Marco Fichera - Academia.edu (original) (raw)
Papers by Marco Fichera
American Journal of Medical Genetics Part A, 2015
The ability to identify the clinical nature of the recurrent duplication of chromosome 17q12 has ... more The ability to identify the clinical nature of the recurrent duplication of chromosome 17q12 has been limited by its rarity and the diverse range of phenotypes associated with this genomic change. In order to further define the clinical features of affected patients, detailed clinical information was collected in the largest series to date (30 patients and 2 of their siblings) through a multi-institutional collaborative effort. The majority of patients presented with developmental delays varying from mild to severe. Though dysmorphic features were commonly reported, patients do not have consistent and recognizable features. Cardiac, ophthalmologic, growth, behavioral, and other abnormalities were each present in a subset of patients. The newly associated features potentially resulting from 17q12 duplication include height and weight above the 95th percentile, cataracts, microphthalmia, coloboma, astigmatism, tracheomalacia, cutaneous mosaicism, pectus excavatum, scoliosis, hypermobility, hypospadias, diverticulum of Kommerell, pyloric stenosis, and pseudohypoparathryoidism. The majority of duplications were inherited with some carrier parents reporting learning disabilities or microcephaly. We identified additional, potentially contributory copy number changes in a subset of patients, including one patient each with 16p11.2 deletion and 15q13.3 deletion. Our data further define and expand the clinical spectrum associated with duplications of 17q12 and provide support for the role of genomic modifiers contributing to phenotypic variability. © 2015 Wiley Periodicals, Inc.
Journal of medical genetics, 1999
We report on the evaluation of a strategy for screening for XNP/ATR-X mutations in males with men... more We report on the evaluation of a strategy for screening for XNP/ATR-X mutations in males with mental retardation and associated dysmorphology. Because nearly half of the mutations in this gene reported to date fall into a short 300 bp region of the transcript, we decided to focus in this region and to extend the mutation analysis to cases with a negative family history. This study includes 21 mentally retarded male patients selected because they had severe mental retardation and a typical facial appearance. The presence of haemoglobin H or urogenital abnormalities was not considered critical for inclusion in this study. We have identified six mutations which represents a mutation detection rate of 28%. This figure is high enough for us to propose this strategy as a valid first level of screening in a selected subset of males with mental retardation. This approach is simple, does not require RNA preparation, does not involve time consuming mutation detection methods, and can thus be ...
Molecular Cytogenetics, 2014
Despite the extensive use of chromosomal microarray technologies in patients with neurodevelopmen... more Despite the extensive use of chromosomal microarray technologies in patients with neurodevelopmental disorders has permitted the identification of an increasing number of causative submicroscopic rearrangements throughout the genome, constitutional duplications involving chromosome 1q22 have seldom been described in those patients. We report on a pedigree with seven affected members showing varying degrees of behavioural and emotional disturbances including general anxiety disorder, mood disorders, and intellectual disability. Two adult female patients also showed late onset autoimmune inflammatory responses characterized by alopecia, skin ulcers secondary to inflammatory vasculitis, interstitial lung disease, and Raynaud's phenomenon. Array-CGH analysis identified in the affected individuals a 290 Kb microduplication in the chromosome 1q22. The rearrangement involves eleven known genes and is not present in the databases of polymorphic copy number variants. The rearrangement segregates with the neurological clinical features observed in our patients, suggesting that dosage imbalance of one or more genes in this genomic region may lead to the observed phenotype. The association between the microduplication and the inflammatory disease is much less evident. Additional reported patients carrying similar microduplications are needed to clarify this aspect.
Neuromuscular Disorders, 2004
The most common form of autosomal dominant hereditary spastic paraplegia is caused by mutations i... more The most common form of autosomal dominant hereditary spastic paraplegia is caused by mutations in the gene encoding spastin (SPG4), a member of the AAA family of ATPases. In the current study, we designed a denaturing high-performance liquid chromatography based protocol for the analysis of the SPG4 gene. Using this method, we detected two novel missense mutations, 1375A > G (R459G) and 1378C > T (R460C), one previously described five bases deletion (1215_1219del) and three polymorphic changes. This study suggests that denaturing high-performance liquid chromatography would be a fast and reliable tool in the investigation of the molecular defects in the SPG4 gene.
