ClinVar

Description

The heterozygous p.Arg37His variant in SMARCB1 was identified by our study in one individual with Coffin-Siris syndrome. The p.Arg37His variant in SMARCB1 has been reported in >10 individuals with Coffin-Siris syndrome (PMIDs: 22726846, 29907796, 33057194, 34906496, 36964972), but was absent from large population studies. The number of reported affected individuals with this variant is greater than expected compared to non-affected individuals with this variant. This variant has been reported in ClinVar (Variation ID: 88893) and has been interpreted as uncertain significance by two submitters, likely pathogenic by two submitters, and pathogenic by three submitters. This variant is assumed de novo in 11 individuals, but maternity and paternity have not been confirmed (PMIDs: 22726846, 29907796, 34906496, 36964972). Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. The number of missense variants reported in SMARCB1 in the general population is lower than expected, suggesting there is little benign variation in this gene and slightly increasing the possibility that a missense variant in this gene may not be tolerated. In summary, although additional studies are required to fully establish its clinical significance, this variant is likely pathogenic for autosomal dominant Coffin-Siris syndrome. ACMG/AMP Criteria applied: PM2_Supporting, PS4_Moderate, PP2, PM6, PP3_Moderate (Richards 2015).