INTRODUCTION: One of the main features of Friedreich's ataxia (FA) is phenotypic variability that can now be explained by the molecular mechanism (GAA expansion) underlying the disease. MATERIALS AND METHODS: We have analyzed genotype-phenotype correlations in a group of 40 patients homozygous for the GAA expansion. RESULTS: The smaller GAA expansion (GAA1 allele) size correlated with age at onset and progression disease rate, but we found no correlation between the larger GAA expansion (GAA2 allele) size and these clinical parameters. The frequency of pes cavus, scoliosis, axonal sensory neuropathy and areflexia increased with the size of GAA1, whereas some signs such as sphincter disturbances, cerebellar atrophy on MRI, amyotrophy, dysarthria and decreased vibration sense were associated with increased duration of the disease. CONCLUSION: GAA1 size is the main determinant of FA phenotype and GAA2 size is a poor predictor of clinical variation. Some clinical features are independent of GAA1 and GAA2 sizes and are determined by the duration of the disease.
INTRODUCTION: One of the main features of Friedreich's ataxia (FA) is phenotypic variability that can now be explained by the molecular mechanism (GAA expansion) underlying the disease. MATERIALS AND METHODS: We have analyzed genotype-phenotype correlations in a group of 40 patients homozygous for the GAA expansion. RESULTS: The smaller GAA expansion (GAA1 allele) size correlated with age at onset and progression disease rate, but we found no correlation between the larger GAA expansion (GAA2 allele) size and these clinical parameters. The frequency of pes cavus, scoliosis, axonal sensory neuropathy and areflexia increased with the size of GAA1, whereas some signs such as sphincter disturbances, cerebellar atrophy on MRI, amyotrophy, dysarthria and decreased vibration sense were associated with increased duration of the disease. CONCLUSION:GAA1 size is the main determinant of FA phenotype and GAA2 size is a poor predictor of clinical variation. Some clinical features are independent of GAA1 and GAA2 sizes and are determined by the duration of the disease.
Authors: Bart E Drinkard; Randall E Keyser; Scott M Paul; Ross Arena; Jonathan F Plehn; Jack A Yanovski; Nicholas A Di Prospero Journal: Arch Phys Med Rehabil Date: 2010-07 Impact factor: 3.966
Authors: Alison La Pean; Neal Jeffries; Chelsea Grow; Bernard Ravina; Nicholas A Di Prospero Journal: Mov Disord Date: 2008-10-30 Impact factor: 10.338
Authors: Christian Rummey; John M Flynn; Louise A Corben; Martin B Delatycki; George Wilmot; Sub H Subramony; Khalaf Bushara; Antoine Duquette; Christopher M Gomez; J Chad Hoyle; Richard Roxburgh; Lauren Seeberger; Grace Yoon; Katherine D Mathews; Theresa Zesiewicz; Susan Perlman; David R Lynch Journal: Ann Clin Transl Neurol Date: 2021-05-05 Impact factor: 4.511
Authors: Ashlee Long; Jill S Napierala; Urszula Polak; Lauren Hauser; Arnulf H Koeppen; David R Lynch; Marek Napierala Journal: PLoS One Date: 2017-12-19 Impact factor: 3.240