Material and Methods
Patient was seen under a research protocol approved by the institutional
ethical committee of Faculté de Médecine et d’Odonto-stomatologie
(FMOS), Mali. The patient was examined by a multidisciplinary team
including neurologist, ophthalmologist, cardiologist and ENT specialist
after giving an informed consent. Brain MRI, nerve conduction study, and
blood chemistries including vitamins B12 and E, blood glucose and blood
cell counts were performed to consolidate our diagnosis and to exclude
other ataxia causes. DNA was extracted from peripheral blood in the
patient for genetic testing. Genetic testing was done by Athena
Diagnostics in Marlborough, Massachusetts, USA.
Direct testing for the repeat expansion mutation in the FXN gene
was performed by PCR amplification of the repeat region followed by
high-resolution electrophoresis to determine the number of tandem
repeats in each allele. Southern blot analysis was used, as necessary,
to confirm homozygosity of normal alleles and to verify the number of
repeats in highly expanded alleles. Southern blot analysis is performed
using Bsi HKA restriction digestion of genomic DNA and
hybridization with a gene specific probe. This methodology is greater
than 99% accurate for the detection of repeat expansion mutations.