Application of oligonucleotide array CGH in the detection of a large intragenic deletion in POLG associated with Alpers Syndrome

Mutations in the polymerase gamma (POLG) gene are among the most common causes of mitochondrial disease and more than 160 POLG mutations have been reported. However, a large proportion of patients suspected of having POLG mutations only have one (heterozygous) definitive pathogenic mutation identified. Using oligonucleotide array CGH, we identified a compound heterozygous large intragenic deletion encompassing exons 15-21 of this gene in a child with Alpers syndrome due to mtDNA depletion. This is the first large POLG deletion reported and the findings show the clinical utility of using array CGH in cases where a single heterozygous mutation has been identified in POLG. (C) 2010 Elsevier B.V. and Mitochondria Research Society. All rights reserved.