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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.
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
3.
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
4.
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
5.
Nat Commun ; 10(1): 2373, 2019 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-31147538

RESUMO

We aimed to develop an efficient, flexible and scalable approach to diagnostic genome-wide sequence analysis of genetically heterogeneous clinical presentations. Here we present G2P ( www.ebi.ac.uk/gene2phenotype ) as an online system to establish, curate and distribute datasets for diagnostic variant filtering via association of allelic requirement and mutational consequence at a defined locus with phenotypic terms, confidence level and evidence links. An extension to Ensembl Variant Effect Predictor (VEP), VEP-G2P was used to filter both disease-associated and control whole exome sequence (WES) with Developmental Disorders G2P (G2PDD; 2044 entries). VEP-G2PDD shows a sensitivity/precision of 97.3%/33% for de novo and 81.6%/22.7% for inherited pathogenic genotypes respectively. Many of the missing genotypes are likely false-positive pathogenic assignments. The expected number and discriminative features of background genotypes are defined using control WES. Using only human genetic data VEP-G2P performs well compared to other freely-available diagnostic systems and future phenotypic matching capabilities should further enhance performance.


Assuntos
Deficiências do Desenvolvimento/genética , Testes Genéticos , Genoma Humano , Sequenciamento Completo do Exoma , Alelos , Genótipo , Humanos , Técnicas de Diagnóstico Molecular , Mutação , Fenótipo , Análise de Sequência de DNA , Sequenciamento Completo do Genoma
6.
Cytogenet Genome Res ; 158(2): 74-82, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31141803

RESUMO

Deletion of distal 9p is associated with a rare clinical condition characterized by dysmorphic features, developmental delay, and ambiguous genitalia. The phenotype shows variable expressivity and is related to the size of the deletion. 8q24 duplication has been reported in only few cases to date, all showing dysmorphic features and mild psychomotor developmental delay. A case of chromosomal aberration involving a 9p terminal deletion with an 8q duplication has never been reported. Here, we describe a child with a female phenotype, male karyotype, dysmorphic features, ambiguous genitalia, and developmental delay. In order to assess the cause of the patient's phenotype, conventional karyotyping, FISH, and a chromosomal microarray analysis were performed on the patient and her parents. The cytogenetic and molecular analysis revealed an unbalanced chromosomal aberration with a duplication in the long arm of chromosome 8 at 8q24.11q24.3 associated with a distal deletion in the short arm of chromosome 9 at 9p24.3p24.1, derived from a maternal balanced translocation. We compared the clinical picture of our patient with other similar cases reported in the literature and found that some clinical findings, such as strabismus, symphalangism of the first finger, and cubitus valgus, have never been previously associated with 9p deletion or 8q duplication expanding the phenotypic range of this condition. This study is aimed to better define the clinical history and prognosis of patients with this rare chromosomal aberration.


Assuntos
Cromossomos Humanos Par 9/genética , Deficiências do Desenvolvimento/genética , Disgenesia Gonadal 46 XY/genética , Trissomia/genética , Deleção Cromossômica , Mapeamento Cromossômico , Cromossomos Humanos Par 8/genética , Feminino , Humanos
7.
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
8.
BMC Med Genet ; 20(1): 88, 2019 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-31117962

