Gene Frequencies of Methylmalonic Acidemia Disease at the Global Level and Compiling the Pathogenic Mutations in the Iranian Population

Methylmalonic acidemia (MMA) is a rare autosomal recessive metabolic disorder resulting from a genetic defect in methylmalonyl-CoA mutase (MCM) or a defect in the biosynthesis of its cofactor, adenosyl-cobalamin (AdoCbl). The disease is caused by a mutation in six main genes (MUT, MMAA, MMAB, MMADHC, MMACHC, and MCEE). In this investigation, we estimate MMAdisease gene frequencies globally and report MMA-causative mutations in the Iranian population.

Human gene mutation database (HGMD) has been utilized to estimate MMA-disease gene frequencies. To compile MMA mutations in Iran, we systematically reviewed PubMed, Google Scholar, CIVILICA, Magiran, and SID databases to explore relevant articles in English and Persian.

The frequencies of causative genes among MMA patients at the global level were as follows: MUT (64.14%), MMACHC (17.74%), MMAA (13.48%), MMAB (7.1%), MMADHC (2.9%), and MCEE (0.85%). Until February 11, 2024, 24 MMA mutations had been compiled from the Iranian population; of which 11 mutations (45.8%) had been diagnosed only in Iran and had not been addressed in other populations yet.

Collection and recognition of MMA mutations in the Iranian population can be helpful for early diagnosis and treatment before the onset of neurological manifestations in neonates.