeneous aetiol... more Autism spectrum disorder (ASD) is a highly heritable disorder of complex and heterogeneous aetiology. It is primarily characterized by altered cognitive ability including impaired language and communication skills and fundamental deficits in social reciprocity. Despite some notable successes in neuropsychiatric genetics, overall, the high heritability of ASD (~90%) remains poorly explained by common genetic risk variants. However, recent studies suggest that rare genomic variation, in particular copy number variation, may account for a significant proportion of the genetic basis of ASD. We present a large scale analysis to identify candidate genes which may contain low-frequency recessive variation contributing to ASD while taking into account the potential contribution of population differences to the genetic heterogeneity of ASD. Our strategy, homozygous haplotype (HH) mapping, aims to detect homozygous segments of identical haplotype structure that are shared at a higher frequenc...

Research paper thumbnail of Meta-analysis of GWAS of over 16,000 individuals with autism spectrum disorder highlights a novel locus at 10q24.32 and a significant overlap with schizophrenia

Molecular Autism, 2017

Background: Over the past decade genome-wide association studies (GWAS) have been applied to aid ... more Background: Over the past decade genome-wide association studies (GWAS) have been applied to aid in the understanding of the biology of traits. The success of this approach is governed by the underlying effect sizes carried by the true risk variants and the corresponding statistical power to observe such effects given the study design and sample size under investigation. Previous ASD GWAS have identified genome-wide significant (GWS) risk loci; however, these studies were of only of low statistical power to identify GWS loci at the lower effect sizes (odds ratio (OR) <1.15). Methods: We conducted a large-scale coordinated international collaboration to combine independent genotyping data to improve the statistical power and aid in robust discovery of GWS loci. This study uses genome-wide genotyping data from a discovery sample (7387 ASD cases and 8567 controls) followed by meta-analysis of summary statistics from two replication sets (7783 ASD cases and 11359 controls; and 1369 ASD cases and 137308 controls). Results: We observe a GWS locus at 10q24.32 that overlaps several genes including PITX3, which encodes a transcription factor identified as playing a role in neuronal differentiation and CUEDC2 previously reported to be associated with social skills in an independent population cohort. We also observe overlap with regions previously implicated in schizophrenia which was further supported by a strong genetic correlation between these disorders (Rg = 0.23; P = 9 × 10 −6). We further combined these Psychiatric Genomics Consortium (PGC) ASD GWAS data with the recent PGC schizophrenia GWAS to identify additional regions which may be important in a common neurodevelopmental phenotype and identified 12 novel GWS loci. These include loci previously implicated in ASD such as FOXP1 at 3p13, ATP2B2 at 3p25.3, and a 'neurodevelopmental hub' on chromosome 8p11.23. Conclusions: This study is an important step in the ongoing endeavour to identify the loci which underpin the common variant signal in ASD. In addition to novel GWS loci, we have identified a significant genetic correlation with schizophrenia and association of ASD with several neurodevelopmental-related genes such as EXT1, ASTN2, MACROD2, and HDAC4.

Research paper thumbnail of An integrated analysis of rare CNV and exome variation in Autism Spectrum Disorder using the Infinium PsychArray

Scientific Reports, 2020

Autism spectrum disorder (ASD) is a neurodevelopmental condition with a complex and heterogeneous... more Autism spectrum disorder (ASD) is a neurodevelopmental condition with a complex and heterogeneous genetic etiology. While a proportion of ASD risk is attributable to common variants, rare copy-number variants (CNVs) and protein-disrupting single-nucleotide variants (SNVs) have been shown to significantly contribute to ASD etiology. We analyzed a homogeneous cohort of 127 ASD Italian families genotyped with the Illumina PsychArray, to perform an integrated analysis of CNVs and SNVs and to assess their contribution to ASD risk. We observed a higher burden of rare CNVs, especially deletions, in ASD individuals versus unaffected controls. Furthermore, we identified a significant enrichment of rare CNVs intersecting ASD candidate genes reported in the SFARI database. Family-based analysis of rare SNVs genotyped by the PsychArray also indicated an increased transmission of rare SNV variants from heterozygous parents to probands, supporting a multigenic model of ASD risk with significant c...