Journal of Medical Genetics, 2009
Journal of Genetics, 2011
Human Mutation, 2003
Molecular defects affecting the ATRX gene lead to the ATRX syndrome (alpha thalassemia/mental ret... more Molecular defects affecting the ATRX gene lead to the ATRX syndrome (alpha thalassemia/mental retardation syndrome, X-linked), characterized by severe mental retardation, microcephaly, distinct facial dysmorphism, and genital abnormalities, as well as a wide spectrum of other pathological features. Alpha thalassemia is frequent but does not represent a constant characteristic of the syndrome. An expanding phenotype of the ATRX gene (a RAD54 homologue encoding a putative zinc-finger helicase) has been demonstrated as a result of the association of single mutations with specific X-linked mental retardation syndromes. To date, mutational analysis of the gene has been based on direct DNA sequencing or using methods with a lower detection rate. In this paper, we present a broad-range DGGE method for single-step mutation scanning of the entire open reading frame (ORF) and canonical splice sites of the gene. Using this method, we successfully identified five novel sequence changes in the ATRX gene, including four missense mutations (K1733E, R2085C, D2136N, T2169A) and one polymorphism (IVS5+35G>A).
European Journal of Pediatrics, 2010
X-linked hydrocephalus is due to mutations in the L1 neuronal cell adhesion molecule (L1CAM) gene... more X-linked hydrocephalus is due to mutations in the L1 neuronal cell adhesion molecule (L1CAM) gene. L1 protein plays a key role in neurite outgrowth, axonal guidance, and pathfinding during the development of the nervous system. We report on a familial case diagnosed by prenatal ultrasonographic examination, with cerebellar hypoplasia, agenesis of the corpus callosum, and the bilateral overlapping of the second and third fingers of the hand. Sequencing of the L1CAM gene showed a novel missense mutation in exon 14: transition of a guanine to cytosine at position 1777 (c.1777G>C), which led to an amino acid change of alanine to proline at position 593 (Ala593Pro) in the sixth immunoglobulin domain of the L1 protein. The L1CAM mutation testing should be considered in fetuses with ultrasonographic signs of hydrocephalus and a positive family history compatible with X-linked inheritance. We agree with previous reports that suggest also considering limb abnormalities other than adducted thumbs in addition to classical neurological disgenesis, as characteristic for L1-disease.
Clinical Nuclear Medicine, 1997
Clinical Genetics, 2007
... P Failla 1 ,; C Romano 1,* ,; A Alberti 1 ,; A Vasta 2 ,; S Buono 2 ,; L Castiglia 3 ,; D Luc... more ... P Failla 1 ,; C Romano 1,* ,; A Alberti 1 ,; A Vasta 2 ,; S Buono 2 ,; L Castiglia 3 ,; D Luciano 3 ,; D Di Benedetto 3 ,; M Fichera 3 ,; O Galesi 3. Article first published online: 10 MAY 2007. DOI: 10.1111/j.1399-0004.2007.00819.x. 2007 Blackwell Munksgaard. Issue. Clinical Genetics ...
American Journal of Medical Genetics Part A, 2011
Developmental and epileptic encephalopathies (DEEs) are genetically heterogenous conditions, ofte... more Developmental and epileptic encephalopathies (DEEs) are genetically heterogenous conditions, often characterized by early onset, EEG interictal epileptiform abnormalities, polymorphous and drug-resistant seizures, and neurodevelopmental impairments. In this study, we investigated the genetic defects in two siblings who presented with severe DEE, microcephaly, spastic tetraplegia, diffuse brain hypomyelination, cerebellar atrophy, short stature, and kyphoscoliosis. Whole exome next-generation sequencing (WES) identified in both siblings a homozygous non-sense variant in the ACTL6B gene (NM_016188:c.820C>T;p.Gln274*) coding for a subunit of the neuron-specific chromatin remodeling complex nBAF. To further support these findings, a targeted ACTL6B sequencing assay was performed on a cohort of 85 unrelated DEE individuals, leading to the identification of a homozygous missense variant (NM_016188:c.1045G>A;p.Gly349Ser) in a patient. This variant did not segregate in the unaffected siblings in this family and was classified as deleterious by several prediction softwares. Interestingly, in both families, homozygous patients shared a rather homogeneous phenotype. Very few patients with ACTL6B gene variants have been sporadically reported in WES cohort studies of patients with neurodevelopmental disorders and/or congenital brain malformations. However, the limited number of patients with incomplete clinical information yet reported in the literature did not allow to establish a strong gene-disease association. Here, we provide additional genetic and clinical data on three new cases that support the pathogenic role of ACTL6B gene mutation in a syndromic form of DEE.
