A form of familial hypobetalipoproteinaemia not due to a mutation in the apolipoprotein B gene.
Familial hypobetalipoproteinaemia (FHBL) is a dominant disorder of lipoprotein metabolism characterized by levels of apolipoprotein B-carrying lipoproteins (VLDL, IDL and LDL) which are 50% of the normal levels in the heterozygotes and almost absent in the homozygotes. Several reports have recently shown that the underlying defect in FHBL involves different mutations in the apo B gene which lead to reduced levels of apo B mRNA or to the production of truncated forms of apo B having either a lower synthetic rate or a higher catabolic rate than normal apo B. We here present a three-generation family with several FHBL members in which the linkage analysis shows absence of co-segregation between apo B gene alleles and the hypocholesterolaemic phenotype. We conclude that a dominantly transmitted mutation in a gene other than that for apo B is responsible for the low plasma cholesterol levels.
Fazio
S
S
Instituto di Terapia Medica Sistematica, Universita La Sapienza, Rome, Italy.
Sidoli
A
A
Vivenzio
A
A
Maietta
A
A
Giampaoli
S
S
Menotti
A
A
Antonini
R
R
Urbinati
G
G
Baralle
F E
FE
Ricci
G
G
D000328:Adult; D001055:Apolipoproteins B / Q000235:genetics*; D015139:Blotting, Southern; D002648:Child; D002874:Chromosome Mapping; D005260:Female; D005799:Genes, Dominant; D008040:Genetic Linkage; D006801:Humans; D006995:Hypobetalipoproteinemias / Q000097:blood / Q000235:genetics*; D008055:Lipids / Q000097:blood; D008074:Lipoproteins / Q000097:blood; D008297:Male; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*; D010375:Pedigree
D001055:Apolipoproteins B; D008055:Lipids; D008074:Lipoproteins