Virginia Nunes - Academia.edu (original) (raw)
Papers by Virginia Nunes
Endocrine Abstracts, 2015
BMC Pediatrics, 2013
Background: Wolfram, Alström and Bardet-Biedl (WABB) syndromes are rare diseases with overlapping... more Background: Wolfram, Alström and Bardet-Biedl (WABB) syndromes are rare diseases with overlapping features of multiple sensory and metabolic impairments, including diabetes mellitus, which have caused diagnostic confusion. There are as yet no specific treatments available, little or no access to well characterized cohorts of patients, and limited information on the natural history of the diseases. We aim to establish a Europe-wide registry for these diseases to inform patient care and research. Methods: EURO-WABB is an international multicenter large-scale observational study capturing longitudinal clinical and outcome data for patients with WABB diagnoses. Three hundred participants will be recruited over 3 years from different sites throughout Europe. Comprehensive clinical, genetic and patient experience data will be collated into an anonymized disease registry. Data collection will be web-based, and forms part of the project's Virtual Research and Information Environment (VRIE). Participants who haven't undergone genetic diagnostic testing for their condition will be able to do so via the project. Conclusions: The registry data will be used to increase the understanding of the natural history of WABB diseases, to serve as an evidence base for clinical management, and to aid the identification of opportunities for intervention to stop or delay the progress of the disease. The detailed clinical characterisation will allow inclusion of patients into studies of novel treatment interventions, including targeted interventions in small scale open label studies; and enrolment into multi-national clinical trials. The registry will also support wider access to genetic testing, and encourage international collaborations for patient benefit.
The American Journal of Human Genetics, May 1, 1996
Wolfram syndrome (MIM 222300) is characterized by optic atrophy, diabetes mellitus, diabetes insi... more Wolfram syndrome (MIM 222300) is characterized by optic atrophy, diabetes mellitus, diabetes insipidus, neurosensory hearing loss, urinary tract abnormalities, and neurological dysfunction. The association of clinical manifestations in tissues and organs unrelated functionally or embryologically suggested the possibility of a mitochondrial implication in the disease, which has been demonstrated in two sporadic cases. Nonetheless, familial studies suggested an autosomal recessive mode of transmission, and recent data demonstrated linkage with markers on the short arm of human chromosome 4. The patient reported here, as well as her parents and unaffected sister, carried a heteroplasmic 8.5-kb deletion in mtDNA. The deletion accounted for 23% of mitochondrial genomes in lymphocytes from the patient and -5% in the tissues studied from members of her family. The presence of the deletion in the patient in a proportion higher than in her unaffected parents suggests a putative defect in a nuclear gene that acts at the mitochondrial level.
Human Genetics, Apr 1, 1993
We have determined the frequency of deletion AF508 and mutation G542X, a nonsense mutation in exo... more We have determined the frequency of deletion AF508 and mutation G542X, a nonsense mutation in exon 11 of the cystic fibrosis (CF) gene, in a sample of 400 Spanish CF families. Mutation G542X represents 8% of the total number of CF mutations in Spain, making it the second most common mutation after the AF508 deletion, which accounts for 48% of CF chromosomes. G542X has a higher frequency in the Mediterranean coastal area (14%) and in the Canary Islands (25%). About 70% of G542X chromosomes are from Andalucia, Mtircia, Valencia, Catalunya and the Canary Islands. The AF508 deletion has its highest frequency in the Basque Country (83%). Mutation G542X is associated with the same rare haplotype that is found in association with the AF508 mutation. The haplotype homogeneity found for G542X, even when intragenic microsatellites (IVS8CA, IVS17BTA and IVS17BCA) are considered, allows us to postulate that this mutation arose from a single mutational event. The geographic distribution of mutations AF508 and G542X suggests that AF508 was present in the Iberian Peninsula before the Indo-European invasions, and that G542X was introduced into Spain, via the Mediterranean Sea, probably by the Phoenicians, between 2500 and 3000 years ago.