In this study, we used deletions at 22q13, which represent a substantial source of human patholog... more In this study, we used deletions at 22q13, which represent a substantial source of human pathology (Phelan/McDermid syndrome), as a model for investigating the molecular mechanisms of terminal deletions that are currently poorly understood. We characterized at the molecular level the genomic rearrangement in 44 unrelated patients with 22q13 monosomy resulting from simple terminal deletions (72%), ring chromosomes (14%), and unbalanced translocations (7%). We also discovered interstitial deletions between 17–74 kb in 9% of the patients. Haploinsufficiency of the SHANK3 gene, confirmed in all rearrangements, is very likely the cause of the major neurological features associated with PMS. SHANK3 mutations can also result in language and/or social interaction disabilities. We determined the breakpoint junctions in 29 cases, providing a realistic snapshot of the variety of mechanisms driving non-recurrent deletion and repair at chromosome ends. De novo telomere synthesis and telomere capture are used to repair terminal deletions; non-homologous end-joining or microhomology-mediated break-induced replication is probably involved in ring 22 formation and translocations; non-homologous end-joining and fork stalling and template switching prevail in cases with interstitial 22q13.3. For the first time, we also demonstrated that distinct stabilizing events of the same terminal deletion can occur in different early embryonic cells, proving that terminal deletions can be repaired by multistep healing events and supporting the recent hypothesis that rare pathogenic germline rearrangements may have mitotic origin. Finally, the progressive clinical deterioration observed throughout the longitudinal medical history of three subjects over forty years supports the hypothesis of a role for SHANK3 haploinsufficiency in neurological deterioration, in addition to its involvement in the neurobehavioral phenotype of PMS.
Archives of Neurology, 2012
The American Journal of Human Genetics, 2009
American Journal of Medical Genetics Part A, 2014
American Journal of Medical Genetics Part A, 2015
The ability to identify the clinical nature of the recurrent duplication of chromosome 17q12 has ... more The ability to identify the clinical nature of the recurrent duplication of chromosome 17q12 has been limited by its rarity and the diverse range of phenotypes associated with this genomic change. In order to further define the clinical features of affected patients, detailed clinical information was collected in the largest series to date (30 patients and 2 of their siblings) through a multi-institutional collaborative effort. The majority of patients presented with developmental delays varying from mild to severe. Though dysmorphic features were commonly reported, patients do not have consistent and recognizable features. Cardiac, ophthalmologic, growth, behavioral, and other abnormalities were each present in a subset of patients. The newly associated features potentially resulting from 17q12 duplication include height and weight above the 95th percentile, cataracts, microphthalmia, coloboma, astigmatism, tracheomalacia, cutaneous mosaicism, pectus excavatum, scoliosis, hypermobility, hypospadias, diverticulum of Kommerell, pyloric stenosis, and pseudohypoparathryoidism. The majority of duplications were inherited with some carrier parents reporting learning disabilities or microcephaly. We identified additional, potentially contributory copy number changes in a subset of patients, including one patient each with 16p11.2 deletion and 15q13.3 deletion. Our data further define and expand the clinical spectrum associated with duplications of 17q12 and provide support for the role of genomic modifiers contributing to phenotypic variability. © 2015 Wiley Periodicals, Inc.
Journal of medical genetics, 1999
We report on the evaluation of a strategy for screening for XNP/ATR-X mutations in males with men... more We report on the evaluation of a strategy for screening for XNP/ATR-X mutations in males with mental retardation and associated dysmorphology. Because nearly half of the mutations in this gene reported to date fall into a short 300 bp region of the transcript, we decided to focus in this region and to extend the mutation analysis to cases with a negative family history. This study includes 21 mentally retarded male patients selected because they had severe mental retardation and a typical facial appearance. The presence of haemoglobin H or urogenital abnormalities was not considered critical for inclusion in this study. We have identified six mutations which represents a mutation detection rate of 28%. This figure is high enough for us to propose this strategy as a valid first level of screening in a selected subset of males with mental retardation. This approach is simple, does not require RNA preparation, does not involve time consuming mutation detection methods, and can thus be ...
