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1.
Clin Genet ; 2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31432501

RESUMO

The rate of genetic diagnosis of French patients with familial pancreatic ductal adenocarcinoma (PDAC) is not known. We report germline genetic testing data from 133 index cases meeting criteria for familial pancreatic cancer (FPC) as well as 87 'FPC-like' index cases who did not fulfilled strict FPC definition but were evocative for a PDAC predisposition. The overall rate of genetic diagnosis (in BRCA1, BRCA2, CDKN2A, and ATM genes) was 8.3% in FPC patients and 4.6% in FPC-like patients, consistent with the literature in other populations. Genetic variants were also identified in FANCA and BAP1 genes, as well as in the CDKN2A p12 transcript. This pancreas-specific transcript is a known key player in driving pancreatic oncogenesis. This might be the first described case of a PDAC genetic predisposition due to a variant in this specific transcript.

2.
Prenat Diagn ; 39(11): 986-992, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31273809

RESUMO

OBJECTIVE: Uniparental disomy (UPD) testing is currently recommended during pregnancy in fetuses carrying a balanced Robertsonian translocation (ROB) involving chromosome 14 or 15, both chromosomes containing imprinted genes. The overall risk that such a fetus presents a UPD has been previously estimated to be around ~0.6-0.8%. However, because UPD are rare events and this estimate has been calculated from a number of studies of limited size, we have reevaluated the risk of UPD in fetuses for whom one of the parents was known to carry a nonhomologous ROB (NHROB). METHOD: We focused our multicentric study on NHROB involving chromosome 14 and/or 15. A total of 1747 UPD testing were performed in fetuses during pregnancy for the presence of UPD(14) and/or UPD(15). RESULT: All fetuses were negative except one with a UPD(14) associated with a maternally inherited rob(13;14). CONCLUSION: Considering these data, the risk of UPD following prenatal diagnosis of an inherited ROB involving chromosome 14 and/or 15 could be estimated to be around 0.06%, far less than the previous estimation. Importantly, the risk of miscarriage following an invasive prenatal sampling is higher than the risk of UPD. Therefore, we do not recommend prenatal testing for UPD for these pregnancies and parents should be reassured.

3.
Eur J Hum Genet ; 27(4): 525-534, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30622331

RESUMO

Split-hand-split-foot malformation (SHFM) is a rare condition that occurs in 1 in 8500-25,000 newborns and accounts for 15% of all limb reduction defects. SHFM is heterogeneous and can be isolated, associated with other malformations, or syndromic. The mode of inheritance is mostly autosomal dominant with incomplete penetrance, but can be X-linked or autosomal recessive. Seven loci are currently known: SHFM1 at 7q21.2q22.1 (DLX5 gene), SHFM2 at Xq26, SHFM3 at 10q24q25, SHFM4 at 3q27 (TP63 gene), SHFM5 at 2q31 and SHFM6 as a result of variants in WNT10B (chromosome 12q13). Duplications at 17p13.3 are seen in SHFM when isolated or associated with long bone deficiency. Tandem genomic duplications at chromosome 10q24 involving at least the DACTYLIN gene are associated with SHFM3. No point variant in any of the genes residing within the region has been identified so far, but duplication of exon 1 of the BTRC gene may explain the phenotype, with likely complex alterations of gene regulation mechanisms that would impair limb morphogenesis. We report on 32 new index cases identified by array-CGH and/or by qPCR, including some prenatal ones, leading to termination for the most severe. Twenty-two cases were presenting with SHFM and 7 with monodactyly only. Three had an overlapping phenotype. Additional findings were identified in 5 (renal dysplasia, cutis aplasia, hypogonadism and agenesis of corpus callosum with hydrocephalus). We present their clinical and radiological findings and review the literature on this rearrangement that seems to be one of the most frequent cause of SHFM.

