Large 3‐Mb deletions at 22q11.2 locus in Parkinson's disease and schizophrenia

22q11.2 microdeletions are among the most common deletions found in humans. Whereas most cases present in early childhood, a large fraction remain undetected into adulthood. Adult carriers are at increased risk of developing schizophrenia.1 More recently, these deletions have also been associated with Parkinson's disease (PD). Butcher and colleagues reported that a small proportion of 22q11.2 deletion carriers aged above 35 years have developed early‐onset PD,2 although the diagnosis was delayed in individuals undergoing antipsychotic treatment for schizophrenia. Subsequently, Mok and colleagues screened for the deletion in 9,387 PD cases and 13,863 controls3 and identified 8 carriers among cases, but none in controls. This deletion was particularly enriched among early‐onset cases. Most of these studies were conducted in samples of European ancestry, but the prevalence in Asian samples is unknown.NRF (Natl Research Foundation, S’pore)ASTAR (Agency for Sci., Tech. and Research, S’pore)NMRC (Natl Medical Research Council, S’pore)Accepted versio