Molecular Cytogenetics, 2014
Despite the extensive use of chromosomal microarray technologies in patients with neurodevelopmen... more Despite the extensive use of chromosomal microarray technologies in patients with neurodevelopmental disorders has permitted the identification of an increasing number of causative submicroscopic rearrangements throughout the genome, constitutional duplications involving chromosome 1q22 have seldom been described in those patients. We report on a pedigree with seven affected members showing varying degrees of behavioural and emotional disturbances including general anxiety disorder, mood disorders, and intellectual disability. Two adult female patients also showed late onset autoimmune inflammatory responses characterized by alopecia, skin ulcers secondary to inflammatory vasculitis, interstitial lung disease, and Raynaud's phenomenon. Array-CGH analysis identified in the affected individuals a 290 Kb microduplication in the chromosome 1q22. The rearrangement involves eleven known genes and is not present in the databases of polymorphic copy number variants. The rearrangement segregates with the neurological clinical features observed in our patients, suggesting that dosage imbalance of one or more genes in this genomic region may lead to the observed phenotype. The association between the microduplication and the inflammatory disease is much less evident. Additional reported patients carrying similar microduplications are needed to clarify this aspect.
Neuromuscular Disorders, 2004
The most common form of autosomal dominant hereditary spastic paraplegia is caused by mutations i... more The most common form of autosomal dominant hereditary spastic paraplegia is caused by mutations in the gene encoding spastin (SPG4), a member of the AAA family of ATPases. In the current study, we designed a denaturing high-performance liquid chromatography based protocol for the analysis of the SPG4 gene. Using this method, we detected two novel missense mutations, 1375A > G (R459G) and 1378C > T (R460C), one previously described five bases deletion (1215_1219del) and three polymorphic changes. This study suggests that denaturing high-performance liquid chromatography would be a fast and reliable tool in the investigation of the molecular defects in the SPG4 gene.
Journal of Medical Genetics, 2009
Journal of Genetics, 2011
Human Mutation, 2003
Molecular defects affecting the ATRX gene lead to the ATRX syndrome (alpha thalassemia/mental ret... more Molecular defects affecting the ATRX gene lead to the ATRX syndrome (alpha thalassemia/mental retardation syndrome, X-linked), characterized by severe mental retardation, microcephaly, distinct facial dysmorphism, and genital abnormalities, as well as a wide spectrum of other pathological features. Alpha thalassemia is frequent but does not represent a constant characteristic of the syndrome. An expanding phenotype of the ATRX gene (a RAD54 homologue encoding a putative zinc-finger helicase) has been demonstrated as a result of the association of single mutations with specific X-linked mental retardation syndromes. To date, mutational analysis of the gene has been based on direct DNA sequencing or using methods with a lower detection rate. In this paper, we present a broad-range DGGE method for single-step mutation scanning of the entire open reading frame (ORF) and canonical splice sites of the gene. Using this method, we successfully identified five novel sequence changes in the ATRX gene, including four missense mutations (K1733E, R2085C, D2136N, T2169A) and one polymorphism (IVS5+35G>A).
European Journal of Pediatrics, 2010
X-linked hydrocephalus is due to mutations in the L1 neuronal cell adhesion molecule (L1CAM) gene... more X-linked hydrocephalus is due to mutations in the L1 neuronal cell adhesion molecule (L1CAM) gene. L1 protein plays a key role in neurite outgrowth, axonal guidance, and pathfinding during the development of the nervous system. We report on a familial case diagnosed by prenatal ultrasonographic examination, with cerebellar hypoplasia, agenesis of the corpus callosum, and the bilateral overlapping of the second and third fingers of the hand. Sequencing of the L1CAM gene showed a novel missense mutation in exon 14: transition of a guanine to cytosine at position 1777 (c.1777G>C), which led to an amino acid change of alanine to proline at position 593 (Ala593Pro) in the sixth immunoglobulin domain of the L1 protein. The L1CAM mutation testing should be considered in fetuses with ultrasonographic signs of hydrocephalus and a positive family history compatible with X-linked inheritance. We agree with previous reports that suggest also considering limb abnormalities other than adducted thumbs in addition to classical neurological disgenesis, as characteristic for L1-disease.
