All issues > Volume 51(9); 2008

Original Article

Korean J Pediatr. 2008;51(9):964-970. Published online September 15, 2008.

Genotype and clinical features of Korean patients with methylmalonic aciduria and propionic aciduria

Eun Hye EH Lee¹, Jung Min JM Ko¹, Jae-Min JM Kim², Han-Wook HW Yoo²

¹Department of Pediatrics, Asan Medical Center University of Ulsan College of Medicine, Seoul, Korea
²Genome Research Center for Birth Defects and Genetic Disorders

Correspondence Han-Wook HW Yoo ,Email: hwyoo@amc.seoul.kr

Abstract

Purpose
: Methylmalonic aciduria (MMA) and propionic aciduria (PA) are inborn errors in the catabolism of branched-chain amino acids. The study was undertaken to investigate the genotypes and clinical features of Korean patients with MMA and PA.
Methods
: This study examined 12 patients with MMA and eight with PA. We analyzed various clinical features, laboratory findings, treatments, and neuro-developmental outcomes. Diagnoses were based on the presence of characteristic compounds detected by amino acid analysis in serum and organic acid analysis in urine. Mutation analysis was performed in the genes of MUT, MMAA, MMAB, and MMACHC for MMA and PCCA and PCCB for PA.
Results
: Among the 20 patients, six patients were diagnosed before one month of age and nine patients were diagnosed after the newborn period. Five patients were diagnosed via a neonatal screening test. Patients with early-onset forms had more severe illness at presentation and generally poor outcomes. A favorable outcome was obtained in 55% patients; most of them were of a late-onset type or diagnosed by neonatal mass screening test without symptoms. Genotypes were confirmed in all patients with MMA. We detected 11 different mutations by MUT gene analysis in 10 patients, and three different mutations in MMACHC genes in two patients. PCCA and PCCB gene mutations were identified in 14 of the 16 alleles, in eight patients with PA.
Conclusion
: Organic aciduria is a fatal disease; however, better outcomes are expected whenever early diagnosis and prompt management are made possible. Mutation analysis is useful for confirming diagnoses and planning management strategies.

Keywords :Methylmalonic aciduria, Propionic aciduria, MUT, MMACHC, PCCA, PCCB