[Clinical features and genetic analysis of two Chinese patients with Coffin Siris syndrome-1].

Objective: To explore the genetic basis for two unrelated patients with global developmental delay and coarse facial features.
Methods: Clinical data and family history of the two pedigrees were collected. Whole exome sequencing and Sanger sequencing were carried out to detect potential variants.
Results: The two patients have presented with global developmental delay, coarse facies, muscular hypotonia, congenital heart disease, and pectus excavatum, and were found to harbor two de novo loss-of-function variants of the ARID1B gene, namely c.3586delC (p.Gln1196Serfs*15) and c.4954_4957delACGT (p.Thr1652Glyfs*31). Both variants were unreported previously.
Conclusion: The nonsense variants of the ARID1B gene probably underlay the etiology in these patients. Above finding has enriched the genotypic and phenotypic spectrum of the disease and provided a basis for prenatal diagnosis.