In vitro "responsive" methylmalonic acidemia: A new variant

Celia I. Kaye, Grant Morrow, Henry L. Nadler

Research output: Contribution to journalArticlepeer-review

13 Scopus citations


Two infants with elevated levels of methylmalonic acid in plasma and urine were found to have abnormal metabolism of propionate-1-14C in cultivated skin fibroblasts and deficient activity of methylmalonyl CoA carbonyl mutase in homogenates of liver and fibroblasts. Addition of 5′-deoxyadenosylcobalamin to the assay systems corrected these defects. Despite the in vitro responses, parenteral treatment of the patients with high doses of vitamin B12 failed to decrease plasma or urinary methylmalonic acid. One of the patients exhibited significant hyperammonemia but failed to develop acidosis or ketosis throughout her clinical course. The significance of this new variant of methylmalonic acidemia with respect to the enzymatic basis of this inborn error and with respect to prenatal detection and genetic counseling is discussed.

Original languageEnglish (US)
Pages (from-to)55-59
Number of pages5
JournalThe Journal of pediatrics
Issue number1
StatePublished - Jul 1974
Externally publishedYes

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health


Dive into the research topics of 'In vitro "responsive" methylmalonic acidemia: A new variant'. Together they form a unique fingerprint.

Cite this