4.
Genet Med ; 2018 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-29790873

RESUMO

PurposeConstitutional epimutations are an alternative to genetic mutations in the etiology of genetic diseases. Some of these epimutations, termed secondary, correspond to the epigenetic effects of cis-acting genetic defects transmitted to the offspring following a Mendelian inheritance pattern. In Lynch syndrome, a few families with such apparently heritable MLH1 epimutations have been reported so far.MethodsWe designed a long-range polymerase chain reaction next-generation sequencing strategy to screen MLH1 entire gene and applied it to 4 French families with heritable epimutations and 10 additional patients with no proven transmission of their epimutations.ResultsThis strategy successfully detected the insertion of an Alu element in MLH1 coding sequence in one family. Two previously unreported MLH1 variants were also identified in other epimutation carriers: a nucleotide substitution within intron 1 and a single-nucleotide deletion in the 5'-UTR. Detection of a partial MLH1 duplication in another family required multiplex ligation-dependent probe amplification technology. We demonstrated the segregation of these variants with MLH1 methylation and studied the functional consequences of these defects on transcription.ConclusionThis is the largest cohort of patients with MLH1 secondary epimutations associated with a broad spectrum of genetic defects. This study provides further insight into the complexity of molecular mechanisms leading to secondary epimutations.GENETICS in MEDICINE advance online publication, 12 April 2018; doi:10.1038/gim.2018.47.

5.
Am J Hum Genet ; 99(6): 1368-1376, 2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-27889060

RESUMO

Early-onset epileptic encephalopathy (EOEE) represents a heterogeneous group of severe disorders characterized by seizures, interictal epileptiform activity with a disorganized electroencephalography background, developmental regression or retardation, and onset before 1 year of age. Among a cohort of 57 individuals with epileptic encephalopathy, we ascertained two unrelated affected individuals with EOEE associated with developmental impairment and autosomal-recessive variants in AP3B2 by means of whole-exome sequencing. The targeted sequencing of AP3B2 in 86 unrelated individuals with EOEE led to the identification of an additional family. We gathered five additional families with eight affected individuals through the Matchmaker Exchange initiative by matching autosomal-recessive mutations in AP3B2. Reverse phenotyping of 12 affected individuals from eight families revealed a homogeneous EOEE phenotype characterized by severe developmental delay, poor visual contact with optic atrophy, and postnatal microcephaly. No spasticity, albinism, or hematological symptoms were reported. AP3B2 encodes the neuron-specific subunit of the AP-3 complex. Autosomal-recessive variations of AP3B1, the ubiquitous isoform, cause Hermansky-Pudlak syndrome type 2. The only isoform for the δ subunit of the AP-3 complex is encoded by AP3D1. Autosomal-recessive mutations in AP3D1 cause a severe disorder cumulating the symptoms of the AP3B1 and AP3B2 defects.


Assuntos
Complexo 3 de Proteínas Adaptadoras/genética , Subunidades beta do Complexo de Proteínas Adaptadoras/genética , Epilepsia/complicações , Epilepsia/genética , Genes Recessivos/genética , Mutação , Atrofia Óptica/complicações , Atrofia Óptica/genética , Idade de Início , Criança , Pré-Escolar , Deficiências do Desenvolvimento/genética , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Microcefalia/genética , Linhagem , Síndrome
6.
Orphanet J Rare Dis ; 11: 49, 2016 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-27112265

