POLYMORPHIC TRINUCLEOTIDE REPEAT IN THE MEF2A GENE AT 15Q26 IS NOT EXPANDED IN FAMILIAL CARDIOMYOPATHIES

A trinucleotide repeat polymorphism in the MEF2A gene is described. ME F2A is expressed early in cardiac muscle development; thus the possibi lity of linkage between this polymorphism and familial cardiomyopathie s was investigated in three families not linked to genes coding for kn own sarcomeric proteins. MEF2A was excluded as a candidate for dilated cardiomyopathy (DCM) (LOD of -9.03) and hypertrophic cardiomyopathy ( HCM) (LODs of -5.43 and -2.44) in these families. Because expansion of triplet repeats has been shown to be responsible for several inherite d diseases, 121 unrelated HCM probands and 28 unrelated DCM probands w ere examined for evidence of expansion of this repeat. No expansion of this trinucleotide repeat was seen in any of the 149 cardiomyopathy p robands. (C) 1997 Academic Press Limited.