The Turkish Journal of Pediatrics
2013 , Vol 55 , Num 6
Cobalamin C defect: a patient of late-onset type with homozygous p.R132* mutation
Division of 1Pediatric Metabolism and Nutrition and 2Pediatric Neurology, Department of Pediatrics, Hacettepe University
Faculty of Medicine, Ankara, Turkey, and 3University Children’s Hospital, Basel, Switzerland.
E-mail: kilickorkmaz@yahoo.com.tr
Methylmalonic aciduria and homocystinuria, cobalamin C (cblC) type, is the
most frequent inborn error of vitamin B12 metabolism. The clinical phenotype
includes systemic symptoms and neurological decompensation. Affected
patients can be divided into two broad groups, as early-onset and late-onset.
We present a Turkish patient who had neurological impairment at the age of
four years as presented with late-onset cblC defect. Homozygous c.394C>T;
p.R132* mutation in the MMACHC gene was detected. The patient was
treated with hydroxocobalamin, betaine and folic acid combination with good
clinical and biochemical response.
Keywords :
cobalamin C (cblC) type, late-onset form, hyperhomocysteinemia,
methylmalonic aciduria and homocystinuria, vitamin B12, MMACHC gene.