RESUMO

BACKGROUND: Succinic semialdehyde dehydrogenase (SSADH) deficiency is a rare autosomal recessively-inherited defect of γ-aminobutyric acid (GABA) metabolism. The absence of SSADH, which is encoded by aldehyde dehydrogenase family 5 member A1 (ALDH5A1) gene, leads to the accumulation of GABA and γ-hydroxybutyric acid (GHB). Few cases with SSADH deficiency were reported in China. CASE PRESENTATION: In this study, four Chinese patients were diagnosed with SSADH deficiency in Tianjin Children's Hospital. We conducted a multidimensional analysis with magnetic resonance imaging (MRI) of the head, semi quantitative detection of urine organic acid using gas chromatography-mass spectrometry, and analysis of ALDH5A1 gene mutations. Two of the patients were admitted to the hospital due to convulsions, and all patients were associated with developmental delay. Cerebral MRI showed symmetrical hyperintense signal of bilateral globus pallidus and basal ganglia in patient 1; hyperintensity of bilateral frontal-parietal lobe, widened ventricle and sulci in patient 2; and widened ventricle and sulci in patient 4. Electroencephalogram (EEG) revealed the background activity of epilepsy in patient 1 and the disappearance of sleep spindle in patient 2. Urine organic acid analysis revealed elevated GHB in all the patients. Mutational analysis, which was performed by sequencing the 10 exons and flanking the intronic regions of ALDH5A1 gene for all the patients, revealed mutations at five sites. Two cases had homozygous mutations with c.1529C > T and c.800 T > G respectively, whereas the remaining two had different compound heterozygous mutations including c.527G > A/c.691G > A and c.1344-2delA/c.1529C > T. Although these four mutations have been described previously, the homozygous mutation of c.800 T > G in ALDH5A1 gene is a novel discovery. CONCLUSION: SSADH deficiency is diagnosed based on the elevated GHB and 4, 5DHHA by urinary organic acid analysis. We describe a novel mutation p.V267G (c.800 T > G) located in the NAD binding domain, which is possibly crucial for this disease's severity. Our study expands the mutation spectrum of ALDH5A1 and highlights the importance of molecular genetic evaluation in patients with SSADH deficiency.


Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/genética , Análise Mutacional de DNA/métodos , Deficiências do Desenvolvimento/genética , Mutação , Succinato-Semialdeído Desidrogenase/deficiência , Succinato-Semialdeído Desidrogenase/genética , Erros Inatos do Metabolismo dos Aminoácidos/diagnóstico por imagem , Erros Inatos do Metabolismo dos Aminoácidos/etnologia , Grupo com Ancestrais do Continente Asiático/genética , Pré-Escolar , China , Deficiências do Desenvolvimento/diagnóstico por imagem , Deficiências do Desenvolvimento/etnologia , Feminino , Humanos , Lactente , Imagem por Ressonância Magnética/métodos , Masculino , Succinato-Semialdeído Desidrogenase/metabolismo
9.
Gene ; 704: 97-102, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-30978478

RESUMO

In the current study, we report three cases of Asparagine Synthetase (ASNS) Deficiency from two consanguineous families. Family 1 had two early neonatal deaths due to a novel mutation in the ASNS gene c.788C > T (p.S263F) and both the children presented with microcephaly and one of them had severe intracranial haemorrhage. The proband from the second family was homozygous for c.146G > A (p.R49Q) and manifested myoclonic seizures, developmental delay, coarse hair and diffuse cortical atrophy. Molecular docking studies of both the mutations revealed alteration in the ligand binding site. Till date, 26 mutations were reported in ASNS gene in 29 affected children indicating high degree of genetic heterogeneity and high mortality. Although asparagine depletion is not of diagnostic utility, multiple linear regression model suggested that asparagine levels vary to the extent of 20.6% based on glutamine and aspartate levels and ASNS deficiency results in depletion of asparagine synthesis. ASNS deficiency should be suspected in any neonate with microcephaly and epileptic encephalopathy.


Assuntos
Carbono-Nitrogênio Ligases com Glutamina como Doadora de N-Amida/genética , Deficiências do Desenvolvimento/genética , Microcefalia/genética , Anormalidades Múltiplas/genética , Anormalidades Múltiplas/patologia , Grupo com Ancestrais do Continente Asiático , Carbono-Nitrogênio Ligases com Glutamina como Doadora de N-Amida/deficiência , Pré-Escolar , Consanguinidade , Análise Mutacional de DNA , Deficiências do Desenvolvimento/complicações , Deficiências do Desenvolvimento/patologia , Família , Feminino , Humanos , Índia , Lactente , Recém-Nascido , Hemorragias Intracranianas/congênito , Hemorragias Intracranianas/genética , Masculino , Microcefalia/patologia , Técnicas de Diagnóstico Molecular , Morte Perinatal , Convulsões/complicações , Convulsões/genética
10.
Medicine (Baltimore) ; 98(15): e15146, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30985688

