Prenatal diagnosis of familial hypercholesterolemia: importance of DNA analysis in the high-risk South African population.

In this report on the outcome of the first prenatal diagnosis performed for familial hypercholesterolemia (FH) in a South African family, we aim to demonstrate the value of a population-directed screening strategy to identify FH patients in populations with an enrichment for certain low-density lipoprotein receptor (LDLR) gene mutations. Prenatal diagnosis was offered to an Afrikaner couple, both partners heterozygous for the FH mutation D206E, whose first child was diagnosed with heterozygous FH and the second with homozygous FH. Genomic DNA isolated from parental peripheral blood and subsequently amniotic fluid was amplified by the polymerase chain reaction (PCR) and subjected to mutation analysis. Heterozygosity for mutation D206E was confirmed in both parents, whilst this mutation was not detected in DNA directly amplified from amniotic fluid. To exclude the possibility of a false-negative result due to the limited number of cells in the uncultured amniotic fluid sample, cells were also cultured in vitro, and the DNA extracted and subjected to a second round of analysis. This confirmed the absence of mutation D206E in the fetus. This case illustrates the application of a DNA-based mutation detection technique as a simple and rapid diagnostic aid that can be carried out at a relatively early gestational stage. Prenatal diagnosis of FH, aimed at the detection of homozygous cases, is particularly feasible in populations and families with molecularly defined LDLR gene mutations.