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1.
Hum Genet ; 138(10): 1183-1200, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31471722

RESUMO

The glutamate pyruvate transaminase 2 (GPT2) gene produces a nuclear-encoded mitochondrial enzyme that catalyzes the reversible transfer of an amino group from glutamate to pyruvate, generating alanine and alpha-ketoglutarate. Recessive mutations in GPT2 have been recently identified in a new syndrome involving intellectual and developmental disability (IDD), postnatal microcephaly, and spastic paraplegia. We have identified additional families with recessive GPT2 mutations and expanded the phenotype to include small stature. GPT2 loss-of-function mutations were identified in four families, nine patients total, including: a homozygous mutation in one child [c.775T>C (p.C259R)]; compound heterozygous mutations in two siblings [c.812A>C (p.N271T)/c.1432_1433delGT (p.V478Rfs*73)]; a novel homozygous, putative splicing mutation [c.1035C>T (p.G345=)]; and finally, a recurrent mutation, previously identified in a distinct family [c.1210C>T (p.R404*)]. All patients were diagnosed with IDD. A majority of patients had remarkably small stature throughout development, many < 1st percentile for height and weight. Given the potential biological function of GPT2 in cellular growth, this phenotype is strongly suggestive of a newly identified clinical susceptibility. Further, homozygous GPT2 mutations manifested in at least 2 of 176 families with IDD (approximately 1.1%) in a Pakistani cohort, thereby representing a relatively common cause of recessive IDD in this population, with recurrence of the p.R404* mutation in this population. Based on variants in the ExAC database, we estimated that approximately 1 in 248 individuals are carriers of moderately or severely deleterious variants in GPT2.


Assuntos
Deficiências do Desenvolvimento/diagnóstico , Deficiências do Desenvolvimento/genética , Genes Recessivos , Predisposição Genética para Doença , Mutação , Fenótipo , Transaminases/genética , Adolescente , Alelos , Substituição de Aminoácidos , Deficiências do Desenvolvimento/metabolismo , Ativação Enzimática , Éxons , Feminino , Frequência do Gene , Estudos de Associação Genética , Genética Populacional , Genótipo , Humanos , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/genética , Imagem por Ressonância Magnética , Masculino , Mitocôndrias/genética , Mitocôndrias/metabolismo , Modelos Moleculares , Linhagem , Conformação Proteica , Sítios de Splice de RNA , Análise de Sequência de DNA , Relação Estrutura-Atividade , Transaminases/química , Transaminases/metabolismo
2.
Cytogenet Genome Res ; 158(4): 192-198, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31394532

RESUMO

Prader-Willi syndrome (PWS) and recurrent 15q13.3 microdeletion syndrome can be caused by genomic rearrangements in the complex 15q11q13 chromosomal region. Here, we describe the first female child with PWS and 15q13.3 microdeletion syndrome resulting from an unusual 10.7-Mb deletion from 15pter to 15q13.3 due to an unbalanced de novo 15;19 translocation. The patient presents with hypotonia, microcephaly, developmental delay with lack of speech, intellectual disability, happy demeanor, clinodactyly of the 4th and 5th fingers, and dysmorphic facial features discordant for PWS and consistent with an atypical phenotype.


Assuntos
Transtornos Cromossômicos/complicações , Transtornos Cromossômicos/genética , Deficiência Intelectual/complicações , Deficiência Intelectual/genética , Síndrome de Prader-Willi/complicações , Síndrome de Prader-Willi/genética , Convulsões/complicações , Convulsões/genética , Translocação Genética/genética , Pré-Escolar , Deleção Cromossômica , Cromossomos Humanos Par 15/genética , Feminino , Humanos , Recém-Nascido
3.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 36(8): 829-833, 2019 Aug 10.
Artigo em Chinês | MEDLINE | ID: mdl-31400139

