RESUMO
Despite the improved accuracy of next-generation sequencing (NGS), it is widely accepted that variants need to be validated using Sanger sequencing before reporting. Validation of all NGS variants considerably increases the turnaround time and costs of clinical diagnosis. We comprehensively assessed this need in 1109 variants from 825 clinical exomes, the largest sample set to date assessed using Illumina chemistry reported. With a concordance of 100%, we conclude that Sanger sequencing can be very useful as an internal quality control, but not so much as a verification method for high-quality single-nucleotide and small insertion/deletions variants. Laboratories might validate and establish their own thresholds before discontinuing Sanger confirmation studies. We also expand and validate 23 copy number variations detected by exome sequencing in 20 samples, observing a concordance of 95.65% (22/23).
Assuntos
Exoma/genética , Sequenciamento de Nucleotídeos em Larga Escala , Mutação/genética , Variações do Número de Cópias de DNA/genética , Humanos , Reprodutibilidade dos TestesRESUMO
Campomelic dysplasia is a rare disorder characterized by skeletal and extraskeletal defects. Up to two-thirds of affected XY individuals have a gradation of genital defects or may develop as phenotypic females. This syndrome is caused by alterations in SRY-related HMG-Box Gene 9 (SOX9), a transcription factor essential in both chondrocyte differentiation and sex determination. We report a 27-week fetus with ambiguous genitalia and upper and lower extremities bone malformations. Gross photographs, radiologic and pathological studies led the clinical diagnosis to campomelic dysplasia. A new frameshift mutation (p.Pro415Serfs*163) was identified in the SOX9 gene by genetic analysis. This mutation not only alters almost the entire sequence of the C-terminal transactivation (TA) domain of SOX9, but also enlarges it. This altered sequence does not resemble any other existing sequence. Since TA domain is entirely affected, SOX9 could not establish its normal function. The comparison between p.Pro415Serfs*163 and other frameshift mutations that enlarges SOX9 showed the same nucleotides added. This new sequence is not conserved either. We speculate that the fact of adding a sequence downstream of the C-terminal domain alters SOX9 and leads to campomelic dysplasia. The clinical information is essential not only to achieve a correct diagnosis in fetuses with pathologic ultrasound findings, but also to offer a proper genetic counseling.
Assuntos
Displasia Campomélica/genética , Fatores de Transcrição SOX9/genética , Adulto , Sequência de Aminoácidos , Displasia Campomélica/diagnóstico , Feminino , Feto/diagnóstico por imagem , Feto/patologia , Mutação da Fase de Leitura , Humanos , Dados de Sequência Molecular , Gravidez , RadiografiaRESUMO
Pleural effusion secondary to vascular perforation and leakage of total parenteral nutrition (TPN) is a rare complication of central lines. We report such a case and urge physicians to familiarize with recognition and management of this rare complication as both TPN and central catheter lines are widely used techniques.
Assuntos
Cateterismo Venoso Central/efeitos adversos , Cateterismo Periférico/efeitos adversos , Nutrição Parenteral Total , Derrame Pleural/etiologia , Feminino , Humanos , Pessoa de Meia-Idade , Derrame Pleural/prevenção & controleAssuntos
Alcaptonúria/epidemiologia , Alcaptonúria/genética , Dioxigenases , Mutação/genética , Oxigenases/genética , Idoso , Alcaptonúria/enzimologia , Mapeamento Cromossômico , DNA/genética , Análise Mutacional de DNA , República Dominicana/epidemiologia , Efeito Fundador , Triagem de Portadores Genéticos , Homogentisato 1,2-Dioxigenase , Humanos , Masculino , Mucosa Bucal/química , Mucosa Bucal/citologia , Mutagênese/genética , Polimorfismo de Nucleotídeo Único/genéticaAssuntos
Substituição de Aminoácidos/genética , Proteínas do Olho/genética , Genes Dominantes/genética , Proteínas de Filamentos Intermediários/genética , Degeneração Macular/genética , Glicoproteínas de Membrana , Mutação de Sentido Incorreto , Proteínas do Tecido Nervoso/genética , Arginina/genética , Cisteína/genética , Eletroforese em Gel de Poliacrilamida , Histidina/genética , Humanos , Periferinas , Reação em Cadeia da Polimerase , Degeneração Retiniana/genética , Triptofano/genética , Tirosina/genéticaRESUMO
A study of choroideremia gene was performed in Spanish families affected with this disorder. One abnormal pattern was detected in exon eight corresponding to a new mutation not described before. The mutation was identified as a nonsense mutation S340X.