There is little known or published about the prevalence of primary mitochondrial respiratory chain disease in Africa, owing to resource restraints and the necessary prioritisation of health funding for preventable disease.

Aim: To review the pattern of common mitochondrial genetic mutations identified in a genetically diverse South African population from 1992-2012

Method:  PCR analysis and standard methods of restriction enzyme digestion and/or sequencing of mitochondrial and autosomal DNA from blood, fibroblasts, urine and or muscle were performed as part of clinical diagnostic service.

Results:

There were 907 referrals for analysis. 211 (23%) samples were from persons of indigenous African ancestry; the remainder were of European or mixed descent.  Sixty three patients had mutations (7%). The most common was mt.3243A>G, MELAS (n=17). Mt.8993T>C NARP occurred in 9 patients, 8 from the same mixed ancestry family.  Unusual mutations included Leigh Syndrome (LS) with mt.13094T>C, LS with mt.14597T>C, and two unrelated children found to be compound heterozygous for a known splice site mutation (c.751+6T>G) and an undescribed p.56 Ala>Gly in exon3 of the Surf1 gene. 5/10(50%) of patients with common deletions and 5/53 (9%) patients with point mutations had indigenous African ancestry. The incidence of positive test results was 4.7% (10/211) in the African sub population compared with 7.5% (53/706) in the rest of the group.

Conclusion: There is a trend for presentation with common deletions to be more prevalent than common point mutations in this Sub Saharan indigenous African population.  Further research is indicated to validate these observations.