Silao, Catherine Lynn T. Hernandez, Karen N. Canson, Daffodil M. Estrada, Sylvia C. Chiong, Mary Anne D. Cutiongco-de la Paz, Eva David-Padilla, Carmencita text monographic eng

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INTRODUCTION: Methylmalonic acidemia (MMA) is an autosomal recessive inborn error of metabolism resulting from defects in the nuclear encoded mitochondrial enzyme methylmalonyl-CoA mutase. This study characterizes for the first time the genotype of Filipino patients with MMA. METHODS: Clinical data were collected from 3 patients diagnosed with MMA at the Department of Pediatrics of the Philippine General Hospital from January 2002 to June 2008. The diagnosis was confirmed by urine organic acid analysis using gas chromatography - mass spectrometry (GC-MS). Molecular analysis of the MUT gene was subsequently performed using DNA from dried blood spots or peripheral blood of patients, PCR amplification and direct sequence analysis. RESULTS: The patients presented classically with progressive encephalopathy, metabolic acidosis and secondary hyperammonemia in the early neonatal period. Urine amino and organic acid screens showed increased glycine, methylmalonic acid and other secondary metabolites for methylmalonic aciduria. Mutations detected in the MUT gene analysis [c.1595G>A (p.R532H), c.2011G>A (p.V671I), c.322C>T (p.R108C), c.982C>T (p.L328F) and c.1280G>A (p.G427D)] were compound heterozygous in all patients. CONCLUSION: Our results show the genetic heterogeneity in Filipino MMA patients and helped emphasize the importance of molecular diagnosis particularly in the genetic counseling of the patients and their families. Catherine Lynn T. Sila [and six others] In: Acta Medica Philippina, 2009 vol 43 (1) pages: 29-32 Methylmalonic Acid Metabolism, Inborn Errors 210220 20210220125841.0 D0001J000093