Pediatric endocrinology reviews : PER, 2006
Wolfram syndrome (WS, OMIM 22233), is a rare, autosomal recessive, and neurodegenerative disease.... more Wolfram syndrome (WS, OMIM 22233), is a rare, autosomal recessive, and neurodegenerative disease. The syndrome is also known as DIDMOAD, the acronym for diabetes insipidus diabetes mellitus, optic atrophy and deafness, which summarizes the main clinical features, among many others, in WS patients. The gene associated with the syndrome, called WFS1, is located in the 4p16.1 region. The WFS1 gene encodes for a transmembrane protein located in the endoplasmic reticulum. Although the function of the WFS1 protein remains unknown, it is thought to be related with intracellular calcium homeostasis. The pattern of presentation of WS suggested the existence of mitochondrial impairment. Mitochondrial DNA rearrangements were detected in some patients, thus confirming that hypothesis. Recently, a particular WS phenotype has been described linked with the long arm of chromosome 4. This work aims to summarize the current knowledge about this disease that causes a heterogeneous phenotype and has a...
Medicina Clinica, Apr 1, 1989
A molecular study of 36 Spanish families with cystic fibrosis (CF) patients is reported. The anal... more A molecular study of 36 Spanish families with cystic fibrosis (CF) patients is reported. The analysis of seven DNA polymorphisms adjacent to the CF gene permitted the diagnosis of 95% of the probable carriers and the antenatal diagnosis in the seven cases in which it was requested. The application of recombinant DNA techniques to the study of CF by means of the analysis of DNA markers linked to the CF gene is useful, not only to identify the latter, but also as a reference to investigate its molecular pathology and for diagnostic purposes in high risk families (families with involved members).
International Journal of Cardiology, 2006
Mutations in mtDNA have been implicated in the development of hypertrophic cardiomyopathy (HCM), ... more Mutations in mtDNA have been implicated in the development of hypertrophic cardiomyopathy (HCM), including cases from families with a maternal transmission. Alleles at several polymorphic sites in mtDNA define different haplogroups and some of these haplogroups have been involved in the risk of developing several diseases in which mitochondria should be involved. We analysed the association between the nine common European haplogroups and HCM. A total of 130 Spanish patients and 300 healthy controls were genotyped for eight mitochondrial single nucleotide polymorphisms (SNPs) through polymerase chain reaction followed by digestion with a restriction enzyme (PCR-RFLP). We compared the frequencies of these polymorphisms and mitochondrial haplogroups between patients and controls. Haplogroup T, specifically defined by 13368A, was significantly involved in the risk of developing HCM in our population (p=0.007; OR=2.42; 95% CI=1.25-4.67). Our data suggest that the genetic variation at the mitochondrial genome could significantly contribute to the risk for HCM.
European Journal of Human Genetics, 2002
Wolfram syndrome (WS) is an autosomal recessive neurodegenerative disorder characterised by early... more Wolfram syndrome (WS) is an autosomal recessive neurodegenerative disorder characterised by early onset diabetes mellitus and progressive optic atrophy, as well as other clinical features such as deafness, diabetes insipida, renal tract abnormalities and diverse psychiatric illnesses. A gene responsible for WS was identified in 4p16.1 (WFS1). It encodes a putative 890 amino acid transmembrane protein expressed in a wide spectrum of tissues. Recently, a new locus for WS has been located on 4q22-24, providing additional evidence for the genetic heterogeneity of this syndrome. We have studied the presence of WFS1 variants in three groups of individuals: patients with diabetes mellitus, patients with deafness and patients with both conditions. A fourth group of healthy subjects was used as control. We have identified a total of 18 nucleotide changes in the WFS1 gene: three mutations and 15 polymorphisms. Six of these changes were previously undescribed. Four of the 15 polymorphisms studied among the patients group present statistical differences in the allelic and genotypic distribution when comparing affected vs control groups.