RESUMO

BACKGROUND: Less than 50 patients with FPD/AML (OMIM 601309) have been reported as of today and there may an underestimation. The purpose of this study was to describe the natural history, the haematological features and the genotype-phenotype correlations of this entity in order to, first, screen it better and earlier, before leukaemia occurrence and secondly to optimize appropriate monitoring and treatment, in particular when familial stem cell transplantation is considered. METHODS: We have investigated 41 carriers of RUNX1 alteration belonging to nine unrelated French families with FPD/AML and two syndromic patients, registered in the French network on rare platelet disorders from 2005 to 2015. RESULTS: Five missense, one non-sense, three frameshift mutations and two large deletions involving several genes including RUNX1 were evidenced. The history of familial leukaemia was suggestive of FPD/AML in seven pedigrees, whereas an autosomal dominant pattern of lifelong thrombocytopenia was the clinical presentation of two. Additional syndromic features characterized two large sporadic deletions. Bleeding tendency was mild and thrombocytopenia moderate (>50 x10(9)/L), with normal platelet volume. A functional platelet defect consistent with a δ-granule release defect was found in ten patients regardless of the type of RUNX1 alteration. The incidence of haematological malignancies was higher when the mutated RUNX1 allele was likely to cause a dominant negative effect (19/34) in comparison with loss of function alleles (3/9). A normal platelet count does not rule out the diagnosis of FPD/AML, since the platelet count was found normal for three mutated subjects, a feature that has a direct impact in the search for a related donor in case of allogeneic haematopoietic stem cell transplantation. CONCLUSIONS: Platelet dysfunction suggestive of defective δ-granule release could be of values for the diagnosis of FPD/AML particularly when the clinical presentation is an autosomal dominant thrombocytopenia with normal platelet size in the absence of familial malignancies. The genotype-phenotype correlations might be helpful in genetic counselling and appropriate optimal therapeutic management.


Assuntos
Transtornos Herdados da Coagulação Sanguínea/genética , Transtornos Plaquetários/genética , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Leucemia Mieloide Aguda/genética , Adolescente , Adulto , Criança , Pré-Escolar , Hibridização Genômica Comparativa , Feminino , Estudos de Associação Genética , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Mutação , Linhagem , Trombocitopenia/diagnóstico , Trombocitopenia/genética , Adulto Jovem
7.
Eur J Hum Genet ; 24(1): 99-105, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25873010

RESUMO

To determine if the at-risk single-nucleotide polymorphism (SNP) alleles for colorectal cancer (CRC) could contribute to clinical situations suggestive of an increased genetic risk for CRC, we performed a prospective national case-control study based on highly selected patients (CRC in two first-degree relatives, one before 61 years of age; or CRC diagnosed before 51 years of age; or multiple primary CRCs, the first before 61 years of age; exclusion of Lynch syndrome and polyposes) and controls without personal or familial history of CRC. SNPs were genotyped using SNaPshot, and statistical analyses were performed using Pearson's χ(2) test, Cochran-Armitage test of trend and logistic regression. We included 1029 patients and 350 controls. We confirmed the association of CRC risk with four SNPs, with odds ratio (OR) higher than previously reported: rs16892766 on 8q23.3 (OR: 1.88, 95% confidence interval (CI): 1.30-2.72; P=0.0007); rs4779584 on 15q13.3 (OR: 1.42, CI: 1.11-1.83; P=0.0061) and rs4939827 and rs58920878/Novel 1 on 18q21.1 (OR: 1.49, CI: 1.13-1.98; P=0.007 and OR: 1.49, CI: 1.14-1.95; P=0.0035). We found a significant (P<0.0001) cumulative effect of the at-risk alleles or genotypes with OR at 1.62 (CI: 1.10-2.37), 2.09 (CI: 1.43-3.07), 2.87 (CI: 1.76-4.70) and 3.88 (CI: 1.72-8.76) for 1, 2, 3 and at least 4 at-risk alleles, respectively, and OR at 1.71 (CI: 1.18-2.46), 2.29 (CI: 1.55-3.38) and 6.21 (CI: 2.67-14.42) for 1, 2 and 3 at-risk genotypes, respectively. Combination of SNPs may therefore explain a fraction of clinical situations suggestive of an increased risk for CRC.


Assuntos
Cromossomos Humanos Par 15 , Cromossomos Humanos Par 18 , Cromossomos Humanos Par 8 , Neoplasias Colorretais/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Adulto , Alelos , Estudos de Casos e Controles , Neoplasias Colorretais/diagnóstico , Neoplasias Colorretais/patologia , Feminino , Frequência do Gene , Loci Gênicos , Estudo de Associação Genômica Ampla , Técnicas de Genotipagem , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Estudos Prospectivos , Fatores de Risco
8.
Ann Biol Clin (Paris) ; 73(5): 587-90, 2015 Sep-Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26489818

RESUMO

A pyrimidine 5'-nucleotidase deficiency in an adult is reported. Interestingly, the P5'N-1 deficiency was associated to a polymalformative syndrome and was characterized by a chronic, pancytopenic evolution with concomitant dyserythropoiesis.