RESUMO

OBJECTIVE: To explore the genetic basis for a family affected with mental retardation combined with autism. METHODS: For the family featuring X-linked recessive inheritance of mental retardation combined with autism, clinical data and peripheral blood samples were collected. Potential mutations of genes associated with intellectual impairment were sequenced with an Ion PGM platform. Suspected mutations were verified with a PCR-Sanger sequencing method. RESULTS: The patient with mental retardation had mild abnormal electroencephalograph(EEG), while brain MRI and CT scans showed no obvious abnormality. Two ABC (autism behavior checklist) testing scores were 73 and 66 when he was 7- and 13-year-old, respectively. A novel hemizygous mutation, c.64C>T (p.L22F), was detected in the GRIA3 gene in the patient, for which his mother was a heterozygous carrier. The mutation site was predicted to be possibly damaging and disease causing by PolyPhen_2 and MutationTaster. CONCLUSION: The novel hemizygous c.64C>T (p.L22F) mutation of the GRIA3 gene probably underlies the phenotypes of mental retardation combined with autism in this family. Considering the variable clinical manifestation of mental retardation and genetic heterogeneity of autism, genetic testing is essential for making the correct diagnosis.


Assuntos
Transtorno Autístico/genética , Deficiência Intelectual/genética , Retardo Mental Ligado ao Cromossomo X/genética , Receptores de AMPA/genética , Adolescente , Criança , Humanos , Masculino , Mutação
4.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 36(8): 837-840, 2019 Aug 10.
Artigo em Chinês | MEDLINE | ID: mdl-31400141

RESUMO

OBJECTIVE: To analyze the clinical and molecular genetic characteristics of patient with Kleefstra syndrome 1. METHODS: Clinical data, chromosomal karyotype and whole genome copy number variations (CNVs) of the patient were analyzed. RESULTS: The patient was found to have a karyotype of 45,XX,-9[4]/46,XX,r(9)(p24q34)[56]. Whole-genome CNVs detection revealed that she has carried a heterozygous deletion of approximately 670 kb at 9q34.3, which encompassed the entire EHMT1 gene. The region is strongly associated with Kleefstra syndrome (1/9q telomere deletion). In addition, the patient also had heterozygous deletion of 9pter, which may predispose to formation of ring chromosome 9. CONCLUSION: The child was diagnosed with Kleefstra syndrome type 1 in conjunct with ring chromosome 9.


Assuntos
Cromossomos Humanos Par 9/genética , Anormalidades Craniofaciais/genética , Cardiopatias Congênitas/genética , Deficiência Intelectual/genética , Cromossomos em Anel , Criança , Deleção Cromossômica , Variações do Número de Cópias de DNA , Feminino , Humanos
5.
Artigo em Russo | MEDLINE | ID: mdl-31317896

RESUMO

AIM: Long continuous stretches of homozygosity (LCSH) are regularly detected in studies using molecular karyotyping (SNP array). Despite this type of variation being able to provide meaningful data on the parents' kinship, uniparental disomy and chromosome rearrangements, LCSH are rarely considered as a possible epigenetic cause of neurodevelopmental disorders. Despite their direct relationship to imprinting, LCSH in imprinted loci have not been considered in terms of pathogenicity. The present work is aimed at studying LCSH in chromosomal regions containing imprinted genes previously associated with disease in children with idiopathic intellectual disability, autism, congenital malformations and/or epilepsy. MATERIAL AND METHODS: Five hundred and four patients with autism spectrum disorders and intellectual disability were examined. RESULTS: LCSH affecting imprinted loci associated with various diseases were identified in 40 (7.9%) individuals. Chromosomal region 7q21.3 was affected in twenty three cases, 15q11.2 in twelve, 11p15.5 in five, 7q32.2 in four. Four patients had 2 LCSH affecting imprinted loci. Besides one LCSH in 7q31.33q32.3 (~4 Mbp) region, all LCSH were 1-1.6 Mbp. Clinically, these cases resembled the corresponding imprinting diseases (e.g. Silver-Russell, Beckwith-Wiedemann, Prader-Willi, Angelman syndromes). Parental kinship was identified in 8 cases (1.59%), which were not affected by LCSH at imprinted loci. CONCLUSION: The present study shows that LCSH affecting chromosomal regions 7q21.3, 7q32.2, 11p15.5 and 15p11.2 occur in about 7.9% of children with intellectual disability, autism, congenital malformations and/or epilepsy. Consequently, this type of epigenetic mutations is obviously common in a group of children with neurodevelopmental disorders. LCSH less than 2.5-10 Mbp are usually ignored in molecular karyotyping (SNP array) studies and, therefore, an important epigenetic cause of intellectual disability, autism or epilepsy with high probability remains without attention.


