Abstract
Friedreich ataxia is the most common inherited ataxia, affecting approximately 1/50,000 individuals in the Caucasian population, but yet to be reported in black African. We report here the first genetically confirmed case in a West African family.
A 17-year-old boy of seven siblings from a consanguineous marriage presented with hand tremor and slurred speech at age 11. Parents noticed progressive walking difficulty, skeletal deformities and muscle wasting but no cognitive impairment. Later, he presented with frequent falls, and was wheelchair-bound at age 16. Neurological examination found muscle weakness and atrophy worse in lower limbs, loss of vibration and joint sense, bilateral plantar extensor, brisk reflexes throughout, bilateral pes cavus and scoliosis. No cardiologic abnormalities were found, and blood glucose was normal. The presentation was consistent with Friedreich ataxia, and testing of the frataxin (FXN) gene showed an abnormal GAA trinucleotide expansion in both alleles (999 and 766), confirming the diagnosis of FRDA.
This is the first genetically confirmed Friedreich ataxia in West Africa, expanding the genetic epidemiology of this disease. Studying genetic diseases in populations with diverse backgrounds may give new insights into their pathophysiology for future therapeutic targets.
Keywords: Friedreich ataxia, FXN gene, genetic epidemiology, Mali, West-Africa.