Detection rates and phenotypic spectrum of m.3243A>G in the MT-TL1 gene: A molecular diagnostic laboratory perspective

Abstract

The nucleotide change A to G at position m.3243 in the mitochondrial tRNA leucine (UUR) gene (MT-TL1) is the most common point mutation reported in association with the Mitochondrial Encephalomyopathy, Lactic Acidosis and Stroke-like episodes (MELAS) syndrome. Since the original description of this disorder, factors including random mitochondrial segregation and consequent variable tissue heteroplasmy are recognised to contribute to a much broader phenotypic spectrum associated with the MT-TL1 m.3243A. >. G mutation, often rendering the process of making a diagnosis complex. Reliance on clinicians' referral patterns means that for most molecular diagnostic laboratories, their positive identi..