Assuntos
Síndrome de Angelman , Transtorno do Espectro Autista , Epigenômica , Deficiência Intelectual , Síndrome de Angelman/genética , Transtorno do Espectro Autista/genética , Criança , Humanos , Deficiência Intelectual/genética , Perda de Heterozigosidade
6.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 36(7): 672-675, 2019 Jul 10.
Artigo em Chinês | MEDLINE | ID: mdl-31302908

RESUMO

OBJECTIVE: To explore the genetic basis for three patients with development delay and to correlate their clinical phenotypes with genetic findings. METHODS: The karyotypes of the probands and their parents were analyzed by conventional G-banding. Chromosomal microarray analysis (CMA) was used to detect microdeletion and microduplication. RESULTS: No kartotypic abnormality was detected in the patients and their parents. CMA analysis identified a de novo 3.10 Mb deletion on chromosome 15q24.1q24.2 in case 1, a de novo 3.14 Mb deletion at 15q24.1q24.2 in case 2, and a 3.13 Mb deletion at 15q24.1q24.2 in case 3. All deletions have encompassed the CPLX3,SEMA7A and SIN3A genes. CONCLUSION: The three patients were diagnosed with 15q24 microdeletion syndrome. CPLX3,SEMA7A and SIN3A may be the key genes responsible for this syndrome.


Assuntos
Transtornos Cromossômicos/genética , Deficiência Intelectual/genética , Proteínas Adaptadoras de Transdução de Sinal/genética , Antígenos CD/genética , Criança , Deleção Cromossômica , Cromossomos Humanos Par 15/genética , Proteínas Ligadas por GPI/genética , Humanos , Proteínas Repressoras/genética , Semaforinas/genética
7.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 36(7): 704-707, 2019 Jul 10.
Artigo em Chinês | MEDLINE | ID: mdl-31302916

RESUMO

OBJECTIVE: To explore the genetic basis of a child featuring intellectual disability, developmental delay and epilepsy. METHODS: Cytogenetic and molecular analysis including chromosomal karyotyping analysis, single nucleotide polymorphism array (SNP array) and qPCR were performed. RESULTS: The karyotype of the child was determined as 46, XX; SNP array: arr [19]21q22.12q22.13(36 860 195-38 801 482)×1 dn. A heterozygous 1.9 Mb microdeletion was detected at 21q22.12q22.13. qPCR has confirmed deletion of exon 1 of the DYRK1A gene, which has occurred de novo. CONCLUSION: A 21q22 deletion was diagnosed with multiple genetic methods. Genotype-phenotype correlation suggested DYRK1A to be a candidate for intellectual disability.


Assuntos
Deficiências do Desenvolvimento/genética , Epilepsia/genética , Deficiência Intelectual/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Tirosina Quinases/genética , Deleção de Sequência , Criança , Estudos de Associação Genética , Humanos , Cariotipagem
8.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 36(7): 712-715, 2019 Jul 10.
Artigo em Chinês | MEDLINE | ID: mdl-31302918

RESUMO

OBJECTIVE: To analyze the clinical characteristics and genetic basis of a child affected with Glass syndrome. METHODS: Clinical manifestations and auxiliary examination results of the child were analyzed. Potential mutation was detected with next generation sequencing and validated by Sanger sequencing. RESULTS: The child has featured growth and mental retardation, delayed speech, cleft palate, crowding of teeth, and downslanting palpebral fissures. DNA sequencing revealed a de novo heterozygous missense mutation c.1166G>A (p.R389H) in exon 8 of the SATB2 gene in the child. CONCLUSION: The heterozygous mutation c.1166G>A (p.R389H) of the SATB2 gene probably account for the Glass syndrome in the patient.