Assuntos
5'-Nucleotidase/deficiência , Anemia Hemolítica/genética , Eritrócitos Anormais/enzimologia , Humanos , Masculino , Pancitopenia/etiologia , Adulto Jovem
9.
Am J Med Genet A ; 167(6): 1275-84, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25900228

RESUMO

Familial transmission of chromosome 6 duplications is rare. We report on the first observation of a maternally-inherited pure segmental 6q duplication split into two segments, 6q15q16.3 and 6q16.3q21, and associated with obesity. Obesity has previously been correlated to chromosome 6 q-arm deletion but has not yet been assessed in duplications. The aim of this study was to characterize the structure of these intrachromosomal insertional translocations by classic cytogenetic banding, array-CGH, FISH, M-banding and genotyping using microsatellites and SNP array analysis, in a mother and four offspring. The duplicated 6q segments, 9.75 Mb (dup 1) and 7.05 Mb (dup 2) in size in the mother, were inserted distally into two distinct chromosome 6q regions. They were transmitted to four offspring. A son and a daughter inherited the two unbalanced insertions and displayed, like the mother, an abnormal phenotype with facial dysmorphism, intellectual disability, and morbid obesity. Curiously, two daughters with a normal phenotype inherited only the smaller segment, 6q16.3q21. The abnormal phenotype was associated with the larger proximal 6q15q16.3 duplication. We hypothesize a mechanism for this exceptional phenomenon of recurrent reduction and transmission of the duplication during meiosis in a family. We expect the interpretation of our findings to be useful for genetic counseling and for understanding the mechanisms underlying these large segmental 6q duplications and their evolution.


Assuntos
Padrões de Herança , Deficiência Intelectual/genética , Mutagênese Insercional , Obesidade/genética , Trissomia , Adolescente , Adulto , Criança , Bandeamento Cromossômico , Cromossomos Humanos Par 6 , Hibridização Genômica Comparativa , Família , Feminino , Aconselhamento Genético , Heterogeneidade Genética , Humanos , Deficiência Intelectual/patologia , Masculino , Meiose , Repetições de Microssatélites , Pessoa de Meia-Idade , Obesidade/patologia , Análise de Sequência com Séries de Oligonucleotídeos , Linhagem , Fenótipo
10.
J Hum Genet ; 60(5): 267-71, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25716914

RESUMO

WWOX has been recently implicated in autosomal recessive spinocerebellar ataxia type 12 (SCAR12) and severe early-onset epileptic encephalopathy (EOEE). By array comparative genomic hybridization, we identified a 0.6 Mb homozygous deletion in 16q23.1 in a fetus presenting with brain anomalies. His older sister who died at the age of 22 months from an EOEE was also homozygous for the copy number variations in 16q23.1. This deletion includes the first six exons of WWOX and results in a null genotype in homozygous patients. This family gives additional support for the implication of WWOX in severe EOEEs. We report for the first time prenatal ultrasound findings in a fetus with a WWOX-null genotype. Our study expands the range of brain abnormalities in WWOX-related EOEEs. This additional family confirms the genotype-phenotype correlation with WWOX-null alleles associated with the most severe form of WWOX-related epileptic encephalopathy with premature death.


