There was no increased methylmalonate, the diagnostic species of methylmalonic acidemia
, in urine organic acids measured by GC-MS.
Unfortunately, the diagnosis of methylmalonic acidemia
in her second child was not allowed as evidence in Stallings murder trial because the judge ruled that her defense attorney had been unable to come up with an expert witness who could testify that the genetic disease could be confused with finding ethylene glycol in the blood.
(MMA) and propionic acidemia (PA) are inborn errors of amino acid metabolism affecting 1 in 50 000 to 1 in 100 000 individuals (6,7).
Nine-year-old Vincent Sanchez and mom Lori of Denver, CO are all smiles this week during his recovery from a combined kidney-liver transplant to treat methylmalonic acidemia
, MMA, a rare and deadly metabolic disorder.
The hyperammonemia observed in methylmalonic acidemia
is thought to arise because accumulated propionyl CoA interferes with formation of N-acetylglutamate, an obligatory activator of carbamyl phosphate synthase, the initial step in urea synthesis (4).
He was initially diagnosed with methylmalonic acidemia
, and a day later the diagnosis was revised to PA when the lab results were completed.
The identification of E-2-methylgutaconic acid, a new isoleucine metabolite, in the urine of patients with [beta]-ketothiolase deficiency, propionic acidemia and methylmalonic acidemia
2-Ethylhydracrylic aciduria has also been reported in several defects at distal steps in the S-pathway, including [beta]-ketothiolase deficiency (15), 2-methyl-3-hydroxybutyryl-CoA dehydrogenase deficiency (29), propionic acidemia (30), and methylmalonic acidemia
attributable to deficiency of mutase or its cofactor vitamin [B.
is now included in all tandem mass spectrometry (MS/MS)-based newborn screening programs (3-5).
In the first weeks after birth, plasma concentrations of tHcy and folate are relatively stable (17), whereas MMA increases dramatically (14), sometimes leading to a benign or transient methylmalonic acidemia
An increase in C3 concentration may indicate the presence of either a propionic acidemia (PA), a methylmalonic acidemia
(MMA), any of various cobalamin defects, or deficiency of vitamin Blz.
In most cases of methylmalonic acidemia
, including those analyzed as part of the present study (see below), the methylmalonate concentrations in urine greatly exceed that of succinate, so that succinate interference will not generally lead to a false-positive result.
5) reported that propionylcarnitine (PrCRN) and carnitine (CRN) esters of 2-methyl-branched fatty acids with chain lengths of four to nine carbons were found in the urine of patients with propionic and methylmalonic acidemia
with a severe chemical but benign clinical phenotype.
PROPIONIC ACIDEMIA (PA), METHYLMALONIC ACIDEMIA
(MMA), AND MULTIPLE CARBOXYLASE DEFICIENCY (MCD)