Clinical Nuclear Medicine, 1997
Clinical Genetics, 2007
... P Failla 1 ,; C Romano 1,* ,; A Alberti 1 ,; A Vasta 2 ,; S Buono 2 ,; L Castiglia 3 ,; D Luc... more ... P Failla 1 ,; C Romano 1,* ,; A Alberti 1 ,; A Vasta 2 ,; S Buono 2 ,; L Castiglia 3 ,; D Luciano 3 ,; D Di Benedetto 3 ,; M Fichera 3 ,; O Galesi 3. Article first published online: 10 MAY 2007. DOI: 10.1111/j.1399-0004.2007.00819.x. 2007 Blackwell Munksgaard. Issue. Clinical Genetics ...
American Journal of Medical Genetics Part A, 2011
Developmental and epileptic encephalopathies (DEEs) are genetically heterogenous conditions, ofte... more Developmental and epileptic encephalopathies (DEEs) are genetically heterogenous conditions, often characterized by early onset, EEG interictal epileptiform abnormalities, polymorphous and drug-resistant seizures, and neurodevelopmental impairments. In this study, we investigated the genetic defects in two siblings who presented with severe DEE, microcephaly, spastic tetraplegia, diffuse brain hypomyelination, cerebellar atrophy, short stature, and kyphoscoliosis. Whole exome next-generation sequencing (WES) identified in both siblings a homozygous non-sense variant in the ACTL6B gene (NM_016188:c.820C>T;p.Gln274*) coding for a subunit of the neuron-specific chromatin remodeling complex nBAF. To further support these findings, a targeted ACTL6B sequencing assay was performed on a cohort of 85 unrelated DEE individuals, leading to the identification of a homozygous missense variant (NM_016188:c.1045G>A;p.Gly349Ser) in a patient. This variant did not segregate in the unaffected siblings in this family and was classified as deleterious by several prediction softwares. Interestingly, in both families, homozygous patients shared a rather homogeneous phenotype. Very few patients with ACTL6B gene variants have been sporadically reported in WES cohort studies of patients with neurodevelopmental disorders and/or congenital brain malformations. However, the limited number of patients with incomplete clinical information yet reported in the literature did not allow to establish a strong gene-disease association. Here, we provide additional genetic and clinical data on three new cases that support the pathogenic role of ACTL6B gene mutation in a syndromic form of DEE.
In this study, we used deletions at 22q13, which represent a substantial source of human patholog... more In this study, we used deletions at 22q13, which represent a substantial source of human pathology (Phelan/McDermid syndrome), as a model for investigating the molecular mechanisms of terminal deletions that are currently poorly understood. We characterized at the molecular level the genomic rearrangement in 44 unrelated patients with 22q13 monosomy resulting from simple terminal deletions (72%), ring chromosomes (14%), and unbalanced translocations (7%). We also discovered interstitial deletions between 17–74 kb in 9% of the patients. Haploinsufficiency of the SHANK3 gene, confirmed in all rearrangements, is very likely the cause of the major neurological features associated with PMS. SHANK3 mutations can also result in language and/or social interaction disabilities. We determined the breakpoint junctions in 29 cases, providing a realistic snapshot of the variety of mechanisms driving non-recurrent deletion and repair at chromosome ends. De novo telomere synthesis and telomere capture are used to repair terminal deletions; non-homologous end-joining or microhomology-mediated break-induced replication is probably involved in ring 22 formation and translocations; non-homologous end-joining and fork stalling and template switching prevail in cases with interstitial 22q13.3. For the first time, we also demonstrated that distinct stabilizing events of the same terminal deletion can occur in different early embryonic cells, proving that terminal deletions can be repaired by multistep healing events and supporting the recent hypothesis that rare pathogenic germline rearrangements may have mitotic origin. Finally, the progressive clinical deterioration observed throughout the longitudinal medical history of three subjects over forty years supports the hypothesis of a role for SHANK3 haploinsufficiency in neurological deterioration, in addition to its involvement in the neurobehavioral phenotype of PMS.
Archives of Neurology, 2012
The American Journal of Human Genetics, 2009
American Journal of Medical Genetics Part A, 2014