Introduction
Friedreich ataxia is an autosomal recessive cerebellar ataxia due to a
progressive degeneration of corticospinal and spinocerebellar tracts and
posterior columns of spinal cord. It is the most common inherited ataxia
in the world with a prevalence of 1/50,000 people. However, most cases
were described in populations with Caucasian ancestry (Emily et al.,
2019).
Clinically, the disease is characterized by progressive gait and limb
ataxia, dysarthria, loss of vibration and proprioceptive sense, and
pyramidal involvement with upgoing toes (Alper et al., 2003).
Cardiomyopathy, diabetes, scoliosis and pes cavus are common
associated systemic symptoms. MRI shows spinal cord atrophy. The disease
is caused by a triplet (GAA) expansion within the first intron of the
frataxin (FXN) gene located on chromosome 9q13 (Campuzano et al.,
1996). Normal alleles have only a small number of GAA trinucleotide
repeats (usually 8-33), whereas abnormal expanded alleles contain more
than 90 repeats. Despite the high consanguinity rate in some West
African ethnic groups, no genetically confirmed case has been reported
in that region. Here we report the first genetically confirmed West
African family with Friedreich ataxia caused by mutations in theFXN gene.