Research paper thumbnail of Episignatures stratifying ADNP syndrome show modest correlation with phenotype

ADNP syndrome, also known as Helsmoortel-van Der Aa syndrome, is a neurodevelopmental condition a... more ADNP syndrome, also known as Helsmoortel-van Der Aa syndrome, is a neurodevelopmental condition associated with intellectual disability/developmental delay, autism spectrum disorder, and multiple medical comorbidities. ADNP syndrome is caused by mutations in the activity-dependent neuroprotective protein (ADNP). A recent study identified genome-wide DNA methylation changes in 22 individuals with ADNP syndrome, adding to the group of neurodevelopmental disorders with an epigenetic signature. This methylation signature segregated those with ADNP syndrome into two groups, based on the location of the mutations. Here, we conducted an independent study on 24 individuals with ADNP syndrome and replicated the existence of the two, mutation-dependent ADNP episignatures. To probe whether the two distinct episignatures correlate with clinical outcomes, we used deep behavioral and neurobiological data from two prospective cohorts of individuals with a genetic diagnosis of ADNP syndrome. We fou...

Research paper thumbnail of Polygenic transmission disequilibrium confirms that common and rare variation act additively to create risk for autism spectrum disorders

Nature genetics, Jan 15, 2017

Autism spectrum disorder (ASD) risk is influenced by common polygenic and de novo variation. We a... more Autism spectrum disorder (ASD) risk is influenced by common polygenic and de novo variation. We aimed to clarify the influence of polygenic risk for ASD and to identify subgroups of ASD cases, including those with strongly acting de novo variants, in which polygenic risk is relevant. Using a novel approach called the polygenic transmission disequilibrium test and data from 6,454 families with a child with ASD, we show that polygenic risk for ASD, schizophrenia, and greater educational attainment is over-transmitted to children with ASD. These findings hold independent of proband IQ. We find that polygenic variation contributes additively to risk in ASD cases who carry a strongly acting de novo variant. Lastly, we show that elements of polygenic risk are independent and differ in their relationship with phenotype. These results confirm that the genetic influences on ASD are additive and suggest that they create risk through at least partially distinct etiologic pathways.

Research paper thumbnail of Gene-ontology enrichment analysis in two independent family-based samples highlights biologically plausible processes for autism spectrum disorders

European Journal of Human Genetics, 2011

Recent genome-wide association studies (GWAS) have implicated a range of genes from discrete biol... more Recent genome-wide association studies (GWAS) have implicated a range of genes from discrete biological pathways in the aetiology of autism. However, despite the strong influence of genetic factors, association studies have yet to identify statistically robust, replicated major effect genes or SNPs. We apply the principle of the SNP ratio test methodology described by O'Dushlaine et al to over 2100 families from the Autism Genome Project (AGP). Using a two-stage design we examine association enrichment in 5955 unique gene-ontology classifications across four groupings based on two phenotypic and two ancestral classifications. Based on estimates from simulation we identify excess of association enrichment across all analyses. We observe enrichment in association for sets of genes involved in diverse biological processes, including pyruvate metabolism, transcription factor activation, cell-signalling and cell-cycle regulation. Both genes and processes that show enrichment have previously been examined in autistic disorders and offer biologically plausibility to these findings.

Research paper thumbnail of Mutation screening and association analysis of six candidate genes for autism on chromosome 7q

European Journal of Human Genetics, 2004

Genetic studies have provided evidence for an autism susceptibility locus (AUTS1) on chromosome 7... more Genetic studies have provided evidence for an autism susceptibility locus (AUTS1) on chromosome 7q. Screening for mutations in six genes mapping to 7q, CUTL1, SRPK2, SYPL, LAMB1, NRCAM and PTPRZ1 in 48 unrelated individuals with autism led to the identification of several new coding variants in the genes CUTL1, LAMB1 and PTPRZ1. Analysis of genetic variants provided evidence for association with autism for one of the new missense changes identified in LAMB1; this effect was stronger in a subgroup of affected male sibling pair families, implying a possible specific sex-related effect for this variant. Association was also detected for several polymorphisms in the promoter and untranslated region of NRCAM, suggesting that alterations in expression of this gene may be linked to autism susceptibility.

