In an individual with Baraitser-Winter syndrome-2 (BRWS2; 614583), Riviere et al. (2012) identified a heterozygous C-to-A transversion at nucleotide 608 of the ACTG1 gene, resulting in an thr-to-lys substitution at codon 203 (T203K). This mutation occurred de novo in the patient and was not observed in 203 other exomes sequenced.