Hemochromatosis and iron-overload screening in a racially diverse population.
BACKGROUND
Iron overload and hemochromatosis are common, treatable conditions. HFE genotypes, levels of serum ferritin, transferrin saturation values, and self-reported medical history were studied in a multiethnic primary care population.


METHODS
Participants were recruited from primary care practices and blood-drawing laboratories. Blood samples were tested for transferrin saturation, serum ferritin, and C282Y and H63D mutations of the HFE gene. Before genetic screening, participants were asked whether they had a history of medical conditions related to iron overload.


RESULTS
Of the 99,711 participants, 299 were homozygous for the C282Y mutation. The estimated prevalence of C282Y homozygotes was higher in non-Hispanic whites (0.44 percent) than in Native Americans (0.11 percent), Hispanics (0.027 percent), blacks (0.014 percent), Pacific Islanders (0.012 percent), or Asians (0.000039 percent). Among participants who were homozygous for the C282Y mutation but in whom iron overload had not been diagnosed (227 participants), serum ferritin levels were greater than 300 mug per liter in 78 of 89 men (88 percent) and greater than 200 microg per liter in 79 of 138 women (57 percent). Pacific Islanders and Asians had the highest geometric mean levels of serum ferritin and mean transferrin saturation despite having the lowest prevalence of C282Y homozygotes. There were 364 participants in whom iron overload had not been diagnosed (29 C282Y homozygotes) who had a serum ferritin level greater than 1000 microg per liter. Among men, C282Y homozygotes and compound heterozygotes were more likely to report a history of liver disease than were participants without HFE mutations.


CONCLUSIONS
The C282Y mutation is most common in whites, and most C282Y homozygotes have elevations in serum ferritin levels and transferrin saturation. The C282Y mutation does not account for high mean serum ferritin levels and transferrin saturation values in nonwhites.
Adams
Paul C
PC
Department of Medicine, London Health Sciences Centre, London, Ont, Canada. padams@uwo.ca
Reboussin
David M
DM
Barton
James C
JC
McLaren
Christine E
CE
Eckfeldt
John H
JH
McLaren
Gordon D
GD
Dawkins
Fitzroy W
FW
Acton
Ronald T
RT
Harris
Emily L
EL
Gordeuk
Victor R
VR
Leiendecker-Foster
Catherine
C
Speechley
Mark
M
Snively
Beverly M
BM
Holup
Joan L
JL
Thomson
Elizabeth
E
Sholinsky
Phyliss
P
D001168:Arthritis / Q000209:etiology; D048909:Diabetes Complications; D005260:Female; D005293:Ferritins / Q000097:blood*; D005787:Gene Frequency; D005838:Genotype; D006331:Heart Diseases / Q000209:etiology; D006432:Hemochromatosis / Q000150:complications / Q000208:ethnology / Q000235:genetics*; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006720:Homozygote; D006801:Humans; D007501:Iron; D019190:Iron Overload / Q000097:blood / Q000453:epidemiology / Q000208:ethnology / Q000235:genetics; D008107:Liver Diseases / Q000209:etiology; D016015:Logistic Models; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D009154:Mutation; D010641:Phenotype; D017678:Sex Distribution; D014168:Transferrin / Q000032:analysis*; D014481:United States / Q000453:epidemiology
C103673:HFE protein, human; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I; D008565:Membrane Proteins; D014168:Transferrin; D005293:Ferritins; D007501:Iron