Incidental finding of alpha-methylacyl-CoA racemase deficiency in a patient with oculocutaneous albinism type 4.

Genome-wide studies may lead to the discovery of genetic variants of potential clinical importance beyond the aims of the study. We performed single nucleotide polymorphism array analysis in a boy with oculocutaneous albinism to identify copy-neutral regions of homozygosity harboring genes involved in melanin biosynthesis. An unanticipated homozygous deletion of chromosome 5p13.3 was discovered, encompassing not only the OCA gene SLC45A2, but also four additional genes. This led to an unexpected presymptomatic diagnosis of alpha-methylacyl-CoA racemase deficiency in the same patient.