{Reference Type}: Case Reports
{Title}: Mosaicism of a Truncating Variant of CASK Causes Congenital Heart Disease and Neurodevelopmental Disorder.
{Author}: Abe-Hatano C;Yokoi T;Ida K;Kurosawa K;
{Journal}: Mol Syndromol
{Volume}: 13
{Issue}: 6
{Year}: Jan 2023
{Factor}: 1.494
{DOI}: 10.1159/000524375
{Abstract}: <B>UNASSIGNED: </B>Calcium/calmodulin-dependent serine protein kinase (CASK) gene mutations cause microcephaly with pontine and cerebellar hypoplasia (MICPCH) and X-linked intellectual disability. Congenital heart disease (CHD) is a rare complication reported in only 4 male patients with full loss-of-function mutations. Here, we report the first male patient with mosaicism of a truncating variant of CASK complicated by CHD.<BR><B>UNASSIGNED: </B>The patient is a 6-year-old male with MICPCH, ventricular septal defect, and developmental delay. He achieved rolling over but can not speak meaningful words. We identified a somatic mosaic variant of CASK: c.[725=/G>A], p.(W242*) and high mosaic ratios of 90% and 84% for mutant alleles in peripheral blood lymphocytes and skin fibroblasts, respectively. His developmental delay was severe but milder than that of previously reported CHD patients.<BR><B>UNASSIGNED: </B>Truncating CASK variants may be associated with CHD, even in a mosaic state, and even a low normal allele ratio could lengthen survivorship.