Variable expression of hypercholesterolemia in apolipoprotein E2*Arg136 ->Cys heterozygotes

In the process of population screening for apo E gene polymorphism with the PCR and subsequent restriction analysis, we identified a female who demons trated heterozygosity for an unusual restriction fragment caused by the los s of a CfoI restriction site. Sequence analysis of the apo E gene was perfo rmed and a carrier of the mutant allele with C --> T substitution at cDNA p osition 3817 was identified, which caused an Arg136 --> Cys change. The fir st-line relatives have been screened for this rare mutation with PCR and re striction analysis of PCR products. The complete lipoprotein parameters hav e been determined in the probands family. In the family, only one child had the same mutant allele as his mother had. The proband (7.49 mmol/l) with h er siblings had hypercholesterolemia and a high body mass index (BMI 31.6 k g/m(2)). By contrast, her son had a normal lipid spectrum with normal BMI. We described the mutation apo E2* (Arg136 --> Cys) in a family with elevate d lipid levels, but there was no confirmation of the connection between thi s mutation and type III hyperlipoproteinemia or hyperlipoproteinemia at all . In the case of this mutation, other factors (mainly genetic) are importan t for the development of lipid metabolism disorders.