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

Familial ligand-defective apolipoprotein B 100 (FDB) is an autosomal inherited disease due to mutations on apo B 100, clinically indistinguishable from familial hypercholesterolemia (FH). We described the first Spanish homozygote for FDB.

We have screened R3500Q mutation of apo B gene (PCR-SSCP analysis) in a large family with FDB and have identified the first Spanish homozygote for FDB.

The homozygote is a 58 year-old man with coronary heart disease, no presence of xanthomata and with total cholesterol and LDL cholesterol plasma 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 receptor activity was normal in the FDB homozygote.

We have identified and characterised the first Spanish homozygote for FDB (R3500Q mutation). Our data indicate a moderate lipoprotein phenotype in FDB homozygote, different as expected comparing to homozygous FH.