Identification of an apoC-II variant (apoC-IIBethesda) in a kindred with apoC-II deficiency and type I hyperlipoproteinemia.
Apolipoprotein (apo) C-II deficiency is characterized by elevated plasma triglycerides, chylomicrons, and very low density lipoproteins, as well as reduced levels of low density and high density lipoproteins. A subject with apoC-II deficiency has been identified with an apoC-II plasma level of less than 0.05 mg/dl. The plasma apoC-II in the proband was immunochemically similar to apoC-II in normal subjects when analyzed by Ouchterlony immunodiffusion, however the apoC-II had an apparently lower molecular weight and higher pI when analyzed by two-dimensional gel electrophoresis. This apoC-II variant, designated apoC-IIBethesda, was not affected by neuraminidase treatment or reduction. Two-dimensional gel electrophoresis of the plasma of the mother of the proband revealed both normal apoC-II and apoC-IIBethesda, whereas analysis of the father and two siblings revealed apoC-II of normal electrophoretic mobility. These results were interpreted as indicating that the proband was a compound heterozygote with one allele for apoC-IIBethesda inherited from the mother and an allele coding for an abnormality which results in the virtual or complete absence of plasma apoC-II from the father. This proband represents the first example of a compound heterozygote for an apolipoprotein defect associated with a dyslipoproteinemia.
Sprecher
D L
DL
National Heart, Lung, and Blood Institute, Molecular Disease Branch, Bethesda, MD 20892.
Taam
L
L
Gregg
R E
RE
Fojo
S S
SS
Wilson
D M
DM
Kashyap
M L
ML
Brewer
H B
HB
D053304:Apolipoprotein C-II; D001056:Apolipoproteins C / Q000172:deficiency* / Q000235:genetics; D002648:Child; D005260:Female; D006801:Humans; D008072:Hyperlipoproteinemia Type I / Q000235:genetics*; D006951:Hyperlipoproteinemias / Q000235:genetics*; D008075:Lipoproteins, HDL / Q000172:deficiency* / Q000235:genetics
D053304:Apolipoprotein C-II; D001056:Apolipoproteins C; D008075:Lipoproteins, HDL