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.