Assuntos
Encefalopatias/diagnóstico por imagem , Epilepsia/diagnóstico por imagem , Oxirredutases/genética , Proteínas Supressoras de Tumor/genética , Encefalopatias/genética , Hibridização Genômica Comparativa , Epilepsia/genética , Evolução Fatal , Feminino , Genes Recessivos , Estudos de Associação Genética , Humanos , Recém-Nascido , Masculino , Gravidez , Ultrassonografia Pré-Natal , Oxidorredutase com Domínios WW
11.
Br J Haematol ; 169(2): 249-61, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25522886

RESUMO

Relapse after transplantation is a major cause of treatment failure in paediatric acute lymphoblastic leukaemia (ALL). Here, we report the findings of a prospective national study designed to investigate the feasibility of immune intervention in children in first or subsequent remission following myeloablative conditioning. This study included 133 children who received a transplant for ALL between 2005 and 2008. Minimal Residual Disease (MRD) based on T cell receptor/immunoglobulin gene rearrangements was measured on days -30, 30, 90 and 150 post-transplantation. Ciclosporin treatment was rapidly discontinued and donor lymphocyte infusions (DLI) were programmed for patients with a pre- or post-transplant MRD status ≥10(-3) . Only nine patients received DLI. Pre- and post-transplant MRD status, and the duration of ciclosporin were independently associated with 5-year overall survival (OS), which was 62·07% for the whole cohort. OS was substantially higher in patients cleared of MRD than in those with persistent MRD (52·3% vs. 14·3%, respectively). Only pre-transplant MRD status (Hazard Ratio 2·57, P = 0·04) and duration of ciclosporin treatment (P < 0·001) were independently associated with relapse. The kinetics of chimerism were not useful for predicting relapse, whereas MRD monitoring up to 90 d post-transplantation was a valuable prognostic tool to guide therapeutic intervention.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Quimeras de Transplante , Transferência Adotiva , Criança , Feminino , Seguimentos , Doença Enxerto-Hospedeiro/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Linfócitos , Masculino , Neoplasia Residual , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Prognóstico , Modelos de Riscos Proporcionais , Doadores de Tecidos , Resultado do Tratamento
12.
J Med Genet ; 52(1): 61-70, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25411445

RESUMO

BACKGROUND: Homozygous mutations in WWOX were reported in eight individuals of two families with autosomal recessive spinocerebellar ataxia type 12 and in two siblings with infantile epileptic encephalopathy (IEE), including one who deceased prior to DNA sampling. METHODS: By combining array comparative genomic hybridisation, targeted Sanger sequencing and next generation sequencing, we identified five further patients from four families with IEE due to biallelic alterations of WWOX. RESULTS: We identified eight deleterious WWOX alleles consisting in four deletions, a four base-pair frameshifting deletion, one missense and two nonsense mutations. Genotype-phenotype correlation emerges from the seven reported families. The phenotype in four patients carrying two predicted null alleles was characterised by (1) little if any psychomotor acquisitions, poor spontaneous motility and absent eye contact from birth, (2) pharmacoresistant epilepsy starting in the 1st weeks of life, (3) possible retinal degeneration, acquired microcephaly and premature death. This contrasted with the less severe autosomal recessive spinocerebellar ataxia type 12 phenotype due to hypomorphic alleles. In line with this correlation, the phenotype in two siblings carrying a null allele and a missense mutation was intermediate. CONCLUSIONS: Our results obtained by a combination of different molecular techniques undoubtedly incriminate WWOX as a gene for recessive IEE and illustrate the usefulness of high throughput data mining for the identification of genes for rare autosomal recessive disorders. The structure of the WWOX locus encompassing the FRA16D fragile site might explain why constitutive deletions are recurrently reported in genetic databases, suggesting that WWOX-related encephalopathies, although likely rare, may not be exceptional.