Assuntos
Anormalidades Múltiplas/genética , Deficiência Intelectual/genética , Proteínas de Ligação à Região de Interação com a Matriz/genética , Fatores de Transcrição/genética , Criança , Deleção Cromossômica , Cromossomos Humanos Par 2 , Humanos , Mutação
9.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 36(7): 716-719, 2019 Jul 10.
Artigo em Chinês | MEDLINE | ID: mdl-31302919

RESUMO

OBJECTIVE: To report on a child with mental retardation caused by SYNGAP1 gene mutation. METHODS: Peripheral blood samples were collected from the proband and her parents. High throughput sequencing (HTS) was employed for screening for potential mutation in the patient. Suspected mutation was validated by Sanger sequencing of the child and her parents. RESULTS: By HTS, a previously unknown mutation [c.1656C>A (p.C552*)] was found in exon 10 of the SYNGAP1 gene in the proband. Sanger sequencing confirmed the heterozygous nature of the mutation and that neither of her parents carried the same mutation. CONCLUSION: The dysmorphism and developmental delay of the child were probably due to the pathogenic mutation of the SYNGAP1 gene. HTS can facilitate elucidation of the genetic etiology with efficiency, which has great significance in the diagnosis, treatment and prognosis of the child.


Assuntos
Deficiência Intelectual/genética , Proteínas Ativadoras de ras GTPase/genética , Criança , Éxons , Feminino , Heterozigoto , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Mutação
10.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 36(7): 727-730, 2019 Jul 10.
Artigo em Chinês | MEDLINE | ID: mdl-31302922

RESUMO

OBJECTIVE: To analyze the clinical and molecular genetics features of a family affected with Say-Barber-Biesecker-Young-Simpson syndrome (SBBYSS). METHODS: High-throughput sequencing was used to detect copy number variations (CNVs) and pathogenic variant within the whole exome of the affected child. RESULTS: No pathogenic CNV was found in the child, while exome sequencing identified a heterozygous c.3367_c.3370delAGAA (p.Arg1123Argfs*6) frameshifting variant in the exon 16 of the KAT6B gene. The same variant was not found in either parent. CONCLUSION: The c.3367_c.3370delAGAA (p.R1123Rfs*6) probably underlies the disease in the affected child. Above finding has facilitated genetic counseling and prenatal diagnosis for the family.


Assuntos
Blefarofimose/genética , Hipotireoidismo Congênito/genética , Variações do Número de Cópias de DNA , Cardiopatias Congênitas/genética , Histona Acetiltransferases/genética , Deficiência Intelectual/genética , Instabilidade Articular/genética , Criança , Facies , Feminino , Humanos , Mutação , Fenótipo , Gravidez
11.
Klin Padiatr ; 231(5): 233-239, 2019 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-31340405

RESUMO

BACKGROUND: Shared decision-making is indispensable when it comes to molecular genetic investigations, but data on the expectations of the parents is scarce. METHODS: Using a step-by-step approach we initially performed free in-depth-interviews with five parents on which base we developed a half standardized questionnaire. This questionnaire was then applied in interviews with 30 parents of children with intellectual disability, autism or epilepsy subject to genetic examination. RESULTS: Pre-diagnostic discussions are challenging for the parents in an intellectual as well as emotional way. The most important general aspects are diagnosis and therapy. Self-assessment of prior knowledge is very variable and many parents expressed problems in understanding. During the conversation parents rate the following specific aspects as "very important" or "important": findings of unclear relevance, incidental findings, psychic consequences, prognostic aspects, possible therapeutic interventions. 10 Parents did not have any school-degree and 20 parents were not native speakers. DISCUSSION: All parents express a high need for information covering almost all aspects of the investigation. Communicational hurdles pose additional challenges leaving a large room for improvement. Trustworthy internet-based information systems in different languages including plain language could be a first step.


