[Expand newborn screening using tandem mass spectrometry: two years' experience in Nuevo León, Mexico]. / Tamiz metabólico neonatal por espectrometría de masas en tándem: dos años de experiencia en Nuevo León, México.

ABSTRACT

OBJECTIVE: To initiate a statewide expanded metabolic screening program in neonates with the purpose of identifying the most common inborn errors of metabolism. MATERIAL AND METHODS: From March 2002 through February 2004, a blood sample was obtained between 24 and 48 hours after delivery from every consecutive child born in public hospitals in Nuevo León. It was spotted on filter paper and analyzed by tandem mass spectrometry for expanded metabolic screening. RESULTS: A total of 42 264 samples were analyzed. Were obtained seven positive results, one for each disorder homocystinuria, hyperphenylalaninemia, citrulinemia, transient tyrosinemia, 3-methylcrotonyl CoA carboxylase deficiency, 3-hydroxy-3-methylglutaryl CoA deficiency, and classic galactosemia. CONCLUSIONS: The estimated incidence of inborn errors of metabolism is 15 000, with a false positive rate of 0.22%. The program permitted the identification of metabolic disorders in the newborn, allowing an early intervention and prevention of life-threatening events and permanent neurological damage.