Utility of trio-based exome sequencing in the elucidation of the genetic basis of isolated syndromic intellectual disability: illustrative cases

Autor(es)

Carneiro, Thaise N. R. ^[1] ; Krepischi, Ana C. V. ^[1] ; Costa, Silvia S. ^[1] ; da Silva, Israel Tojal ^[2] ; Vianna-Morgante, Angela M. ^[1] ; Valieris, Renan ^[2] ; Ezquina, Suzana A. M. ^[1] ; Bertola, Debora R. ^[3] ; Otto, Paulo A. ^[1] ; Rosenberg, Carla ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Biosci, Dept Genet & Evolutionary Biol, Human Genome & Stem Cell Res Ctr, Sao Paulo - Brazil

^[2] AC Camargo Canc Ctr, Int Res Ctr, Lab Computat Biol & Bioinformat, Sao Paulo - Brazil

^[3] Univ Sao Paulo, Hosp Clin, Med Sch, Genet Unit, Inst Crianca, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: APPLICATION OF CLINICAL GENETICS; v. 11, p. 93-98, 2018.
• Citações Web of Science: 9

Resumo

Introduction: Exome sequencing is recognized as a powerful tool for identifying the genetic cause of intellectual disability (ID). It is uncertain, however, whether only the exome of the proband should be sequenced or if the sequencing of parental genomes is also required, and the resulting increase in diagnostic yield justifies the increase in costs. Patients and methods: We sequenced the exomes of eight individuals with sporadic syndromic ID and their parents. Results and discussion: Likely pathogenic variants were detected in eight candidate genes, namely homozygous or compound heterozygous variants in three autosomal genes (ADAMTSL2, NALCN, VPS13B), one in an X-linked gene (MID1), and de novo heterozygous variants in four autosomal genes (RYR2, GABBR2, CDK13, DDX3X). Two patients harbored rare variants in two or more candidate genes, while in three other patients no candidate was identified. In five probands (62%), the detected variants explained their clinical findings. The causative recessive variants would have led to diagnosis even without parental exome sequencing, but for the heterozygous dominant ones, the exome trio-based approach was fundamental in the identification of the de novo likely pathogenic variants. (AU)

• Processo FAPESP: 13/08028-1 - CEGH-CEL - Centro de Estudos do Genoma Humano e de Células-Tronco
• Beneficiário: Mayana Zatz
• Linha de fomento: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 12/50981-5 - Uso de arrays genômicos de alta resolução e next generation sequencing no diagnóstico de deficiência mental e anomalias congênitas
• Beneficiário: Francine Campagnari Guilhem
• Linha de fomento: Auxílio à Pesquisa - Pesquisa Inovativa em Pequenas Empresas - PIPE