Screening for familial hypercholesterolemia in 5000 neonates: a recall study.

To investigate the feasibility of screening for familial hypercholesterolemia, apolipoprotein B (Apo B) levels were determined in dried blood spot samples on neonatal screening cards from 5000 consecutively born neonates, by radial immunodiffusion assay. The 103 infants with Apo B levels in the top 2% were recalled for repeat dried blood spot Apo B determinations. Forty-five of the 103 infants were retested, and serum lipid profiles and Apo B levels were determined for both parents of 43 of these infants, and for the mother only for the other two infants. The recalled "top 2%" group had a higher proportion of females, a higher mean birth weight, a higher mean gestational age and a higher proportion of infants sampled initially on day 5 than in the total screened population, consistent with our previously determined influence of these factors on Apo B levels at screening. The retested group (n = 45) was representative of the total recalled group (n = 103) with respect to Apo B levels at screening, sex, birth weight, gestational age, and age at sampling for screening. The infants' mean +/- SD age at retesting was 12.3 +/- 3.3 months. Their mean Apo B value on retesting was 0.65 +/- 0.20 g/liter of whole blood (range 0.30 to 1.16 g/liter). Two fathers had had coronary bypass surgery by the age of 40 and had type II lipid profiles and elevated serum Apo B levels. For both, their child had elevated Apo B levels at recall (both 1.05 g/liter of whole blood).(ABSTRACT TRUNCATED AT 250 WORDS)