Assuntos
Oxirredutases/genética , Fenótipo , Espasmos Infantis/genética , Ataxias Espinocerebelares/genética , Proteínas Supressoras de Tumor/genética , Códon sem Sentido/genética , Hibridização Genômica Comparativa , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Mutação de Sentido Incorreto/genética , Espasmos Infantis/patologia , Ataxias Espinocerebelares/patologia , Oxidorredutase com Domínios WW
13.
Hum Mol Genet ; 24(2): 463-70, 2015 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-25205112

RESUMO

Lichtenstein-Knorr syndrome is an autosomal recessive condition that associates sensorineural hearing loss and cerebellar ataxia. Here, we report the first identification of a gene involved in Lichtenstein-Knorr syndrome. By using a combination of homozygosity mapping and whole-exome sequencing, we identified the homozygous p.Gly305Arg missense mutation in SLC9A1 that segregates with the disease in a large consanguineous family. Mutant glycine 305 is a highly conserved amino acid present in the eighth transmembrane segment of all metazoan orthologues of NHE1, the Na(+)/H(+) exchanger 1, encoded by SLC9A1. We demonstrate that the p.Gly305Arg mutation causes the near complete de-glycosylation, mis-targeting and loss of proton pumping activity of NHE1. The comparison of our family with the phenotypes of spontaneous and knockout Slc9a1 murine models demonstrates that the association between ataxia and hearing loss is caused by complete or near complete loss of function of NHE1 and altered regulation of pHi in the central nervous system.


Assuntos
Proteínas de Transporte de Cátions/genética , Ataxia Cerebelar/genética , Surdez/genética , Displasia Fibrosa Óssea/genética , Síndromes de Imunodeficiência/genética , Mutação de Sentido Incorreto , Neutropenia/genética , Trocadores de Sódio-Hidrogênio/genética , Animais , Proteínas de Transporte de Cátions/metabolismo , Ataxia Cerebelar/metabolismo , Surdez/metabolismo , Facies , Feminino , Displasia Fibrosa Óssea/metabolismo , Humanos , Síndromes de Imunodeficiência/metabolismo , Masculino , Camundongos , Camundongos Knockout , Neutropenia/metabolismo , Trocador 1 de Sódio-Hidrogênio , Trocadores de Sódio-Hidrogênio/metabolismo
14.
Am J Med Genet A ; 164A(10): 2618-22, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24975717

RESUMO

The molecular basis of male disorders of sex development (DSD) remains unexplained in a large number of cases. EMX2 has been proposed to play a role in the masculinization process for the past two decades, but formal evidence for this causal role is scarce. The aim of this study is to yield additional support to this hypothesis by reporting on a male patient who presented with 46,XY DSD, a single kidney, intellectual disability, and the smallest microdeletion including EMX2 reported to date. EMX2 haploinsufficiency is likely to explain the masculinization defect observed in our patient, similar to what has been described in the mouse. In the case of cytogenetically diagnosed cases, deletions of EMX2 have been associated with a wide range of DSD, ranging from hypospadias to complete sex reversal.


Assuntos
Cromossomos Humanos Par 10/genética , Transtornos do Desenvolvimento Sexual/genética , Proteínas de Homeodomínio/genética , Deleção de Sequência/genética , Fatores de Transcrição/genética , Pré-Escolar , Transtorno 46,XY do Desenvolvimento Sexual/genética , Humanos , Masculino , Fenótipo
15.
Mol Cytogenet ; 7: 40, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24963350

RESUMO

BACKGROUND: We report clinical and molecular cytogenetic characterization of a 2 year-old girl with 19p13.2p13.12 microdeletion and compare her clinical features with those of three other patients reported before. RESULT: Array comparative genomic hybridization (aCGH) revealed in the present patient a de novo microdeletion of 1.45 Mb within 19p13.2p13.12. The deletion includes seven OMIM genes: MAN2B1, RNASEH2A, KLF1, GCDH, NFIX, CACNA1A and CC2D1A. DISCUSSION: The present case and three other patients with partially overlapping 19p13 microdeletion share the following features: psychomotor and language delay, intellectual disability, seizures, hypotonia, skeletal anomalies and facial dysmorphism. The smallest region of overlapping between all four reported patients is around 300 kb and spans only two genes: NFIX and CACNA1A. Their haploinsufficincy could be the base for the phenotype -genotype correlation.

