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Treatment of the cbl B form of methylmalonic acidaemia with adenosylcobalamin
Author(s) -
Batshaw M. L.,
Thomas G. H.,
Cohen S. R.,
Matalon R.,
Mahoney M. J.
Publication year - 1984
Publication title -
journal of inherited metabolic disease
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 102
eISSN - 1573-2665
pISSN - 0141-8955
DOI - 10.1007/bf01805805
Subject(s) - adenosylcobalamin , methylmalonic acidemia , medicine , human genetics , methylmalonic acid , chemistry , cobalamin , vitamin b12 , biochemistry , gene
A 30‐month‐old girl was found to have the cbl B mutant form of methylmalonic aciduria by complementation analysis of fibroblasts. She was unresponsive to hydroxycobalamin and was treated with intramuscular adenosylcobalamin (AdoCbl), the deficient coenzyme, at a dose of 1 mg/24 h during a period of clinical stability. Serum cobalamin increased from 770 to 54 200 pg/ml. Mean urinary methylmalonic acid excretion was 409 mg/24 h prior to therapy. There was a transient fall in methylmalonic acid excretion during the first 5 days of therapy (range 167–245 mg/24 h) followed by a rise in excretion toward pretreatment levels (range 317–485 mg/24 h) during the second week of AdoCbl treatment. There was no change in plasma ammonia, glycine or serum bicarbonate level. We interpret the failure of this child to have a sustained and clinically significant response to AdoCbl as indicating that AdoCbl did not reach or enter the mitochondria intact, or in some other way was unavailable as a coenzyme for the methylmalonyl CoA mutase apoenzyme.