Research paper thumbnail of Functional impact of global rare copy number variation in autism spectrum disorders

Nature, Jan 15, 2010

The autism spectrum disorders (ASDs) are a group of conditions characterized by impairments in re... more The autism spectrum disorders (ASDs) are a group of conditions characterized by impairments in reciprocal social interaction and communication, and the presence of restricted and repetitive behaviours. Individuals with an ASD vary greatly in cognitive development, which can range from above average to intellectual disability. Although ASDs are known to be highly heritable ( approximately 90%), the underlying genetic determinants are still largely unknown. Here we analysed the genome-wide characteristics of rare…

Research paper thumbnail of Further Delineation of Deletion lp36 Syndrome in 60 Patients : A Recognizable Phenotype and Common Cause of Developmental Delay and Mental Retardation

Research paper thumbnail of Perinatal distress in 1p36 deletion syndrome can mimic hypoxic ischemic encephalopathy

American Journal of Medical Genetics Part A

Research paper thumbnail of Risk of hepatic neoplasms in Wolf-Hirschhorn syndrome (4p-): Four new cases and review of the literature

American journal of medical genetics. Part A, Jan 5, 2018

Wolf-Hirschhorn syndrome (WHS) is a rare contiguous gene deletion disorder characterized by disti... more Wolf-Hirschhorn syndrome (WHS) is a rare contiguous gene deletion disorder characterized by distinctive craniofacial features, prenatal/postnatal growth deficiency, intellectual disability, and seizures. Various malformations of internal organs are also seen. Neoplasia has not been documented as a typical feature of WHS. We review the three prior reports of hepatic neoplasia in WHS and add four previously unreported individuals. We propose that, in the context of the rarity of WHS, these seven cases suggest that hepatocellular neoplasia may be a feature of WHS.

Research paper thumbnail of De Novo Variants in the F-Box Protein FBXO11 in 20 Individuals with a Variable Neurodevelopmental Disorder

American journal of human genetics, Jan 2, 2018

Next-generation sequencing combined with international data sharing has enormously facilitated id... more Next-generation sequencing combined with international data sharing has enormously facilitated identification of new disease-associated genes and mutations. This is particularly true for genetically extremely heterogeneous entities such as neurodevelopmental disorders (NDDs). Through exome sequencing and world-wide collaborations, we identified and assembled 20 individuals with de novo variants in FBXO11. They present with mild to severe developmental delay associated with a range of features including short (4/20) or tall (2/20) stature, obesity (5/20), microcephaly (4/19) or macrocephaly (2/19), behavioral problems (17/20), seizures (5/20), cleft lip or palate or bifid uvula (3/20), and minor skeletal anomalies. FBXO11 encodes a member of the F-Box protein family, constituting a subunit of an E3-ubiquitin ligase complex. This complex is involved in ubiquitination and proteasomal degradation and thus in controlling critical biological processes by regulating protein turnover. The i...

Research paper thumbnail of A survey of antiepileptic drug responses identifies drugs with potential efficacy for seizure control in Wolf-Hirschhorn syndrome

Epilepsy & behavior : E&B, Jan 22, 2018

Seizures are present in over 90% of infants and children with Wolf-Hirschhorn syndrome (WHS). Whe... more Seizures are present in over 90% of infants and children with Wolf-Hirschhorn syndrome (WHS). When present, they significantly affect quality of life. The goal of this study was to use caregiver reports to describe the comparative efficacies of commonly used antiepileptic medications in a large population of individuals with WHS. A web-based, confidential caregiver survey was developed to capture seizure semiology and a chronologic record of seizure treatments as well as responses to each treatment. Adverse events for each drug were also cataloged. We received 141 complete survey responses (47% response rate) describing the seizures of individuals ranging in age from 4months to 61years (90 females: 51 males). Using the Early Childhood Epilepsy Severity Scale (E-Chess), WHS-associated seizures are demonstrably severe regardless of deletion size. The best-performing antiepileptic drugs (AEDs) for controlling seizures in this cohort were broad spectrum drugs clobazam, levetiracetam, an...

