GNAQ and 22q11.2 deletion syndrome: Most cases are sporadic but rare cases have been described in neurofibromatosis type 1 (NF1), Down syndrome (trisomy 21) [36], DiGeorge syndrome (22q11.2 deletion syndrome) [37], Sturge-Weber syndrome (somatic GNAQ variants) [38] and familial melanoma-astrocytoma syndrome (CDKN2A/B loss) [39].