A novel HECW2 variant in an infant with congenital long QT syndrome.

Pathogenic variants of HECW2 have been reported in cases of neurodevelopmental disorder with hypotonia, seizures, and absent language (NDHSAL; OMIM #617268). A novel HECW2 variant (NM_001348768.2:c.4343 T > C,p.Leu1448Ser) was identified in an NDHSAL infant with severe cardiac comorbidities. The patient presented with fetal tachyarrhythmia and hydrops and was postnatally diagnosed with long QT syndrome. This study provides evidence that HECW2 pathogenic variants can cause long QT syndrome along with neurodevelopmental disorders.