16.
Ann Biol Clin (Paris) ; 72(3): 371-7, 2014 May-Jun.
Artigo em Francês | MEDLINE | ID: mdl-24876149

RESUMO

49, XXXXY syndrome is a rare sex chromosome aneuploidy occurring in 1:80 000-1:100 000 male births. Data on this aneuploidy in adulthood are limited, with most of the literature data based on paediatric patients. We report a new male patient whose 49, XXXXY diagnosis was formally made at the age of 54 years. So far, no medical follow-up was performed specifically for his condition. This man presented with facial features (epicanthus, hypertelorism, up-slanting palpebral fissures), microorchidism and features of chronic hypoandrogenism with muscular weakness, sparse body hair, dry skin with abnormal healing of skin wounds. Endocrine evaluation confirmed a hypergonadotropic hypogonadism. He had moderate intellectual deficiency with more affected verbal skills. A recent deep vein thrombosis was diagnosed in his left leg. Unusually, in addition to moderate deafness, he developed progressively a severe vision impairment leading to blindness. There have been very few reports of adult individuals with 49, XXXXY syndrome and this kind of report may contribute to improved management of prospective medical healthcare associated with this condition in older individuals.


Assuntos
Síndrome de Klinefelter/diagnóstico , Aneuploidia , Cegueira/diagnóstico , Surdez/diagnóstico , Pálpebras/anormalidades , Facies , Humanos , Hipertelorismo/diagnóstico , Hipogonadismo/diagnóstico , Deficiência Intelectual/diagnóstico , Síndrome de Klinefelter/genética , Masculino , Pessoa de Meia-Idade
17.
Eur J Hum Genet ; 22(4): 471-9, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24129437

RESUMO

Obesity is a common but highly, clinically, and genetically heterogeneous disease. Deletion of the terminal region of the short arm of chromosome 2 is rare and has been reported in about 13 patients in the literature often associated with a Prader-Willi-like phenotype. We report on five unrelated patients with 2p25 deletion of paternal origin presenting with early-onset obesity, hyperphagia, intellectual deficiency, and behavioural difficulties. Among these patients, three had de novo pure 2pter deletions, one presented with a paternal derivative der(2)t(2;15)(p25.3;q26) with deletion in the 2pter region and the last patient presented with an interstitial 2p25 deletion. The size of the deletions was characterized by SNP array or array-CGH and was confirmed by fluorescence in situ hybridization (FISH) studies. Four patients shared a 2p25.3 deletion with a minimal critical region estimated at 1.97 Mb and encompassing seven genes, namely SH3HYL1, ACP1, TMEMI8, SNTG2, TPO, PXDN, and MYT1L genes. The fifth patient had a smaller interstitial deletion encompassing the TPO, PXDN, and MYT1L genes. Paternal origin of the deletion was determined by genotyping using microsatellite markers. Analysis of the genes encompassed in the deleted region led us to speculate that the ACP1, TMEM18, and/or MYT1L genes might be involved in early-onset obesity. In addition, intellectual deficiency and behavioural troubles can be explained by the heterozygous loss of the SNTG2 and MYT1L genes. Finally, we discuss the parent-of-origin of the deletion.


Assuntos
Cromossomos Humanos Par 2/genética , Proteínas de Membrana/genética , Proteínas do Tecido Nervoso/genética , Obesidade/genética , Proteínas Tirosina Fosfatases/genética , Proteínas Proto-Oncogênicas/genética , Deleção de Sequência , Fatores de Transcrição/genética , Criança , Pré-Escolar , Hibridização Genômica Comparativa , Feminino , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Hibridização in Situ Fluorescente , Masculino , Obesidade/complicações , Obesidade/diagnóstico , Fenótipo , Polimorfismo de Nucleotídeo Único , Síndrome de Prader-Willi/complicações , Síndrome de Prader-Willi/genética , Análise de Sequência de DNA
18.
Eur J Hum Genet ; 22(8): 979-87, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24301060