Hum Genet, 1992
W e describe a rare single-strand c o n f o r m a t i o n
Medicina Clinica, Mar 13, 1999
Diagn Mol Pathol, 2005
Touch preparations or imprints have been extensively used in cytogenetics to avoid primary cultur... more Touch preparations or imprints have been extensively used in cytogenetics to avoid primary cultures, especially when studying solid tumors which are hard to grow in vitro. Interphase nuclei studies by FISH have been validated in several sample types; however, to our knowledge, a comparison between both methods when studying clonality has not yet been published. We have performed a comparative FISH study between touch preparations and cultured cells to assess their reliability when studying the aneuploidy of chromosome Y in mosaicism. Our results in 23 samples indicate that aneuploidy of chromosome Y assessed in cells from tissue cultures versus cells obtained from touch preparations from seminal vesicles of patients with prostate cancer is not comparable. The percentage of aneuploid cells is higher in cultured cells. Attention, therefore, must be paid not to overestimating or underestimating the number of aneuploid cells detected when using interphase FISH studies, especially in solid tumors where clonality is very frequent. Also, according to our results, it is reasonable to extrapolate that when performing interphase nuclei studies in paraffin sections or tissue microarray, and therefore underestimations of aneuploidy could be reported. This might be of special relevance if the aneuploidy detected correlates with the tumor progression or might be used as a prognostic factor.
Anales espanoles de pediatria
We have studied 70 carrier cystic fibrosis (CF) families with delta F508 mutation using the polym... more We have studied 70 carrier cystic fibrosis (CF) families with delta F508 mutation using the polymerase chain reaction (P.C.R.). We found that frequency of the mutation in CF chromosomes was 53%. 39% of carrier cystic fibrosis families were informative for the mutation.
Medicina Clínica
The mitochondrial A3243G mutation of the tRNA(Leu) has been described in pedigrees with maternall... more The mitochondrial A3243G mutation of the tRNA(Leu) has been described in pedigrees with maternally inherited diabetes mellitus and deafness. Ten diabetic patients with sensorineural deafness were studied. Polymerase chain reaction and enzyme restriction analysis with Apa I were performed. The mutation was found in heteroplasmy in only one patient (1/10). She was a 43-years-old woman with maternally inherited diabetes and deafness since she was 29. The association of sensorineural deafness and maternal inherited diabetes are the clues to suspect this subtype of diabetes.
The American Journal of Human Genetics
We have delineated the molecular lesions causing j0-thalassemia in Spain, a country that has witn... more We have delineated the molecular lesions causing j0-thalassemia in Spain, a country that has witnessed the passage of different Mediterranean populations over the centuries, in order to evaluate the extent of heterogeneity of these mutations and to make possible simplified prenatal diagnosis of the disorder in that country. The use of the polymerase chain-reaction (PCR) technique to preferentially amplify D-globin DNA sequences that contain the most frequent I-thalassemia mutations in Mediterraneans enabled us to rapidly analyze 58 I-thalassemia alleles in a dot-blot format either by hybridization with allele-specific radiolabeled oligonucleotide probes or by direct sequence analysis of the amplification product. The Spanish population carries seven different P-thalassemia mutations; the nonsense codon 39 is predominant (64%), whereas the IVS1 position 110 mutation, the most common cause of j0-thalassemia in the eastern part of the Mediterranean basin, is underrepresented (8.5%). The IVS1 mutation at position 6 accounts for 15% of the defects and leads to a more severe form of 0+-thalassemia than originally described in most of the patients we studied. In this study, we demonstrate further the usefulness of the dot-blot hybridization of PCR-amplified genomic DNA in both rapid population surveys and prenatal diagnosis of D-thalassemia.
Revista Clínica Española
The prenatal diagnosis in a family carrying the Fragile Chromosome X Syndrome (sex linked mental ... more The prenatal diagnosis in a family carrying the Fragile Chromosome X Syndrome (sex linked mental retardation) has been performed using Recombinant DNA techniques. The use of these techniques together with cytogenetics and prenatal diagnosis using chorial biopsy, have enabled the diagnosis of the disease on a male foetus on the twelfth week of pregnancy. Similarly, we have been able to confirm the carrier state of the mother (proven) and the grand mother, and furthermore, the non affected condition of an older son to this mother. The results obtained reveal the importance of the new molecular techniques applied to the diagnosis of certain diseases with a genetic origin.
