An amino acid polymorphism in histidine-rich glycoprotein (HRG) explains 59% of the variance in plasma HRG levels.
A pedigree-based maximum likelihood method developed by Lange et al. (12) was used to study the contribution of a newly defined di-allelic polymorphism in histidine-rich glycoprotein (HRG) to the plasma levels of HRG. In four families (n = 99) and 20 volunteers we found a heritability of 70%, an age effect of 3% and an effect of individual environmental factors of 27%. These results are remarkably similar to the results found in a previous parent-twin study in which a heritability of 69% and an effect of random environment of 31% was found. The overall genetic influence in the present study can be subdivided into an effect of 59% by the HRG phenotype and 11% by residual genetic factors. The influence of the HRG phenotype of 59% can entirely be explained by adding up the effect of the two alleles that make up the phenotype. These results indicate a codominant inheritance pattern of HRG levels in which the genetic influences can almost completely be ascribed to the additive effect of the di-allelic HRG locus whereas only a small part is due to other loci.
Hennis
B C
BC
Gaubius Laboratory TNO-PG, Leiden, The Netherlands.
Boomsma
D I
DI
van Boheemen
P A
PA
Engesser
L
L
Kievit
P
P
Dooijewaard
G
G
Kluft
C
C
D000483:Alleles; D000596:Amino Acids / Q000737:chemistry*; D000704:Analysis of Variance; D001798:Blood Proteins / Q000235:genetics* / Q000378:metabolism; D016022:Case-Control Studies; D002874:Chromosome Mapping; D006023:Glycoproteins / Q000097:blood / Q000235:genetics*; D006801:Humans; D016013:Likelihood Functions; D008970:Molecular Weight; D010375:Pedigree; D010641:Phenotype; D011110:Polymorphism, Genetic; D011506:Proteins / Q000235:genetics* / Q000378:metabolism; D000099053:Histidine-Rich Glycoprotein
D000596:Amino Acids; D001798:Blood Proteins; D006023:Glycoproteins; D011506:Proteins; D000099053:Histidine-Rich Glycoprotein