Screening well-baby

Neural and behavioral screening measuresadministered during a routine well-baby physical exam or through parent reports... 

The study population consisted of 1884 healthy newborns, infants, children and adolescents enrolled from nurseries, well-baby clinics, kindergartens, and elementary and secondary schools. All children were screened by a specially designed questionnaire, then examined on supine position by a pediatrician, and checked by a pediatric cardiologist. Age was expressed as days, months and years attained at the last birthday. They were divided into twelve age groups newborns aged less than 1 day, 1-3 days, 3-7 days, and 7-30 days infants aged 1-3 months, 3-6 months, and 6-12 months children of 1-3 years, 3-6 years, 6-9 years, 9-13 years and adolescents, 13-18 years. 

Vitamin B12 deficiency must be excluded, even in the newborn (see Section 11.2.6 below), particularly when the mother is a vegetarian, and maternal serum vitamin B12 concentrations may be helpful. Patients without vitamin Bi2 deficiency have also been reported with methylmalonic aciduria at low levels (12-115 mg day) which is unresponsive to vitamin B12 therapy (Giorgio et aly 1976) and apparently occurs as a result of reduced activity of methylmalonyl-CoA mutase. Such patients with urinary methylmalonic acid concentrations about 10-50 times normal may also be observed during well-baby screening (Shih et al, 1976), but no confusion with the true congenital methylmalonic acidurias where concentrations are 1000 times or more, and metabolites of propionyl-CoA are also excreted, should occur if the proper analytical procedures are employed. 

Reference has been made in earlier sections to the occurrence of severe megaloblastic anaemia associated with methylmalonic aciduria and homo-cystinuria in the breast-fed infant of a strictly vegetarian mother, due to to vitamin B 12-deficiency (Section 11.2.3), and to the mild asymptomatic methylmalonic aciduria that may be observed during well-baby screening programmes (Section 11.2.2). Williams and Ireland (1977) have also reported neonatal acidosis associated with transient methylmalonic aciduria and vitamin Bi2 deficiency. Urinary excretion was about twice normal. In the authors ... 

The metabolic clinic immediately calls out the results to the provider of the infant, now 9 days old. The baby is in a neonatal intensive care unit due to prematurity but is reportedly doing weU. However, the day the results are reported, the infant is no longer feeding well. The metabolic clinic requests that confirmatory testing of plasma acylcamitine profile and urine organic acid screen be obtained. 

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