Research paper thumbnail of Mitochondrial myopathy" ormitochondrial disease? EEG,ERG,VEPstudies in13children

Neurophysiological investigations (EEG, ERG, VEP) were carried out in 13 patients with proven "mi... more Neurophysiological investigations (EEG, ERG, VEP) were carried out in 13 patients with proven "mitochondrial myopathy". There were nine girls and four boys. Varied abnormalities were seen in the EEGs of all cases, and in one patient unusual repetitive bursts of irregular slow waves and spikes were observed. The ERG was abnormal in five of the 12 cases tested, while the VEP (flash) was definitely abnormal in six out of these 12 cases. These neurophysiological findings suggest some involvement of both the brain and the visual system. It seem therefore appropriate that this condition be considered a "mitochondrial disease" affecting many systems rather than only muscles.

Research paper thumbnail of MET and autism susceptibility: family and case–control studies

European Journal of Human Genetics, Nov 12, 2008

Autism is a common, severe and highly heritable neurodevelopmental disorder. The International Mo... more Autism is a common, severe and highly heritable neurodevelopmental disorder. The International Molecular Genetic Study of Autism Consortium (IMGSAC) genome screen for linkage in affected sib-pair families identified a chromosome 7q susceptibility locus (AUTS1), that has subsequently shown evidence of increased sharing in several independent multiplex samples and in two meta-analyses. Taking into account the location of the MET gene under this linkage peak, and the fact that it has recently been reported to be associated with autism, the gene was further analyzed as a promising autism candidate. The gene encodes a transmembrane receptor tyrosine kinase of the hepatocyte growth factor/scatter factor (HGF/SF). MET is best known as an oncogene, but its signalling also participates in immune function, peripheral organ development and repair, and the development of the cerebral cortex and cerebellum (all of which have been observed earlier as being disregulated in individuals with autism). Here we present a family-based association analysis covering the entire MET locus. Significant results were obtained in both single locus and haplotype approaches with a single nucleotide polymorphism in intron 1 (rs38845, Po0.004) and with one intronic haplotype (AAGTG, Po0.009) in 325 multiplex IMGSAC families and 10 IMGSAC trios. Although these results failed to replicate in an independent sample of 82 Italian trios, the association itself was confirmed by a case-control analysis performed using the Italian cohort (Po0.02). The previously reported positive association of rs1858830 failed to replicate in this study. Overall, our findings provide further evidence that MET may play a role in autism susceptibility.

Research paper thumbnail of Dissecting the multifaceted contribution of the mitochondrial genome to autism spectrum disorder

Frontiers in Genetics

Autism spectrum disorder (ASD) is a clinically heterogeneous class of neurodevelopmental conditio... more Autism spectrum disorder (ASD) is a clinically heterogeneous class of neurodevelopmental conditions with a strong, albeit complex, genetic basis. The genetic architecture of ASD includes different genetic models, from monogenic transmission at one end, to polygenic risk given by thousands of common variants with small effects at the other end. The mitochondrial DNA (mtDNA) was also proposed as a genetic modifier for ASD, mostly focusing on maternal mtDNA, since the paternal mitogenome is not transmitted to offspring. We extensively studied the potential contribution of mtDNA in ASD pathogenesis and risk through deep next generation sequencing and quantitative PCR in a cohort of 98 families. While the maternally-inherited mtDNA did not seem to predispose to ASD, neither for haplogroups nor for the presence of pathogenic mutations, an unexpected influence of paternal mtDNA, apparently centered on haplogroup U, came from the Italian families extrapolated from the test cohort (n = 74) w...

