Recently, an individual carrying a homozygous deletion spanning three genes, BCL2L, GNB5 and MYO5C, was reported to display a phenotype which overlaps significantly with the IDDCA manifestations,81 further confirming that this phenotype is associated with loss of function of GNB5. Here, GNB5 is linked to gnb5-related intellectual disability-cardiac arrhythmia syndrome.