Journal of Biological Chemistry
ABSTRACT
Endocrine Abstracts, 2015
BMC Pediatrics, 2013
Background: Wolfram, Alström and Bardet-Biedl (WABB) syndromes are rare diseases with overlapping... more Background: Wolfram, Alström and Bardet-Biedl (WABB) syndromes are rare diseases with overlapping features of multiple sensory and metabolic impairments, including diabetes mellitus, which have caused diagnostic confusion. There are as yet no specific treatments available, little or no access to well characterized cohorts of patients, and limited information on the natural history of the diseases. We aim to establish a Europe-wide registry for these diseases to inform patient care and research. Methods: EURO-WABB is an international multicenter large-scale observational study capturing longitudinal clinical and outcome data for patients with WABB diagnoses. Three hundred participants will be recruited over 3 years from different sites throughout Europe. Comprehensive clinical, genetic and patient experience data will be collated into an anonymized disease registry. Data collection will be web-based, and forms part of the project's Virtual Research and Information Environment (VRIE). Participants who haven't undergone genetic diagnostic testing for their condition will be able to do so via the project. Conclusions: The registry data will be used to increase the understanding of the natural history of WABB diseases, to serve as an evidence base for clinical management, and to aid the identification of opportunities for intervention to stop or delay the progress of the disease. The detailed clinical characterisation will allow inclusion of patients into studies of novel treatment interventions, including targeted interventions in small scale open label studies; and enrolment into multi-national clinical trials. The registry will also support wider access to genetic testing, and encourage international collaborations for patient benefit.
The American Journal of Human Genetics, May 1, 1996
Wolfram syndrome (MIM 222300) is characterized by optic atrophy, diabetes mellitus, diabetes insi... more Wolfram syndrome (MIM 222300) is characterized by optic atrophy, diabetes mellitus, diabetes insipidus, neurosensory hearing loss, urinary tract abnormalities, and neurological dysfunction. The association of clinical manifestations in tissues and organs unrelated functionally or embryologically suggested the possibility of a mitochondrial implication in the disease, which has been demonstrated in two sporadic cases. Nonetheless, familial studies suggested an autosomal recessive mode of transmission, and recent data demonstrated linkage with markers on the short arm of human chromosome 4. The patient reported here, as well as her parents and unaffected sister, carried a heteroplasmic 8.5-kb deletion in mtDNA. The deletion accounted for 23% of mitochondrial genomes in lymphocytes from the patient and -5% in the tissues studied from members of her family. The presence of the deletion in the patient in a proportion higher than in her unaffected parents suggests a putative defect in a nuclear gene that acts at the mitochondrial level.
Human Genetics, Apr 1, 1993
We have determined the frequency of deletion AF508 and mutation G542X, a nonsense mutation in exo... more We have determined the frequency of deletion AF508 and mutation G542X, a nonsense mutation in exon 11 of the cystic fibrosis (CF) gene, in a sample of 400 Spanish CF families. Mutation G542X represents 8% of the total number of CF mutations in Spain, making it the second most common mutation after the AF508 deletion, which accounts for 48% of CF chromosomes. G542X has a higher frequency in the Mediterranean coastal area (14%) and in the Canary Islands (25%). About 70% of G542X chromosomes are from Andalucia, Mtircia, Valencia, Catalunya and the Canary Islands. The AF508 deletion has its highest frequency in the Basque Country (83%). Mutation G542X is associated with the same rare haplotype that is found in association with the AF508 mutation. The haplotype homogeneity found for G542X, even when intragenic microsatellites (IVS8CA, IVS17BTA and IVS17BCA) are considered, allows us to postulate that this mutation arose from a single mutational event. The geographic distribution of mutations AF508 and G542X suggests that AF508 was present in the Iberian Peninsula before the Indo-European invasions, and that G542X was introduced into Spain, via the Mediterranean Sea, probably by the Phoenicians, between 2500 and 3000 years ago.