Research paper thumbnail of Further Delineation of Deletion 1p36 Syndrome in 60 Patients: A Recognizable Phenotype and Common Cause of Developmental Delay and Mental Retardation

Pediatrics, 2008

OBJECTIVES. Deletion 1p36 syndrome is a recently delineated disorder, considered to be the most c... more OBJECTIVES. Deletion 1p36 syndrome is a recently delineated disorder, considered to be the most common subtelomeric microdeletion syndrome (1 in 5000 newborns). 1p36.3 deletions account for 0.5% to 1.2% of idiopathic mental retardation; thus, knowledge about the condition is important for pediatricians caring for such patients. Despite 100 reported cases, little is known about its natural history. Our aim was to delineate the natural history of deletion 1p36 and develop complete and accurate information with which to answer families' questions in the clinical setting. PATIENTS AND METHODS. We evaluated 60 patients with the 1p36 deletion syndrome (41 female, 19 male). All underwent physical and neurologic assessments, and most received a psychological evaluation. Standard cytogenetics, fluorescence in situ hybridization of the subtelomeric regions, or array comparative genomic hybridization were used for diagnosis. RESULTS. Fourteen cases were detected by standard cytogenetics, a...

Research paper thumbnail of Periventricular heterotopia in fragile X syndrome

Neurology, 2006

The authors describe two unrelated individuals with fragile X syndrome (FXS) due to marked expans... more The authors describe two unrelated individuals with fragile X syndrome (FXS) due to marked expansion and instability of the CGG trinucleotide repeats within the fragile X mental retardation 1 gene (FMR1) and periventricular heterotopia (PH). This observation suggests that the FMR1 gene is involved in neuronal migration and that abnormal neuronal migration, even beyond the resolution of MRI, contributes to the neurologic phenotype of FXS.

Research paper thumbnail of Adrenoleucodystrophy: neurophysiological aspects

Journal of Neurology, Neurosurgery & Psychiatry, 1981

Neurophysiological investigations (EEG, ERG, VEP) were carried out in 14 boys with adrenoleucodys... more Neurophysiological investigations (EEG, ERG, VEP) were carried out in 14 boys with adrenoleucodystrophy, and in two siblings with adrenocortical deficiency, but without neurological symptoms. Irregular large amplitude (200-800 microvolts) slow activity was found in the EEG of all adrenoleucodystrophy patients, usually more prominent over the posterior regions of the brain. No short duration spikes or complex wave forms were seen in any of the EEGs, even in those patients who had had seizures. Clinical deterioration was not always accompanied by an increase in EEG abnormalities. The ERG was of usual amplitude and wave form, while the VEP (flash) was altered in four cases. The two clinically unaffected siblings had normal ERG/VEP, and only a modest excess of slow waves in the EEG. The neurophysiological findings in adrenoleucodystrophy are not seen in other diseases with similar clinical symptoms in the same age group.

Research paper thumbnail of Mitochondrial myopathy" or mitochondrial disease? EEG, ERG, VEP studies in 13 children

Journal of Neurology, Neurosurgery & Psychiatry, 1982

Neurophysiological investigations (EEG, ERG, VEP) were carried out in 13 patients with proven "mi... more Neurophysiological investigations (EEG, ERG, VEP) were carried out in 13 patients with proven "mitochondrial myopathy". There were nine girls and four boys. Varied abnormalities were seen in the EEGs of all cases, and in one patient unusual repetitive bursts of irregular slow waves and spikes were observed. The ERG was abnormal in five of the 12 cases tested, while the VEP (flash) was definitely abnormal in six out of these 12 cases. These neurophysiological findings suggest some involvement of both the brain and the visual system. It seem therefore appropriate that this condition be considered a "mitochondrial disease" affecting many systems rather than only muscles.

