Identification and characterization of the first Spanish familial ligand-defective apolipoprotein B homozygote

BACKGROUND: Familiar ligand-defective apolipoprotein B 100 (FDB) is an auto somal inherited disease due to mutations on apo B 100, clinically indisting uishable from familial hypercholesterolemia (FH). We described the first Sp anish homozygote for FDB. METHODS: We have screened R3500Q mutation of ape 8 gene (PCR-SSCP analysis) in a large family with FDB and have identified the first Spanish homozygot e for FDB. RESULTS: The homozygote is a 58 year-old man with coronary heart disease, n o presence of xanthomata and with total cholesterol and LDL cholesterol pla sma levels of 415 and 352 mg/dl, The response to statins and resins was up to 42% for total cholesterol and 51% for LDLc plasma values, The LDL recept or activity was normal in the FDB homozygote. CONCLUSIONS: We have identified and characterised the first Spanish homozyg ote for FDB (R3500Q mutation). Our data indicate a moderate lipoprotein phe notype in FDB homozygote, different as expected comparing to homozygous FH.