Pediatric endocrinology reviews : PER, 2006
Wolfram syndrome (WS, OMIM 22233), is a rare, autosomal recessive, and neurodegenerative disease.... more Wolfram syndrome (WS, OMIM 22233), is a rare, autosomal recessive, and neurodegenerative disease. The syndrome is also known as DIDMOAD, the acronym for diabetes insipidus diabetes mellitus, optic atrophy and deafness, which summarizes the main clinical features, among many others, in WS patients. The gene associated with the syndrome, called WFS1, is located in the 4p16.1 region. The WFS1 gene encodes for a transmembrane protein located in the endoplasmic reticulum. Although the function of the WFS1 protein remains unknown, it is thought to be related with intracellular calcium homeostasis. The pattern of presentation of WS suggested the existence of mitochondrial impairment. Mitochondrial DNA rearrangements were detected in some patients, thus confirming that hypothesis. Recently, a particular WS phenotype has been described linked with the long arm of chromosome 4. This work aims to summarize the current knowledge about this disease that causes a heterogeneous phenotype and has a...
Medicina Clinica, Apr 1, 1989
A molecular study of 36 Spanish families with cystic fibrosis (CF) patients is reported. The anal... more A molecular study of 36 Spanish families with cystic fibrosis (CF) patients is reported. The analysis of seven DNA polymorphisms adjacent to the CF gene permitted the diagnosis of 95% of the probable carriers and the antenatal diagnosis in the seven cases in which it was requested. The application of recombinant DNA techniques to the study of CF by means of the analysis of DNA markers linked to the CF gene is useful, not only to identify the latter, but also as a reference to investigate its molecular pathology and for diagnostic purposes in high risk families (families with involved members).
International Journal of Cardiology, 2006
Mutations in mtDNA have been implicated in the development of hypertrophic cardiomyopathy (HCM), ... more Mutations in mtDNA have been implicated in the development of hypertrophic cardiomyopathy (HCM), including cases from families with a maternal transmission. Alleles at several polymorphic sites in mtDNA define different haplogroups and some of these haplogroups have been involved in the risk of developing several diseases in which mitochondria should be involved. We analysed the association between the nine common European haplogroups and HCM. A total of 130 Spanish patients and 300 healthy controls were genotyped for eight mitochondrial single nucleotide polymorphisms (SNPs) through polymerase chain reaction followed by digestion with a restriction enzyme (PCR-RFLP). We compared the frequencies of these polymorphisms and mitochondrial haplogroups between patients and controls. Haplogroup T, specifically defined by 13368A, was significantly involved in the risk of developing HCM in our population (p=0.007; OR=2.42; 95% CI=1.25-4.67). Our data suggest that the genetic variation at the mitochondrial genome could significantly contribute to the risk for HCM.
European Journal of Human Genetics, 2002
Wolfram syndrome (WS) is an autosomal recessive neurodegenerative disorder characterised by early... more Wolfram syndrome (WS) is an autosomal recessive neurodegenerative disorder characterised by early onset diabetes mellitus and progressive optic atrophy, as well as other clinical features such as deafness, diabetes insipida, renal tract abnormalities and diverse psychiatric illnesses. A gene responsible for WS was identified in 4p16.1 (WFS1). It encodes a putative 890 amino acid transmembrane protein expressed in a wide spectrum of tissues. Recently, a new locus for WS has been located on 4q22-24, providing additional evidence for the genetic heterogeneity of this syndrome. We have studied the presence of WFS1 variants in three groups of individuals: patients with diabetes mellitus, patients with deafness and patients with both conditions. A fourth group of healthy subjects was used as control. We have identified a total of 18 nucleotide changes in the WFS1 gene: three mutations and 15 polymorphisms. Six of these changes were previously undescribed. Four of the 15 polymorphisms studied among the patients group present statistical differences in the allelic and genotypic distribution when comparing affected vs control groups.
