All issues > Volume 48(5); 2005

Case Report

Korean J Pediatr. 2005;48(5):561-564. Published online May 15, 2005.

Isolated 3-Methylcrotonyl CoA Carboxylase Deficiency Detected by Newborn Screening Program Using Tandem Mass Spectrometry

Ju Young JY Kwak¹, Jun Young JY Park¹, Kyung A KA Nam¹, Sang Hi SH Son¹, Son Sang SS Seo¹

¹Department of Pediatrics, Il Sin Christian Hospital, Pusan, Korea

Correspondence Son Sang SS Seo ,Email: sss@ilsin.or.kr

Abstract

Isolated deficiency of 3-methylcrotonyl CoA carboxylase is a rare disorder of the catabolic pathway for leucine and many patients have mild symptoms or no symptom. However, the introduction of tandem mass spectrometry in newborn screening has revealed an unexpectedly high incidence of this disorder. We report an asymptomatic premature infant with isolated 3-methylcrotonyl CoA carboxylase deficiency detected by newborn screening program using tandem mass spectrometry. She was born at preterm, 36 weeks of gestation and her birth weight was 1,912 gm. She was delivered by Cesarian section due to maternal preeclampsia and oligohydramnios. An elevation of 3-hydroxyisovalerylcarnitine in a blood sample obtained at Seven days was detected by tandem mass screening. Massively elevated excretion of 3-hydroxyisovalerate and 3-methylcrotonylglycine was detected in the urine collected at 15 days. L-carnitine(100 mg/kg/day) was administrated orally to correct sencondary carnitine deficiency. Carnitine is conjugated with metabolites, to decrease the potential toxic effects. She is asymptomatic to date, and her growth and development are within normal limits.

Keywords :3-Methylcrotonyl CoA carboxylase , Tandem mass spectrometry