Assuntos
Deficiências do Desenvolvimento/genética , Epilepsia/genética , Deficiência Intelectual/genética , Pais/psicologia , Criança , Humanos , Inquéritos e Questionários
12.
Hum Genet ; 138(10): 1145-1153, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31321490

RESUMO

The objective of this study is to shed light on the phenotype and inheritance pattern of rare 13q33-q34 microdeletions. Appropriate cases were retrieved using local databases of two largest Israeli centers performing CMA analysis. In addition, literature search in PubMed, DECIPHER and ClinVar databases was performed. Local database search yielded eight new patients with 13q33.1-q34 microdeletions (three of which had additional copy number variants). Combined with 15 cases detected by literature search, an additional 23 cases were reported in DECIPHER database, and 17 cases from ClinVar, so overall 60 patients with isolated 13q33.1-q34 microdeletions were described. Developmental delay and/or intellectual disability were noted in the vast majority of affected individuals (81.7% = 49/60). Of the 23 deletions involving the 13q34 cytoband only, in 3 cases, developmental delay and/or intellectual disability was not reported. Interestingly, in two of these cases (66.7%), the deletions did not involve the terminal CHAMP1 gene, as opposed to 3/20 (15%) of patients with 13q34 deletions and neurocognitive disability. Facial dysmorphism and microcephaly were reported in about half of the overall cases, convulsions were noted in one-fifth of the patients, while heart anomalies, short stature and hypotonia each involved about 10-30% of the cases. None of the 13q33-q34 deletions were inherited from a reported healthy parent. 13q33-q34 microdeletions are rare chromosomal aberrations, associated with high risk for neurodevelopmental disability. The rarity of this chromosomal aberration necessitates continuous reporting and collection of available evidence, to improve the ability to provide accurate genetic counseling, especially in the context of prenatal setting.


Assuntos
Deleção Cromossômica , Transtornos Cromossômicos/diagnóstico , Transtornos Cromossômicos/genética , Cromossomos Humanos Par 13 , Fenótipo , Adolescente , Adulto , Criança , Pré-Escolar , Bandeamento Cromossômico , Deficiências do Desenvolvimento/diagnóstico , Deficiências do Desenvolvimento/genética , Feminino , Humanos , Lactente , Recém-Nascido , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/genética , Masculino , Adulto Jovem
13.
BMC Med Genet ; 20(1): 101, 2019 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-31174490

RESUMO

BACKGROUND: N-terminal acetylation is a common protein modification in human cells and is catalysed by N-terminal acetyltransferases (NATs), mostly cotranslationally. The NAA10-NAA15 (NatA) protein complex is the major NAT, responsible for acetylating ~ 40% of human proteins. Recently, NAA10 germline variants were found in patients with the X-linked lethal Ogden syndrome, and in other familial or de novo cases with variable degrees of developmental delay, intellectual disability (ID) and cardiac anomalies. METHODS: Here we report a novel NAA10 (NM_003491.3) c.248G > A, p.(R83H) missense variant in NAA10 which was detected by whole exome sequencing in two unrelated boys with intellectual disability, developmental delay, ADHD like behaviour, very limited speech and cardiac abnormalities. We employ in vitro acetylation assays to functionally test the impact of this variant on NAA10 enzyme activity. RESULTS: Functional characterization of NAA10-R83H by in vitro acetylation assays revealed a reduced enzymatic activity of monomeric NAA10-R83H. This variant is modelled to have an altered charge density in the acetyl-coenzyme A (Ac-CoA) binding region of NAA10. CONCLUSIONS: We show that NAA10-R83H has a reduced monomeric catalytic activity, likely due to impaired enzyme-Ac-CoA binding. Our data support a model where reduced NAA10 and/or NatA activity cause the phenotypes observed in the two patients.