Research paper thumbnail of A novel approach of homozygous haplotype sharing identifies candidate genes in autism spectrum disorder

Human genetics, 2012

Autism spectrum disorder (ASD) is a highly heritable disorder of complex and heterogeneous aetiol... more Autism spectrum disorder (ASD) is a highly heritable disorder of complex and heterogeneous aetiology. It is primarily characterized by altered cognitive ability including impaired language and communication skills and fundamental deficits in social reciprocity. Despite some notable successes in neuropsychiatric genetics, overall, the high heritability of ASD (~90%) remains poorly explained by common genetic risk variants. However, recent studies suggest that rare genomic variation, in particular copy number variation, may account for a significant proportion of the genetic basis of ASD. We present a large scale analysis to identify candidate genes which may contain low-frequency recessive variation contributing to ASD while taking into account the potential contribution of population differences to the genetic heterogeneity of ASD. Our strategy, homozygous haplotype (HH) mapping, aims to detect homozygous segments of identical haplotype structure that are shared at a higher frequenc...

Research paper thumbnail of Meta-analysis of GWAS of over 16,000 individuals with autism spectrum disorder highlights a novel locus at 10q24.32 and a significant overlap with schizophrenia

Molecular Autism, 2017

Background: Over the past decade genome-wide association studies (GWAS) have been applied to aid ... more Background: Over the past decade genome-wide association studies (GWAS) have been applied to aid in the understanding of the biology of traits. The success of this approach is governed by the underlying effect sizes carried by the true risk variants and the corresponding statistical power to observe such effects given the study design and sample size under investigation. Previous ASD GWAS have identified genome-wide significant (GWS) risk loci; however, these studies were of only of low statistical power to identify GWS loci at the lower effect sizes (odds ratio (OR) <1.15). Methods: We conducted a large-scale coordinated international collaboration to combine independent genotyping data to improve the statistical power and aid in robust discovery of GWS loci. This study uses genome-wide genotyping data from a discovery sample (7387 ASD cases and 8567 controls) followed by meta-analysis of summary statistics from two replication sets (7783 ASD cases and 11359 controls; and 1369 ASD cases and 137308 controls). Results: We observe a GWS locus at 10q24.32 that overlaps several genes including PITX3, which encodes a transcription factor identified as playing a role in neuronal differentiation and CUEDC2 previously reported to be associated with social skills in an independent population cohort. We also observe overlap with regions previously implicated in schizophrenia which was further supported by a strong genetic correlation between these disorders (Rg = 0.23; P = 9 × 10 −6). We further combined these Psychiatric Genomics Consortium (PGC) ASD GWAS data with the recent PGC schizophrenia GWAS to identify additional regions which may be important in a common neurodevelopmental phenotype and identified 12 novel GWS loci. These include loci previously implicated in ASD such as FOXP1 at 3p13, ATP2B2 at 3p25.3, and a 'neurodevelopmental hub' on chromosome 8p11.23. Conclusions: This study is an important step in the ongoing endeavour to identify the loci which underpin the common variant signal in ASD. In addition to novel GWS loci, we have identified a significant genetic correlation with schizophrenia and association of ASD with several neurodevelopmental-related genes such as EXT1, ASTN2, MACROD2, and HDAC4.

Research paper thumbnail of An integrated analysis of rare CNV and exome variation in Autism Spectrum Disorder using the Infinium PsychArray

Scientific Reports, 2020

Autism spectrum disorder (ASD) is a neurodevelopmental condition with a complex and heterogeneous... more Autism spectrum disorder (ASD) is a neurodevelopmental condition with a complex and heterogeneous genetic etiology. While a proportion of ASD risk is attributable to common variants, rare copy-number variants (CNVs) and protein-disrupting single-nucleotide variants (SNVs) have been shown to significantly contribute to ASD etiology. We analyzed a homogeneous cohort of 127 ASD Italian families genotyped with the Illumina PsychArray, to perform an integrated analysis of CNVs and SNVs and to assess their contribution to ASD risk. We observed a higher burden of rare CNVs, especially deletions, in ASD individuals versus unaffected controls. Furthermore, we identified a significant enrichment of rare CNVs intersecting ASD candidate genes reported in the SFARI database. Family-based analysis of rare SNVs genotyped by the PsychArray also indicated an increased transmission of rare SNV variants from heterozygous parents to probands, supporting a multigenic model of ASD risk with significant c...

