[Clinical and biochemical characteristics of familial ligand-defective apo B-100 in a South European population].
OBJECTIVE
To compare the lipoprotein phenotype between FDB and heterozygous familial hypercholesterolemia (FH); to study the prevalence and possible founder effect of familial ligand-defective apo B100 (FDB) in a Mediterranean population, and to analyze the clinical and biochemical characteristics of FDB patients.


METHODS
We studied 19 heterozygous FDB subjects (8 males) from 12 related families, carriers of the R3500Q mutation on the apo B gene, and 57 heterozygous FH (24 males) genetically characterized, randomly selected from a total of 213 FH. The genetic diagnosis was established with Southern blot analysis, PCR-SSCP analysis and automatic sequencing. In all subjects, plasma lipids and apolipoprotein levels were determined with standard procedures.


RESULTS
We demonstrated a founder effect for the R3500Q mutation in a geographically isolated rural area from our community. The prevalence of FDB in this area is high: 4/350. Heterozygous FDB subjects showed a statistical significantly lower prevalence of xanthomas and coronary heart disease, plasma concentrations of total and LDL cholesterol, HDL cholesterol, apo B and apo A-I values than heterozygous FH subjects.


CONCLUSIONS
A founder effect for the R3500Q mutation was found in a rural population with a high prevalence of FDB. In our population, FDB patients showed a mild clinical expression and lipoprotein phenotype compared with FH patients.
Ejarque
Ismael
I
Servicio de Endocrinología y Nutrición, Hospital Clínico Universitario, Departamento de Medicina, Universidad de Valencia, Valencia, Spain.
Real
José T
JT
Chaves
Felipe J
FJ
Blesa
Sebastián
S
González
Verónica
V
Milian
Enrique
E
Ascaso
Juan F
JF
Priego
María A
MA
Carmena
Rafael
R
D000328:Adult; D000368:Aged; D053299:Apolipoprotein B-100; D001055:Apolipoproteins B / Q000235:genetics*; D005260:Female; D018703:Founder Effect; D006801:Humans; D006938:Hyperlipoproteinemia Type II / Q000097:blood / Q000235:genetics*; D008074:Lipoproteins / Q000097:blood; D008297:Male; D019083:Mediterranean Region; D008875:Middle Aged; D009154:Mutation; D010641:Phenotype
D053299:Apolipoprotein B-100; D001055:Apolipoproteins B; D008074:Lipoproteins