Also, two patients (RM4073 and RM4285) had a 622 kb duplication on chr 5q12.1 affecting five genes, including the NDUFAF2 gene that encodes a chaperone for mitochondrial complex I assembly and that was found to be implicated in attention-deficit/hyperactivity disorder (Lesch et al. 2011). The gene discussed is NDUFAF2; the disease is attention deficit-hyperactivity disorder.