Heritability of serum iron measures in the hemochromatosis and iron overload screening (HEIRS) family study.
Heritability is the proportion of observed variation in a trait among individuals in a population that is attributable to hereditary factors. The Hemochromatosis and Iron Overload Screening family study estimated heritability of serum iron measures. Probands were HFE C282Y homozygotes or non-C282Y homozygotes with elevated transferrin saturation (TS > 50%, men; TS > 45%, women) and serum ferritin concentration (SF > 300 microg/L, men; SF > 200 microg/L, women). Heritability (h(2)) was estimated by variance component analysis of TS, natural logarithm (ln) of SF, and unsaturated iron-binding capacity (UIBC). Participants (N = 942) were 77% Caucasians, 10% Asians, 8% Hispanics, and 5% other race/ethnicities. Average age (SD) was 49 (16) years; 57% were female. For HFE C282Y homozygote probands and their family members, excluding variation due to HFE C282Y and H63D genotype and measured demographic and environmental factors, the residual h(2) (SE) was 0.21 (0.07) for TS, 0.37 (0.08) for ln SF, and 0.34 (0.08) for UIBC (all P < 0.0004 for comparisons with zero). For the non-C282Y homozygote proband group, residual h(2) was significant with a value of 0.64 (0.26) for ln SF (P = 0.0096). In conclusion, serum iron measures have significant heritability components, after excluding known genetic and nongenetic sources of variation.
McLaren
Christine E
CE
Department of Epidemiology, University of California, Irvine, California 92697-7550, USA. cmclaren@uci.edu
Barton
James C
JC
Eckfeldt
John H
JH
McLaren
Gordon D
GD
Acton
Ronald T
RT
Adams
Paul C
PC
Henkin
Leora F
LF
Gordeuk
Victor R
VR
Vulpe
Chris D
CD
Harris
Emily L
EL
Harrison
Barbara W
BW
Reiss
Jacob A
JA
Snively
Beverly M
BM
D000328:Adult; D000368:Aged; D005190:Family; D005260:Female; D005293:Ferritins / Q000097:blood* / Q000235:genetics; D006432:Hemochromatosis / Q000097:blood* / Q000235:genetics*; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I / Q000097:blood / Q000235:genetics*; D006720:Homozygote; D006801:Humans; D007501:Iron / Q000097:blood*; D019190:Iron Overload / Q000097:blood* / Q000235:genetics*; D008297:Male; D008565:Membrane Proteins / Q000097:blood / Q000235:genetics*; D008875:Middle Aged; D020125:Mutation, Missense
C103673:HFE protein, human; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I; D008565:Membrane Proteins; D005293:Ferritins; D007501:Iron