RESUMO

To characterize the etiology underlying a novel case of global developmental delay syndrome (GDDS) identified in a female child, aged 3 years old. This syndrome is a common pediatric presentation estimated to affect 3.65% of children aged 3 to 17 years.The proband's detailed family history was used to infer a likely mode of inheritance for the GDDS. Genomic DNA samples collected from the proband and her parents were evaluated using conventional karyotyping, multiplex ligation-dependent probe amplification (MLPA), comparative genomic hybridization microarray (aCGH), and fluorescent in situ hybridization (FISH) analysis techniques.An analysis of the proband's family history suggested that she inherited the GDDS from her father. The conducted conventional karyotyping and MLPA methods failed to identify a causative defect for the GDDS; however, the aCGH analysis revealed both a 6.6-Mb deletion at p14-p15.3 of chromosome 10 (arr[hg19]; 100,026-6,710,183), and a 6.3-Mb duplication at p11.31-p11.32 of chromosome 18 (arr[hg19]; 136,226-6,406,733) in the proband. The conducted FISH analysis subsequently determined that these mutations resulted from a balanced translocation t(10;18)(p15.3; p11.32) carried by the proband's father. Finally, a bioinformatic analysis of the proband's mutations revealed ZMYND11 as a promising candidate causative gene for this case of GDDS.The present study demonstrates that the aCGH method can be used to effectively identify the location and approximate size of microdeletions and/or microduplications, but not balanced reciprocal translocations. The nonconventional analysis methods used in the present study may be applicable to other GDDS cases with elusive etiology, and likewise, ZMYND11 should be considered as a potential causative gene during the investigation of future GDDS cases.


Assuntos
Proteínas de Transporte/genética , Deleção Cromossômica , Duplicação Cromossômica , Deficiências do Desenvolvimento/genética , Pré-Escolar , Família , Feminino , Humanos
11.
N Engl J Med ; 380(15): 1433-1441, 2019 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-30970188

RESUMO

We report an inborn error of metabolism caused by an expansion of a GCA-repeat tract in the 5' untranslated region of the gene encoding glutaminase (GLS) that was identified through detailed clinical and biochemical phenotyping, combined with whole-genome sequencing. The expansion was observed in three unrelated patients who presented with an early-onset delay in overall development, progressive ataxia, and elevated levels of glutamine. In addition to ataxia, one patient also showed cerebellar atrophy. The expansion was associated with a relative deficiency of GLS messenger RNA transcribed from the expanded allele, which probably resulted from repeat-mediated chromatin changes upstream of the GLS repeat. Our discovery underscores the importance of careful examination of regions of the genome that are typically excluded from or poorly captured by exome sequencing.


Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/genética , Ataxia/genética , Deficiências do Desenvolvimento/genética , Glutaminase/deficiência , Glutaminase/genética , Glutamina/metabolismo , Repetições de Microssatélites , Mutação , Atrofia/genética , Cerebelo/patologia , Pré-Escolar , Feminino , Genótipo , Glutamina/análise , Humanos , Masculino , Fenótipo , Reação em Cadeia da Polimerase , Sequenciamento Completo do Genoma
12.
BMJ Case Rep ; 12(4)2019 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-31015250

RESUMO

Joubert syndrome (JS) and JS-related disorders are a group of developmental delay, multiple congenital anomalies and complex midbrain-hindbrain malformations. A few cases of JS with multiple pituitary hormone deficiency (MPHD) have been reported in literature. Here, we presented an unusual presentation of JS in a newborn with MPHD. This case is intended to draw attention to the rare association of JS and MDPH by increasing the awareness of this syndrome.


