Hypertrophic Cardiomyopathy Accompanied by Spinocerebellar Atrophy With a Novel Mutation in Troponin I Gene.

We report the case of a 66 year-old woman with chronic atrial fibrillation, hypertrophic cardiomyopathy (HCM), and spinocerebellar atrophy (SCA). Her mother and first-born son had died of heart disease at the ages of 65 and 16 years, respectively. Four of her 8 siblings had died suddenly of unknown cause or of heart disease, and 2 others of cerebral infarction by the 7th decade. Genetic testing revealed that she had a novel mutation (c. 482C > A, p. Ala161Asp) in the troponin I gene (TNNI3), and no abnormality of the GAA repeat in the frataxin gene. Her older brother with SCA but without HCM was also analyzed, with no abnormality noted in either gene. The Ala161Asp mutation in TNNI3 was implicated in the pathogenesis of her HCM, though an association between HCM and SCA was not revealed.