Intellectual Developmental Disorder with Cardiac Arrhythmia

**Semantic type:** Disease or Syndrome

**Definition:** An autosomal recessive condition caused by mutation(s) in the GNB5 gene, encoding guanine nucleotide-binding protein subunit beta-5. It is characterized by severe intellectual disability, poor speech acquisition, and cardiac arrhythmia. Biallelic missense mutation in the GNB5 gene can cause language delay and attention deficit-hyperactivity disorder/cognitive impairment with or without cardiac arrhythmia, which is a less-severe disorder with overlapping features.

**Synonyms:** - IDDCA