Hum Genet, 1992
W e describe a rare single-strand c o n f o r m a t i o n
Medicina Clinica, Mar 13, 1999
Diagn Mol Pathol, 2005
Touch preparations or imprints have been extensively used in cytogenetics to avoid primary cultur... more Touch preparations or imprints have been extensively used in cytogenetics to avoid primary cultures, especially when studying solid tumors which are hard to grow in vitro. Interphase nuclei studies by FISH have been validated in several sample types; however, to our knowledge, a comparison between both methods when studying clonality has not yet been published. We have performed a comparative FISH study between touch preparations and cultured cells to assess their reliability when studying the aneuploidy of chromosome Y in mosaicism. Our results in 23 samples indicate that aneuploidy of chromosome Y assessed in cells from tissue cultures versus cells obtained from touch preparations from seminal vesicles of patients with prostate cancer is not comparable. The percentage of aneuploid cells is higher in cultured cells. Attention, therefore, must be paid not to overestimating or underestimating the number of aneuploid cells detected when using interphase FISH studies, especially in solid tumors where clonality is very frequent. Also, according to our results, it is reasonable to extrapolate that when performing interphase nuclei studies in paraffin sections or tissue microarray, and therefore underestimations of aneuploidy could be reported. This might be of special relevance if the aneuploidy detected correlates with the tumor progression or might be used as a prognostic factor.
Anales espanoles de pediatria
We have studied 70 carrier cystic fibrosis (CF) families with delta F508 mutation using the polym... more We have studied 70 carrier cystic fibrosis (CF) families with delta F508 mutation using the polymerase chain reaction (P.C.R.). We found that frequency of the mutation in CF chromosomes was 53%. 39% of carrier cystic fibrosis families were informative for the mutation.
Medicina Clínica
The mitochondrial A3243G mutation of the tRNA(Leu) has been described in pedigrees with maternall... more The mitochondrial A3243G mutation of the tRNA(Leu) has been described in pedigrees with maternally inherited diabetes mellitus and deafness. Ten diabetic patients with sensorineural deafness were studied. Polymerase chain reaction and enzyme restriction analysis with Apa I were performed. The mutation was found in heteroplasmy in only one patient (1/10). She was a 43-years-old woman with maternally inherited diabetes and deafness since she was 29. The association of sensorineural deafness and maternal inherited diabetes are the clues to suspect this subtype of diabetes.
The American Journal of Human Genetics
We have delineated the molecular lesions causing j0-thalassemia in Spain, a country that has witn... more We have delineated the molecular lesions causing j0-thalassemia in Spain, a country that has witnessed the passage of different Mediterranean populations over the centuries, in order to evaluate the extent of heterogeneity of these mutations and to make possible simplified prenatal diagnosis of the disorder in that country. The use of the polymerase chain-reaction (PCR) technique to preferentially amplify D-globin DNA sequences that contain the most frequent I-thalassemia mutations in Mediterraneans enabled us to rapidly analyze 58 I-thalassemia alleles in a dot-blot format either by hybridization with allele-specific radiolabeled oligonucleotide probes or by direct sequence analysis of the amplification product. The Spanish population carries seven different P-thalassemia mutations; the nonsense codon 39 is predominant (64%), whereas the IVS1 position 110 mutation, the most common cause of j0-thalassemia in the eastern part of the Mediterranean basin, is underrepresented (8.5%). The IVS1 mutation at position 6 accounts for 15% of the defects and leads to a more severe form of 0+-thalassemia than originally described in most of the patients we studied. In this study, we demonstrate further the usefulness of the dot-blot hybridization of PCR-amplified genomic DNA in both rapid population surveys and prenatal diagnosis of D-thalassemia.
Revista Clínica Española
The prenatal diagnosis in a family carrying the Fragile Chromosome X Syndrome (sex linked mental ... more The prenatal diagnosis in a family carrying the Fragile Chromosome X Syndrome (sex linked mental retardation) has been performed using Recombinant DNA techniques. The use of these techniques together with cytogenetics and prenatal diagnosis using chorial biopsy, have enabled the diagnosis of the disease on a male foetus on the twelfth week of pregnancy. Similarly, we have been able to confirm the carrier state of the mother (proven) and the grand mother, and furthermore, the non affected condition of an older son to this mother. The results obtained reveal the importance of the new molecular techniques applied to the diagnosis of certain diseases with a genetic origin.
Journal of Biological Chemistry
ABSTRACT