Assuntos
Acetiltransferases/genética , Deficiência Intelectual/genética , Microcefalia/genética , Mutação de Sentido Incorreto , Acetiltransferase N-Terminal A/genética , Acetiltransferase N-Terminal E/genética , Acetilação , Acetiltransferases/metabolismo , Sequência de Aminoácidos , Pré-Escolar , Humanos , Lactente , Masculino , Modelos Moleculares , Acetiltransferase N-Terminal A/química , Acetiltransferase N-Terminal A/metabolismo , Acetiltransferase N-Terminal E/química , Acetiltransferase N-Terminal E/metabolismo , Fenótipo , Domínios Proteicos , Homologia de Sequência de Aminoácidos , Sequenciamento Completo do Exoma
14.
Gene ; 706: 162-171, 2019 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-31085274

RESUMO

In clinical genetics, the need to discriminate between benign and pathogenic variants identified in patients with neurodevelopmental disorders is an absolute necessity. Copy number variants (CNVs) of small size can enable the identification of genes that are critical for neurologic development. However, assigning a definite association with a specific disorder is a difficult task. Among 328 trios analyzed over seven years of activity in a single laboratory, we identified 19 unrelated patients (5.8%) who carried a small (<500 kb) de novo CNV. Four patients had an additional independent de novo CNV. Nine had a variant that could be assigned as definitely pathogenic, whereas the remaining CNVs were considered as variants of unknown significance (VUS). We report clinical and molecular findings of patients harboring VUS. We reviewed the medical literature available for genes impacted by CNVs, obtained the probability of truncating loss-of-function intolerance, and compared overlapping CNVs reported in databases. The classification of small non-recurrent CNVs remains difficult but, among our findings, we provide support for a role of SND1 in the susceptibility of autism, describe a new case of the rare 17p13.1 microduplication syndrome, and report an X-linked duplication involving KIF4A and DLG3 as a likely cause of epilepsy.


Assuntos
Variações do Número de Cópias de DNA/genética , Transtornos do Neurodesenvolvimento/genética , Adulto , Transtorno Autístico/genética , Criança , Pré-Escolar , Epilepsia/genética , Feminino , Humanos , Lactente , Deficiência Intelectual/genética , Cinesina/genética , Masculino , Proteínas Nucleares/genética , Proteínas Nucleares/fisiologia , Fatores de Transcrição/genética
15.
Cytogenet Genome Res ; 158(1): 25-31, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31055587

RESUMO

Diagnosing a complex genetic syndrome and correctly assigning the concomitant phenotypic traits to a well-defined clinical form is often a medical challenge. In this work, we report the analysis of a family with complex phenotypes, including microcephaly, intellectual disability, dysmorphic features, and polydactyly in the proband, with the aim of adding new aspects for obtaining a clear diagnosis. We performed array-comparative genomic hybridization and quantitative reverse transcriptase PCR (qRT-PCR) analyses. We identified a deletion of chromosome 20p12.1 involving the macrodomain containing 2/mono-ADP ribosylhydrolase 2 gene (MACROD2) in several members of the family. This gene is actually not associated with a specific syndrome but with congenital anomalies of multiple organs. qRT-PCR showed higher levels of a MACROD2 mRNA isoform in the individuals carrying the deletion. Our results, together with other data reported in the literature, support the hypothesis that the deletion in MACROD2 can affect correct embryonic development and that the presence of another associated event, such as epigenetic modifications at the MACROD2 locus, can influence the level of severity of the pathology.


Assuntos
Anormalidades Múltiplas/genética , Enzimas Reparadoras do DNA/genética , Hidrolases/genética , Deficiência Intelectual/genética , Rim/anormalidades , Microcefalia/genética , Pâncreas/anormalidades , Polidactilia/genética , Deleção de Sequência , Adulto , Cromossomos Humanos Par 20/genética , Cromossomos Humanos Par 20/ultraestrutura , Hibridização Genômica Comparativa , Enzimas Reparadoras do DNA/deficiência , Enzimas Reparadoras do DNA/fisiologia , Desenvolvimento Embrionário/genética , Feminino , Humanos , Hidrolases/deficiência , Hidrolases/fisiologia , Masculino , Linhagem , Fenótipo , Transtornos Psicomotores/genética
16.
BMC Cancer ; 19(1): 435, 2019 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-31077186

