Neonatal Diagnosis of Familial Hypercholesterolemia in Newborns Born to a Parent With a Molecularly Defined Heterozygous Familial Hypercholesterolemia

Abstract

Abstract This study was designed to compare blood lipid levels in newborn individuals with molecularly defined heterozygous familial hypercholesterolemia [FH] to those in nonaffected babies and to clarify the value of lipid determinations in assessment of diagnosis of FH at birth and 1 year of age. Twenty-five babies were born to 21 parents with DNA-documented heterozygous FH. Analysis of their cord blood samples revealed 11 newborns with the FH-North Karelia [FH-NK] mutation, 3 newborns with the FH-Helsinki [FH-HKI] mutation, and 11 nonaffected newborns. Cord serum total [TC] and LDL cholesterol [LDL-C] levels (mean±SD) in affected newborns (2.60±0.70 and 1.77±0.56, respectively) were significantly ( P <.001) higher than those in nonaffected ones (1.54±0.23 and 0.78±0.15, respectively) and another cohort of 30 randomly selected control samples from apparently healthy newborns (1.84±0.46 and 1.03±0.30, respectively). However, there was overlapping of individual lipid levels in these three groups precluding the use of TC or LDL-C determinations in neonatal diagnosis of FH. In contrast, 1 year follow-up samples from 10 affected and 7 nonaffected individuals, as well as additional samples collected from another group of 8 affected and 9 nonaffected individuals, indicated that serum cholesterol levels showed much greater increment in children with FH. Thus, at the age of 1 year the mean serum TC and LDL-C levels in the affected infants (8.38±1.18 and 7.02±1.07, respectively) were much higher ( P <.001) than the corresponding levels (4.40±0.66 and 2.89±0.68, respectively) in the nonaffected infants, and the individual ranges of TC and LDL-C levels were nonoverlapping in these two groups. Serum HDL cholesterol [HDL-C] levels in 1-year-old children with FH (0.95±0.14) were approximately 20% lower than those of their nonaffected counterparts (1.16±0.15, P <.001), after being similar at birth. In conclusion, phenotypic expression of heterozygous FH, as defined by molecular analysis of genomic DNA, is evident in serum LDL-C (but not HDL-C) levels already at birth, but for diagnostic purposes blood lipid determinations carried out at the age of 1 year are highly superior to those performed at birth.