Research paper thumbnail of Episignatures stratifying ADNP syndrome show modest correlation with phenotype

ADNP syndrome, also known as Helsmoortel-van Der Aa syndrome, is a neurodevelopmental condition a... more ADNP syndrome, also known as Helsmoortel-van Der Aa syndrome, is a neurodevelopmental condition associated with intellectual disability/developmental delay, autism spectrum disorder, and multiple medical comorbidities. ADNP syndrome is caused by mutations in the activity-dependent neuroprotective protein (ADNP). A recent study identified genome-wide DNA methylation changes in 22 individuals with ADNP syndrome, adding to the group of neurodevelopmental disorders with an epigenetic signature. This methylation signature segregated those with ADNP syndrome into two groups, based on the location of the mutations. Here, we conducted an independent study on 24 individuals with ADNP syndrome and replicated the existence of the two, mutation-dependent ADNP episignatures. To probe whether the two distinct episignatures correlate with clinical outcomes, we used deep behavioral and neurobiological data from two prospective cohorts of individuals with a genetic diagnosis of ADNP syndrome. We fou...

Research paper thumbnail of Polygenic transmission disequilibrium confirms that common and rare variation act additively to create risk for autism spectrum disorders

Nature genetics, Jan 15, 2017

Autism spectrum disorder (ASD) risk is influenced by common polygenic and de novo variation. We a... more Autism spectrum disorder (ASD) risk is influenced by common polygenic and de novo variation. We aimed to clarify the influence of polygenic risk for ASD and to identify subgroups of ASD cases, including those with strongly acting de novo variants, in which polygenic risk is relevant. Using a novel approach called the polygenic transmission disequilibrium test and data from 6,454 families with a child with ASD, we show that polygenic risk for ASD, schizophrenia, and greater educational attainment is over-transmitted to children with ASD. These findings hold independent of proband IQ. We find that polygenic variation contributes additively to risk in ASD cases who carry a strongly acting de novo variant. Lastly, we show that elements of polygenic risk are independent and differ in their relationship with phenotype. These results confirm that the genetic influences on ASD are additive and suggest that they create risk through at least partially distinct etiologic pathways.

Research paper thumbnail of Gene-ontology enrichment analysis in two independent family-based samples highlights biologically plausible processes for autism spectrum disorders

European Journal of Human Genetics, 2011

Recent genome-wide association studies (GWAS) have implicated a range of genes from discrete biol... more Recent genome-wide association studies (GWAS) have implicated a range of genes from discrete biological pathways in the aetiology of autism. However, despite the strong influence of genetic factors, association studies have yet to identify statistically robust, replicated major effect genes or SNPs. We apply the principle of the SNP ratio test methodology described by O'Dushlaine et al to over 2100 families from the Autism Genome Project (AGP). Using a two-stage design we examine association enrichment in 5955 unique gene-ontology classifications across four groupings based on two phenotypic and two ancestral classifications. Based on estimates from simulation we identify excess of association enrichment across all analyses. We observe enrichment in association for sets of genes involved in diverse biological processes, including pyruvate metabolism, transcription factor activation, cell-signalling and cell-cycle regulation. Both genes and processes that show enrichment have previously been examined in autistic disorders and offer biologically plausibility to these findings.

Research paper thumbnail of Mutation screening and association analysis of six candidate genes for autism on chromosome 7q

European Journal of Human Genetics, 2004

Genetic studies have provided evidence for an autism susceptibility locus (AUTS1) on chromosome 7... more Genetic studies have provided evidence for an autism susceptibility locus (AUTS1) on chromosome 7q. Screening for mutations in six genes mapping to 7q, CUTL1, SRPK2, SYPL, LAMB1, NRCAM and PTPRZ1 in 48 unrelated individuals with autism led to the identification of several new coding variants in the genes CUTL1, LAMB1 and PTPRZ1. Analysis of genetic variants provided evidence for association with autism for one of the new missense changes identified in LAMB1; this effect was stronger in a subgroup of affected male sibling pair families, implying a possible specific sex-related effect for this variant. Association was also detected for several polymorphisms in the promoter and untranslated region of NRCAM, suggesting that alterations in expression of this gene may be linked to autism susceptibility.