RESUMO

BACKGROUND: Several subunits of the SWI/SNF chromatin remodeling complex are implicated in both cancer and neurodevelopmental disorders (NDD). Though there is no clinical evidence for an increased tumor risk in individuals with NDDs due to germline mutations in most of these genes so far, this has been repeatedly proposed and discussed. A young woman with NDD due to a de novo mutation in ARID1B now presented with a large renal (> 19 cm in diameter) and multiple hepatic angiomyolipomas (AMLs) but no other signs of tuberous sclerosis complex. METHODS: We analyzed tumor and healthy tissue samples with exome and panel sequencing. RESULTS: Additionally to the previously known, germline ARID1B variant we identified a post-zygotic truncating TSC2 variant in both renal and hepatic AMLs but not in any of the healthy tissues. We did not detect any further, obvious tumor driver events. The identification of a passenger variant in SIPA1L3 in both AMLs points to a common clonal origin. Metastasis of the renal AML into the liver is unlikely on the basis of discordant histopathological features. Our findings therefore point to very low-grade mosaicism for the TSC2 variant, possibly in a yet unknown mesenchymal precursor cell that expanded clonally during tumor development. A possible contribution of the germline ARID1B variant to the tumorigenesis remains unclear but cannot be excluded given the absence of any other evident tumor drivers in the AMLs. CONCLUSION: This unique case highlights the blurred line between tumor genetics and post-zygotic events that can complicate exact molecular diagnoses in patients with rare manifestations. It also demonstrates the relevance of multiple disorders in a single individual, the challenges of detecting low-grade mosaicisms, and the importance of proper diagnosis for treatment and surveillance.


Assuntos
Angiomiolipoma/genética , Deficiência Intelectual/complicações , Neoplasias Renais/genética , Neoplasias Hepáticas/genética , Proteína 2 do Complexo Esclerose Tuberosa/genética , Proteínas de Ligação a DNA/genética , Feminino , Mutação em Linhagem Germinativa , Humanos , Deficiência Intelectual/genética , Mosaicismo , Fatores de Transcrição/genética , Sequenciamento Completo do Exoma , Adulto Jovem
17.
BMC Med Genet ; 20(1): 80, 2019 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-31088393

RESUMO

BACKGROUND: Intellectual disability/developmental delay is a complex condition with extraordinary heterogeneity. A large proportion of patients lacks a specific diagnosis. Next generation sequencing, enabling identification of genetic variations in multiple genes, has become an efficient strategy for genetic analysis in intellectual disability/developmental delay. METHODS: Clinical data of 112 Chinese families with unexplained intellectual disability/developmental delay was collected. Targeted next generation sequencing of 454 genes related to intellectual disability/developmental delay was performed for all 112 index patients. Patients with promising variants and their other family members underwent Sanger sequencing to validate the authenticity and segregation of the variants. RESULTS: Fourteen promising variants in genes EFNB1, MECP2, ATRX, NAA10, ANKRD11, DHCR7, LAMA1, NFIX, UBE3A, ARID1B and PTPRD were identified in 11 of 112 patients (11/112, 9.82%). Of 14 variants, eight arose de novo, and 13 are novel. Nine patients (9/112, 8.03%) got definite molecular diagnoses. It is the first time to report variants in EFNB1, NAA10, DHCR7, LAMA1 and NFIX in Chinese intellectual disability/developmental delay patients and first report about variants in NAA10 and LAMA1 in affected individuals of Asian ancestry. CONCLUSIONS: Targeted next generation sequencing of 454 genes is an effective test strategy for patients with unexplained intellectual disability/developmental delay. Genetic heterogenicity is significant in this Chinese cohort and de novo variants play an important role in the diagnosis. Findings of this study further delineate the corresponding phenotypes, expand the mutation spectrum and support the involvement of PTPRD in the disease.