Assuntos
Cerebelo/anormalidades , Anormalidades do Olho/complicações , Terapia de Reposição Hormonal/métodos , Doenças Renais Císticas/complicações , Hormônios Hipofisários/deficiência , Retina/anormalidades , Anormalidades Múltiplas/diagnóstico , Anormalidades Múltiplas/tratamento farmacológico , Anormalidades Múltiplas/etiologia , Anormalidades Múltiplas/genética , Assistência ao Convalescente , Encéfalo/diagnóstico por imagem , Deficiências do Desenvolvimento/diagnóstico , Deficiências do Desenvolvimento/etiologia , Deficiências do Desenvolvimento/genética , Diagnóstico Diferencial , Anormalidades do Olho/diagnóstico , Anormalidades do Olho/tratamento farmacológico , Doenças dos Genitais Masculinos/diagnóstico , Doenças dos Genitais Masculinos/etiologia , Humanos , Hipoglicemia/diagnóstico , Hipoglicemia/etiologia , Recém-Nascido , Doenças Renais Císticas/diagnóstico , Doenças Renais Císticas/tratamento farmacológico , Imagem por Ressonância Magnética , Masculino , Pênis/anormalidades , Hormônios Hipofisários/metabolismo , Esteroides/administração & dosagem , Esteroides/uso terapêutico , Resultado do Tratamento
13.
Genome Med ; 11(1): 12, 2019 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-30819258

RESUMO

BACKGROUND: Neurodevelopmental disorders are genetically and phenotypically heterogeneous encompassing developmental delay (DD), intellectual disability (ID), autism spectrum disorders (ASDs), structural brain abnormalities, and neurological manifestations with variants in a large number of genes (hundreds) associated. To date, a few de novo mutations potentially disrupting TCF20 function in patients with ID, ASD, and hypotonia have been reported. TCF20 encodes a transcriptional co-regulator structurally related to RAI1, the dosage-sensitive gene responsible for Smith-Magenis syndrome (deletion/haploinsufficiency) and Potocki-Lupski syndrome (duplication/triplosensitivity). METHODS: Genome-wide analyses by exome sequencing (ES) and chromosomal microarray analysis (CMA) identified individuals with heterozygous, likely damaging, loss-of-function alleles in TCF20. We implemented further molecular and clinical analyses to determine the inheritance of the pathogenic variant alleles and studied the spectrum of phenotypes. RESULTS: We report 25 unique inactivating single nucleotide variants/indels (1 missense, 1 canonical splice-site variant, 18 frameshift, and 5 nonsense) and 4 deletions of TCF20. The pathogenic variants were detected in 32 patients and 4 affected parents from 31 unrelated families. Among cases with available parental samples, the variants were de novo in 20 instances and inherited from 4 symptomatic parents in 5, including in one set of monozygotic twins. Two pathogenic loss-of-function variants were recurrent in unrelated families. Patients presented with a phenotype characterized by developmental delay, intellectual disability, hypotonia, variable dysmorphic features, movement disorders, and sleep disturbances. CONCLUSIONS: TCF20 pathogenic variants are associated with a novel syndrome manifesting clinical characteristics similar to those observed in Smith-Magenis syndrome. Together with previously described cases, the clinical entity of TCF20-associated neurodevelopmental disorders (TAND) emerges from a genotype-driven perspective.


Assuntos
Anormalidades Craniofaciais/genética , Deficiências do Desenvolvimento/genética , Mutação INDEL , Deficiência Intelectual/genética , Hipotonia Muscular/genética , Síndrome de Smith-Magenis/genética , Fatores de Transcrição/genética , Adolescente , Criança , Pré-Escolar , Anormalidades Craniofaciais/patologia , Deficiências do Desenvolvimento/patologia , Feminino , Humanos , Lactente , Deficiência Intelectual/patologia , Masculino , Hipotonia Muscular/patologia , Síndrome de Smith-Magenis/patologia , Fatores de Transcrição/metabolismo , Adulto Jovem
14.
Mol Genet Genomic Med ; 7(5): e629, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30829465

