For all patients, variants reported as validated polymorphisms with a minor allele frequency >0.01 (1%) in publicly available human variation resources (including dbSNP144, NHLBI GO Exome Sequencing Project, UK10, 1000 Genomes, Exome Variant Server [EVS], and Exome Aggregation Consortium [ExAC] browser) and variants present in in-house control individuals were filtered out. In silico prediction of the mutation pathogenicity was performed using ANNOVAR and the dbNSFP database (v3.0a) (sites.google.com/site/jpopgen/dbNSFP). Putative causative variants were validated by Sanger sequencing and investigated in the probands' parents to determine whether the mutations were inherited or had occurred de novo.