Assuntos
Deficiências do Desenvolvimento/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Deficiência Intelectual/genética , Mutação , Adolescente , Criança , Pré-Escolar , China , Cromossomos Humanos X , Feminino , Genes Dominantes , Genes Recessivos , Heterogeneidade Genética , Humanos , Lactente , Masculino , Linhagem , Fenótipo
18.
Cytogenet Genome Res ; 157(3): 141-147, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30947196

RESUMO

Chromosomal microarray (CMA) is currently considered as a first-tier test in the genetic assessment of patients presenting with intellectual disability and/or multiple congenital abnormalities. The distinction between pathogenic CNVs, polymorphisms, and variants of unknown significance can be a diagnostic dilemma for cytogeneticists. The size of the CNV has been proposed as a useful criterion. We herein report the characterization of a 13.6-Mb interstitial duplication 20p11.1p12.1, found in a child presenting with mild global developmental delay, by standard karyotype and CMA. Unexpectedly, the same CNV was detected in the patient's mother and pregnant sister, who were healthy. On the basis of these results, an implication of this CNV in the neurological problems observed in the proband was considered to be unlikely. This report underlines the complexity of genetic counseling concerning rare chromosomal abnormalities, when little information is available either in the literature or in international cytogenetic databases.


Assuntos
Duplicação Cromossômica , Coloração Cromossômica/métodos , Anormalidades Congênitas/genética , Deficiência Intelectual/genética , Criança , Variações do Número de Cópias de DNA , Feminino , Aconselhamento Genético , Humanos , Masculino , Mães , Linhagem , Irmãos
19.
Cytogenet Genome Res ; 157(4): 220-226, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30939474

RESUMO

Trisomy 18p is a rarely observed chromosomal aberration. Only 31 cases have previously been described in the literature. Trisomy 18p is associated with mild to moderate phenotypic anomalies and intellectual disability. Here, we report on a pregnant woman in whom noninvasive prenatal testing indicated a high risk of fetal trisomy 18. Prenatal diagnosis and karyotyping of the parents were performed and demonstrated that both the mother and the fetus had a derivative chromosome 15 with a segment of unknown origin. Chromosomal microarray analysis and FISH revealed a 14.9-Mb duplication of 18p and detected 3 centromeres of chromosome 18. To our knowledge, this is the first study reporting trisomy 18p due to an unbalanced translocation of 18p onto chromosome 15q showing 2-generation transmission. The results suggest that trisomy 18p can be considered a euchromatic variant.


Assuntos
Cromossomos Humanos Par 15/genética , Deficiência Intelectual/genética , Diagnóstico Pré-Natal/métodos , Trissomia/genética , Cromossomos Humanos Par 18/genética , Feminino , Humanos , Hibridização in Situ Fluorescente , Análise de Sequência com Séries de Oligonucleotídeos , Gravidez , Translocação Genética , Adulto Jovem
20.
J Genet ; 982019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30945684

RESUMO

Microduplications of the X chromosome are a rare cause of X-linked intellectual disability (XLID), a clinically and genetically heterogeneous spectrum of disorders. In the present study, a 950-kb Xp22.12 microduplication including the RPS6KA3 gene was detected in affected members of a family, including the proband (male), his mother and one maternal uncle. Four female carriers had major depression and one of them also had mild intellectual disability. The present and previous cases with overlapping microduplications suggest that Xp22.12 microduplications can be included in the neuropsychiatric copy number variations.


Assuntos
Cromossomos Humanos X/genética , Doenças Genéticas Ligadas ao Cromossomo X/genética , Deficiência Intelectual/genética , Proteínas Quinases S6 Ribossômicas 90-kDa/genética , Esquizofrenia/genética , Adulto , Duplicação Cromossômica , Variações do Número de Cópias de DNA , Feminino , Doenças Genéticas Ligadas ao Cromossomo X/diagnóstico , Humanos , Deficiência Intelectual/diagnóstico , Masculino , Pessoa de Meia-Idade , Linhagem , Esquizofrenia/diagnóstico
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