RESUMO

BACKGROUND: We present a patient with Rett syndrome (RTT; MECP2) and autosomal-recessive succinic semialdehyde dehydrogenase deficiency (SSADHD; ALDH5A1 (aldehyde dehydrogenase 5a1 = SSADH), in whom the current phenotype exhibits features of SSADHD (hypotonia, global developmental delay) and RTT (hand stereotypies, gait anomalies). METHODS: γ-Hydroxybutyric acid (GHB) was quantified by UPLC-tandem mass spectrometry, while mutation analysis followed standard methodology of whole-exome sequencing. RESULTS: The biochemical hallmark of SSADHD, GHB was increased in the proband's dried bloodspot (DBS; 673 µM; previous SSADHD DBSs (n = 7), range 124-4851 µM); control range (n = 2,831), 0-78 µM. The proband was compound heterozygous for pathogenic ALDH5A1 mutations (p.(Asn418IlefsTer39); maternal; p.(Gly409Asp); paternal) and a de novo RTT nonsense mutation in MECP2 (p.Arg255*). CONCLUSION: The major inhibitory neurotransmitter, γ-aminobutyric acid (GABA), is increased in SSADHD but normal in RTT, although there are likely regional changes in GABA receptor distribution. GABAergic anomalies occur in both disorders, each featuring an autism spectrum phenotype. What effect the SSADHD biochemical anomalies (elevated GABA, GHB) might play in the neurodevelopmental/epileptic phenotype of our patient is currently unknown.


Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/genética , Deficiências do Desenvolvimento/genética , Proteína 2 de Ligação a Metil-CpG/genética , Fenótipo , Síndrome de Rett/genética , Succinato-Semialdeído Desidrogenase/deficiência , Erros Inatos do Metabolismo dos Aminoácidos/patologia , Pré-Escolar , Deficiências do Desenvolvimento/patologia , Feminino , Humanos , Síndrome de Rett/patologia , Succinato-Semialdeído Desidrogenase/genética
15.
Genome Biol ; 20(1): 60, 2019 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-30898144

RESUMO

Deletions that fuse two adjacent topologically associating domains (TADs) can cause severe developmental disorders. We provide a formal method to quantify deletions based on their potential disruption of the three-dimensional genome structure, denoted as the TAD fusion score. Furthermore, we show that deletions that cause TAD fusion are rare and under negative selection in the general population. Finally, we show that our method correctly gives higher scores to deletions reported to cause various disorders, including developmental disorders and cancer, in comparison to the deletions reported in the 1000 Genomes Project. The TAD fusion score tool is publicly available at https://github.com/HormozdiariLab/TAD-fusion-score .


Assuntos
Cromatina , Biologia Computacional/métodos , Deficiências do Desenvolvimento/genética , Regulação da Expressão Gênica , Neoplasias/genética , Proteínas de Fusão Oncogênica , Deleção de Sequência , Algoritmos , Genoma Humano , Humanos , Software
16.
Int J Mol Sci ; 20(5)2019 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-30836598

RESUMO

Chromosome 16 is one of the most gene-rich chromosomes of our genome, and 10% of its sequence consists of segmental duplications, which give instability and predisposition to rearrangement by the recurrent mechanism of non-allelic homologous recombination. Microarray technologies have allowed for the analysis of copy number variations (CNVs) that can contribute to the risk of developing complex diseases. By array comparative genomic hybridization (CGH) screening of 1476 patients, we detected 27 cases with CNVs on chromosome 16. We identified four smallest regions of overlapping (SROs): one at 16p13.11 was found in seven patients; one at 16p12.2 was found in four patients; two close SROs at 16p11.2 were found in twelve patients; finally, six patients were found with atypical rearrangements. Although phenotypic variability was observed, we identified a male bias for Childhood Apraxia of Speech associated to 16p11.2 microdeletions. We also reported an elevated frequency of second-site genomic alterations, supporting the model of the second hit to explain the clinical variability associated with CNV syndromes. Our goal was to contribute to the building of a chromosome 16 disease-map based on disease susceptibility regions. The role of the CNVs of chromosome 16 was increasingly made clear in the determination of developmental delay. We also found that in some cases a second-site CNV could explain the phenotypic heterogeneity by a simple additive effect or a pejorative synergistic effect.


