Molecular genetic studies of GPIHBP1. A) DNA sequence analysis of GPIHBP1 exon 2 from genomic DNA of a normolipidemic subject (upper tracing), a G56R heterozygote (middle tracing) and the homozygote proband (lower tracing). For each tracing, normal nucleotide sequence is shown in the top line of letters, with single letter amino acid codes and codon numbers beneath. The position of the mutated nucleotide is indicated by the arrow. B) Evolutionary conservation of human GPIHBP1 G56 in primates and rodents; the single letter amino acid codes and peptide position for the homologous region from each species are shown. C) Nuclear family of the proband with severe type V hyperlipoproteinemia and fasting chylomicronemia. The proband (identification [ID] number II-3) and her older affected brother (ID II-1) are indicated with solid symbols. Genotype-proven heterozygotes are shown with half-solid symbols. Patient age and plasma concentrations of total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C), all in millimoles per litre (mM), and of apolipoprotein (apo) A-I and B, in grams per litre (g/L), are shown. ND means the value could not be determined. A documented history of hospitalization for pancreatitis and coronary heart disease (CHD) are shown. Genotypes of the GBPHBP1 exon 2 G56R mutation and of common APOE isoforms are shown.