Affiliations: Metabolic Disorders Laboratory, Department of
Biochemistry, Amrita Institute of Medical Sciences and Research Centre, Kerala,
India
Note: [] Corresponding author: Mundakkassery Pullurmanna Narayanan,
Senior Research Fellow, Metabolic Disorders Laboratory, Department of
Biochemistry, Amrita Institute of Medical Sciences and Research Centre,
AIMS-Ponekkara (PO) Kochi-682041, Kerala, India. Tel.: +91 9497274495; Fax: +91
0484 2802020; E-mail: [email protected]
Abstract: The term "organic acidemia" or "organic aciduria" (OA) applies to
inborn errors of metabolism (IEM) in which organic acids accumulate in tissues
and biological fluids. Classical organic acidurias include methylmalonic
aciduria (MMA), propionic aciduria (PA), isovaleric aciduria (IVA) and maple
syrup urine disease (MSUD). Aminoacidurias like phenylketonuria are common in
the western population. Organic acidemias like MMA, PA and MSUD are more common
in Asian countries, especially in India compared with the west. This study was
conducted to determine the prevalence and treatment outcome of organic
acidemias in a study population in India. Four hundred and twenty suspected
cases of organic acidemias with an upper age limit of twelve years were
enrolled over a two years period beteween January, 2007 and December, 2008,
with a three years patient follow-up. Screening tests and thin layer
chromatography followed by quantification of organic acids in urine and
quantification of amino acids in blood by high performance liquid
chromatography were done for detection of organic acidemias. Out of 420
patients, 45 patients (10.7%) were found to have organic acidemias, 15 cases of
MMA, 16 cases of PA, 13 cases of MSUD, and one case of IVA were identified.
Fifteen patients (33.3%) died during the course and remaining 30 are under
therapeutic regimen and showed marked clinical improvement. Therapeutic
regimens based on protein restriction, sodium bicarbonate (to correct
acidosis), L-carnitine and vitamins were given to the patients. Prompt
diagnosis helped to provide specific treatment to majority of these patients
with rapid improvement in symptomatology.
Keywords: Organic acidemias, maple syrup urine disease, methylmalonic aiciduria, propionic aciduria, isovaleric aciduria, tandem mass spectrometry