Assuntos
Anormalidades Múltiplas/genética , Cromossomos Humanos Par 16/genética , Hibridização Genômica Comparativa , Deficiências do Desenvolvimento/genética , Anormalidades Múltiplas/classificação , Anormalidades Múltiplas/fisiopatologia , Adolescente , Adulto , Criança , Pré-Escolar , Aberrações Cromossômicas , Deleção Cromossômica , Variações do Número de Cópias de DNA/genética , Deficiências do Desenvolvimento/classificação , Deficiências do Desenvolvimento/fisiopatologia , Feminino , Recombinação Homóloga/genética , Humanos , Lactente , Recém-Nascido , Cariótipo , Masculino , Fenótipo , Duplicações Segmentares Genômicas/genética , Adulto Jovem
17.
BMC Med Genet ; 20(1): 38, 2019 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-30841869

RESUMO

BACKGROUND: The KMT2A gene encoded lysine methyltransferase plays an essential role in regulating gene expression during early development and hematopoiesis. To date, 92 different mutations of KMT2A have been curated in the human gene mutation database (HGMD), resulting in Wiedemann-Steiner syndrome (WDSTS) and intellectual disability (ID)/developmental delay (DD). CASE PRESENTATION: In this report, we present a de novo heterozygous deletion mutation [c.74delG; p. (Gly26Alafs*2)] in the KMT2A gene, which was identified by trio-based whole exome sequencing from a 5.5-year-old boy with ID/DD, stereotypic hand movements and blood eosinophilia. Many deleterious germline mutations of KMT2A have been documented to affect development of central nervous system, oral and craniofacial tissues, but not blood eosinophils. CONCLUSIONS: This is the first report of a rare case with ID/DD as well as eosinophilia, resulting from a previously undescribed null mutation of KMT2A. Our findings expand the phenotypical spectrum in affected individuals with KMT2A mutations, and may shed some insight into the role of KMT2A in eosinophil metabolism.


Assuntos
Deficiências do Desenvolvimento/genética , Eosinofilia/genética , Histona-Lisina N-Metiltransferase/genética , Deficiência Intelectual/genética , Proteína de Leucina Linfoide-Mieloide/genética , Deleção de Sequência , Criança , Heterozigoto , Humanos , Mutação com Perda de Função , Masculino , Linhagem , Sequenciamento Completo do Exoma
18.
Medicine (Baltimore) ; 98(8): e14524, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30813157

RESUMO

RATIONALE: Trio family-based whole exome sequencing (WES) is a powerful tool in the diagnosis of rare neurodevelopmental diseases, even in patients with the unclear diagnosis. There have been previous reports of variants in the phosphatidylinositol glycan anchor biosynthesis class T (PIGT) gene associated with multiple congenital anomalies, with a total of 14 affected individuals across 8 families. PATIENT CONCERNS: An 18-month-old boy of Greek ancestry presented with global developmental delay, generalized tonic-clonic seizures, hypotonia, renal cysts, esotropia, bilateral undescended testes, bilateral vesicoureteric reflux, marked cardiac dextroposition, bilateral talipes equinovarus, and dysmorphic features. DIAGNOSIS: WES revealed 2 compound heterozygous variants in the PIGT gene, c.[494-2A>G]; [547A>C]/p.[Asp122Glyfs*35]; [Thr183Pro]. The splicing mutation was demonstrated to lead to the skipping of exon 4. INTERVENTIONS: Seizures, infections, and other main symptoms were treated. OUTCOMES: The patient died at 2 years of age before the molecular diagnosis was achieved. Genetic counseling has been offered to the family. LESSONS: Most of the clinical features of the patient are in agreement with the previously described PIGT cases corroborating the usefulness of WES as a diagnostic tool.