RESUMO

Fanconi anaemia (FA) is characterized by progressive bone marrow failure, congenital anomalies, and predisposition to malignancy. In a minority of cases, FA results from biallelic FANCD1/BRCA2 mutations that are associated with early-onset leukaemia and solid tumours. Here, we describe the clinical and molecular features of a remarkable family presenting with multiple primary colorectal cancers (CRCs) without detectable mutations in genes involved in the Mendelian predisposition to CRCs. We unexpectedly identified, despite the absence of clinical cardinal features of FA, a biallelic mutation of the FANCD1/BRCA2 corresponding to a frameshift alteration (c.1845_1846delCT, p.Asn615Lysfs*6) and a missense mutation (c.7802A>G, p.Tyr2601Cys). The diagnosis of FA was confirmed by the chromosomal analysis of lymphocytes. Reverse transcriptase (RT)-PCR analysis revealed that the c.7802A>G BRCA2 variation was in fact a splicing mutation that creates an aberrant splicing donor site and results partly into an aberrant transcript encoding a truncated protein (p.Tyr2601Trpfs*46). The atypical FA phenotype observed within this family was probably explained by the residual amount of BRCA2 with the point mutation c.7802A>G in the patients harbouring the biallelic FANCD1/BRCA2 mutations. Although this report is based in a single family, it suggests that CRCs may be part of the tumour spectrum associated with FANCD1/BRCA2 biallelic mutations and that the presence of such mutations should be considered in families with CRCs, even in the absence of cardinal features of FA.


Assuntos
Idade de Início , Alelos , Proteína BRCA2/genética , Neoplasias Colorretais/genética , Mutação , Adulto , Substituição de Aminoácidos , Quebra Cromossômica , Neoplasias Colorretais/diagnóstico , Biologia Computacional , Análise Mutacional de DNA , Feminino , Humanos , Linhagem , Sítios de Splice de RNA , Processamento de RNA
19.
Am J Med Genet A ; 161A(10): 2594-9, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23918747

RESUMO

We report on a 3-year-old girl with a de novo complex X chromosome rearrangement associated with congenital pulmonary alveolar proteinosis (PAP) and short stature. Array comparative genome hybridization and FISH analyses contributed to characterize the complex rearrangement consisting of a 7.37 Mb terminal deletion of Xp22.33p22.2, a 17.3 Mb interstitial inverted duplication of Xp22.2p21.3, and a 10.14 Mb duplication of Xq27.3q28. PCR analysis of microsatellite markers supported a paternal origin of the X chromosome rearrangement. A pre-meiotic two-step mechanism may explain the occurrence of this complex X rearrangement: an inverted duplication deletion event on Xp, and duplication of the Xq27.3qter region through a telomere capture event stabilizing the broken chromosome Xp end. The girl has also inherited from her healthy mother an X chromosome with a colony stimulating factor 2 receptor, alpha (CSF2RA) gene deletion. Consistent with the recessive mode of inheritance, the de novo paternal Xp22.33p22.2 deletion combined to the maternally inherited CSF2RA gene deletion led to homozygous deletion of CSF2RA and PAP diagnosis in the girl. The Xp deletion encompasses the pseudoautosomal region 1 (PAR1) which contains genes that escape X inactivation. Short stature homeobox (SHOX) haploinsufficiency explains growth retardation. Absence of other symptoms in relation to the X deletion/amplification is most probably due to skewed X inactivation. Finally, inherited deletions may unmask rare pathogenic genomic rearrangement and contribute to clinical phenotypes by a recessive mode of gene action.


Assuntos
Aberrações Cromossômicas , Cromossomos Humanos X , Proteinose Alveolar Pulmonar/congênito , Receptores de Fator Estimulador das Colônias de Granulócitos e Macrófagos/genética , Adulto , Pré-Escolar , Deleção Cromossômica , Hibridização Genômica Comparativa , Feminino , Humanos , Hibridização in Situ Fluorescente , Masculino , Proteinose Alveolar Pulmonar/diagnóstico , Proteinose Alveolar Pulmonar/genética , Inativação do Cromossomo X
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