Mutation H63D in the HFE gene confers risk for the development of type 2 diabetes mellitus but not for chronic complications.
OBJECTIVE
To evaluate the frequency of mutations in the HFE gene (C282Y and H63D) in type 2 diabetes mellitus (DM) patients and their possible association with diabetic chronic complications.


METHODS
A case-control study with 723 subjects was performed. All diabetic subjects (n=519) underwent a clinical and laboratory evaluation. Diabetic retinopathy (DR) was evaluated by an ophthalmologist. Diabetic nephropathy (DN) was categorized by urinary albumin excretion (UAE) as normoalbuminuria (n=247), microalbuminuria (n=68), macroalbuminuria (n=70), or the presence of end-stage renal disease (dialysis; n=134). Data available for blood donors (n=204) were limited to age, sex, body mass index, and absence of previous diagnosis of diabetes and normal fasting plasma glucose. The mutations C282Y and H63D in the HFE gene were genotyped based on PCR protocols and digested with the restriction enzymes SnabI (C282Y) and MboI (H63D).


RESULTS
There was an association of type 2 DM with H63D polymorphism (genotypes HD/DD: OR=1.7, 95% CI=1.2-2.6), but not with C282Y polymorphism (OR=0.7, 955 CI=0.4-1.4). In respect to the chronic complications, there was no difference in the prevalence of DR, DN, or ischemic heart disease among the different genotypes.


CONCLUSIONS
Mutation H63D in the HFE gene was associated with a higher risk of type 2 DM, but did not appear to confer risk for diabetic chronic complications. The mutation C282Y was not associated with diabetes or its chronic complications.
Colli
Máikel L
ML
Endocrine Division, Hospital de Clinicas de Porto Alegre, Federal University of Rio Grande do Sul, Porto Alegre, Brazil. maikelcolli@yahoo.com.br
Gross
Jorge L
JL
Canani
Luis H
LH
D000368:Aged; D000483:Alleles; D001786:Blood Glucose / Q000032:analysis; D001938:Brazil; D016022:Case-Control Studies; D048909:Diabetes Complications / Q000235:genetics*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000235:genetics*; D005215:Fasting; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I / Q000235:genetics*; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000235:genetics*; D008875:Middle Aged; D009154:Mutation / Q000235:genetics*
D001786:Blood Glucose; C103673:HFE protein, human; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I; D008565:Membrane Proteins