Mutations in TITF1 are not relevant to sporadic and familial chorea of unknown cause

Benign hereditary chorea (BHC; OMIM 118700) is an autosomal dominant movement disorder. Mutations in the thyroid transcription factor 1 (TITF1) gene have been linked with BHC. The phenotype for BHC is highly variable and may include atypical features such as dystonia, slow saccades, and even cognitive deficits. Although BHC is commonly transmitted in a dominant manner, assessment of TITF1 mutations in familial or sporadic patients with late-onset nonprogressive or early-onset progressive chorea is of practical relevance in order to evaluate diagnostic strategies in single patients. In this study, 18 patients with chorea of unknown cause including index patients of three families with autosomal dominantly inherited nonprogressive chorea have been screened for TITF1 mutations by means of denaturating high-pressure liquid chromatography (dHPLC). No sequence variations were detected for the complete open reading frame, suggesting that TITF1 mutations are not a common cause of sporadic or familial chorea of unknown cause. Additionally, linkage analysis excluded TITF1 mutations in a large family with benign hereditary chorea.