Effect of Native American ancestry on iron-related phenotypes of Alabama hemochromatosis probands with HFE C282Y homozygosity.
BACKGROUND
In age-matched cohorts of screening study participants recruited from primary care clinics, mean serum transferrin saturation values were significantly lower and mean serum ferritin concentrations were significantly higher in Native Americans than in whites. Twenty-eight percent of 80 Alabama white hemochromatosis probands with HFE C282Y homozygosity previously reported having Native American ancestry, but the possible effect of this ancestry on hemochromatosis phenotypes was unknown.


METHODS
We compiled observations in these 80 probands and used univariate and multivariate methods to analyze associations of age, sex, Native American ancestry (as a dichotomous variable), report of ethanol consumption (as a dichotomous variable), percentage transferrin saturation and loge serum ferritin concentration at diagnosis, quantities of iron removed by phlebotomy to achieve iron depletion, and quantities of excess iron removed by phlebotomy.


RESULTS
In a univariate analysis in which probands were grouped by sex, there were no significant differences in reports of ethanol consumption, transferrin saturation, loge serum ferritin concentration, quantities of iron removed to achieve iron depletion, and quantities of excess iron removed by phlebotomy in probands who reported Native American ancestry than in those who did not. In multivariate analyses, transferrin saturation (as a dependent variable) was not significantly associated with any of the available variables, including reports of Native American ancestry and ethanol consumption. The independent variable quantities of excess iron removed by phlebotomy was significantly associated with loge serum ferritin used as a dependent variable (p < 0.0001), but not with reports of Native American ancestry or reports of ethanol consumption. Loge serum ferritin was the only independent variable significantly associated with quantities of excess iron removed by phlebotomy used as a dependent variable (p < 0.0001) (p < 0.0001; ANOVA of regression).


CONCLUSIONS
We conclude that the iron-related phenotypes of hemochromatosis probands with HFE C282Y homozygosity are similar in those with and without Native American ancestry reports.
Southern Iron Disorders Center, Birmingham, Alabama, USA. ironmd@dnamail.com
James C
JC
Barton
Ellen H
EH
Barton
Ronald T
RT
Acton
D000293:Adolescent; D000328:Adult; D000368:Aged; D000407:Alabama; D000428:Alcohol Drinking; D019943:Amino Acid Substitution; D005260:Female; D005293:Ferritins / Q000097:blood; D006432:Hemochromatosis / Q000175:diagnosis* / Q000208:ethnology* / Q000235:genetics; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006720:Homozygote; D006801:Humans; D007198:Indians, North American / Q000235:genetics; D007501:Iron / Q000097:blood*; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D008875:Middle Aged; D010641:Phenotype; D018962:Phlebotomy; D014168:Transferrin / Q000032:analysis
C103673:HFE protein, human; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I; D008565:Membrane Proteins; D014168:Transferrin; D005293:Ferritins; D007501:Iron