Assuntos
Anormalidades Múltiplas/genética , Aciltransferases/genética , Técnicas de Cultura de Células , Deficiências do Desenvolvimento/genética , Diagnóstico Diferencial , Evolução Fatal , Humanos , Lactente , Masculino , Hipotonia Muscular/genética , Mutação , Reação em Cadeia da Polimerase em Tempo Real , Convulsões/genética , Síndrome , Sequenciamento Completo do Exoma/métodos
19.
J Appl Genet ; 60(2): 151-162, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30706430

RESUMO

Autosomal recessive primary microcephaly (MCPH) is a group of rare neurodevelopmental diseases with severe microcephaly at birth. One type of the disorder, MCPH2, is caused by biallelic mutations in the WDR62 gene, which encodes the WD repeat-containing protein 62. Patients with WDR62 mutation may have a wide range of malformations of cortical development in addition to congenital microcephaly. We describe two patients, a boy and a girl, with severe congenital microcephaly, global developmental delay, epilepsy, and failure to thrive. MRI showed hemispherical asymmetry, diffuse pachygyria, thick gray matter, indistinct gray-white matter junction, and corpus callosum and white matter hypoplasia. Whole exome sequencing revealed the same novel homozygous missense mutation, c.668T>C, p.Phe223Ser in exon 6 of the WDR62 gene. The healthy parents were heterozygous for this mutation. The mutation affects a highly conserved region in one of the WD repeats of the WDR62 protein. Haplotype analysis showed genetic relatedness between the families of the patients. Our findings expand the spectrum of mutations randomly distributed in the WDR62 gene. A review is also provided of the brain malformations described in WDR62 mutations in association with congenital microcephaly.


Assuntos
Deficiências do Desenvolvimento/genética , Microcefalia/genética , Proteínas do Tecido Nervoso/genética , Deficiências do Desenvolvimento/diagnóstico por imagem , Deficiências do Desenvolvimento/fisiopatologia , Feminino , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia , Haplótipos , Homozigoto , Humanos , Masculino , Microcefalia/diagnóstico por imagem , Microcefalia/fisiopatologia , Mutação de Sentido Incorreto/genética , Linhagem , Substância Branca/diagnóstico por imagem , Substância Branca/patologia
20.
Brain Dev ; 41(6): 538-541, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30795918

RESUMO

PPM1D truncating mutations in the last and penultimate exons of the gene have been associated with intellectual disability (ID) syndrome. Only 15 affected patients to-date have been reported with mild-to-severe ID, autistic behavior, anxiety and dysmorphic features. Here, we describe the clinical characteristics and underlying genetics of two unrelated girls with moderate developmental delay and dysmorphic features associated with novel mutations in PPM1D exon 5. The dysmorphic features demonstrated by these two patients are consistent with previously reported patients, including broad forehead, thin upper lip, brachydactyly, and hypoplastic nails. We identified a de novo PPM1D mutation in exon 5 of each patient (c.1250_1251insACCA p.V419Tfs*16 and c.1256_1257insCAAG p.S421Qfs*14) by panel sequencing for 4,813 disease-related genes. Both patients also had frameshift mutations (at different positions) that resulted in the same estimated termination codon at 434. These additional reports add to the growing literature on PPM1D-associated ID syndrome and help delineate the clinical phenotype and genetic basis.


Assuntos
Deficiência Intelectual/genética , Proteína Fosfatase 2C/genética , Proteína Fosfatase 2C/fisiologia , Criança , Pré-Escolar , Deficiências do Desenvolvimento/genética , Éxons/genética , Feminino , Mutação da Fase de Leitura/genética , Genótipo , Humanos , Deficiência Intelectual/metabolismo , Mutação/genética , Fenótipo , Sequenciamento Completo do Exoma/métodos
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