Research paper thumbnail of Functional impact of global rare copy number variation in autism spectrum disorders

Nature, Jan 15, 2010

The autism spectrum disorders (ASDs) are a group of conditions characterized by impairments in re... more The autism spectrum disorders (ASDs) are a group of conditions characterized by impairments in reciprocal social interaction and communication, and the presence of restricted and repetitive behaviours. Individuals with an ASD vary greatly in cognitive development, which can range from above average to intellectual disability. Although ASDs are known to be highly heritable ( approximately 90%), the underlying genetic determinants are still largely unknown. Here we analysed the genome-wide characteristics of rare…

Research paper thumbnail of Further Delineation of Deletion lp36 Syndrome in 60 Patients : A Recognizable Phenotype and Common Cause of Developmental Delay and Mental Retardation

Research paper thumbnail of Perinatal distress in 1p36 deletion syndrome can mimic hypoxic ischemic encephalopathy

American Journal of Medical Genetics Part A

Research paper thumbnail of Risk of hepatic neoplasms in Wolf-Hirschhorn syndrome (4p-): Four new cases and review of the literature

American journal of medical genetics. Part A, Jan 5, 2018

Wolf-Hirschhorn syndrome (WHS) is a rare contiguous gene deletion disorder characterized by disti... more Wolf-Hirschhorn syndrome (WHS) is a rare contiguous gene deletion disorder characterized by distinctive craniofacial features, prenatal/postnatal growth deficiency, intellectual disability, and seizures. Various malformations of internal organs are also seen. Neoplasia has not been documented as a typical feature of WHS. We review the three prior reports of hepatic neoplasia in WHS and add four previously unreported individuals. We propose that, in the context of the rarity of WHS, these seven cases suggest that hepatocellular neoplasia may be a feature of WHS.

Research paper thumbnail of De Novo Variants in the F-Box Protein FBXO11 in 20 Individuals with a Variable Neurodevelopmental Disorder

American journal of human genetics, Jan 2, 2018

Next-generation sequencing combined with international data sharing has enormously facilitated id... more Next-generation sequencing combined with international data sharing has enormously facilitated identification of new disease-associated genes and mutations. This is particularly true for genetically extremely heterogeneous entities such as neurodevelopmental disorders (NDDs). Through exome sequencing and world-wide collaborations, we identified and assembled 20 individuals with de novo variants in FBXO11. They present with mild to severe developmental delay associated with a range of features including short (4/20) or tall (2/20) stature, obesity (5/20), microcephaly (4/19) or macrocephaly (2/19), behavioral problems (17/20), seizures (5/20), cleft lip or palate or bifid uvula (3/20), and minor skeletal anomalies. FBXO11 encodes a member of the F-Box protein family, constituting a subunit of an E3-ubiquitin ligase complex. This complex is involved in ubiquitination and proteasomal degradation and thus in controlling critical biological processes by regulating protein turnover. The i...

Research paper thumbnail of A survey of antiepileptic drug responses identifies drugs with potential efficacy for seizure control in Wolf-Hirschhorn syndrome

Epilepsy & behavior : E&B, Jan 22, 2018

Seizures are present in over 90% of infants and children with Wolf-Hirschhorn syndrome (WHS). Whe... more Seizures are present in over 90% of infants and children with Wolf-Hirschhorn syndrome (WHS). When present, they significantly affect quality of life. The goal of this study was to use caregiver reports to describe the comparative efficacies of commonly used antiepileptic medications in a large population of individuals with WHS. A web-based, confidential caregiver survey was developed to capture seizure semiology and a chronologic record of seizure treatments as well as responses to each treatment. Adverse events for each drug were also cataloged. We received 141 complete survey responses (47% response rate) describing the seizures of individuals ranging in age from 4months to 61years (90 females: 51 males). Using the Early Childhood Epilepsy Severity Scale (E-Chess), WHS-associated seizures are demonstrably severe regardless of deletion size. The best-performing antiepileptic drugs (AEDs) for controlling seizures in this cohort were broad spectrum drugs clobazam, levetiracetam, an...