Affiliations: Biotechnology and Genetic Engineering Department,
Jordan University of Science and Technology, P.O.Box 3030, Irbid 22110,
Jordan. E-mail: asemalkhateeb@just.edu.jo
Abstract: Hereditary HFE-linked hemochromatosis is a frequent recessive
disorder among individuals of northern European ancestry. The clinical
characteristic of this disease is the gradual accumulation of iron in internal
organs, which ultimately may lead to organ damage and death. Three allelic
variants of HFE gene have been correlated with hereditary
hemochromatosis: C282Y is significantly associated with hereditary
hemochromatosis in populations of Celtic origin, H63D and S65C are associated
with milder form of iron overload. In this study we performed mutation analysis
to identify allele frequency of the three variants of HFE gene in
Jordanian Arab population, to assess deviations of these frequencies from those
detected elsewhere, and to determine if there is an increased frequency of
these variants in a diabetic population (Type 2 diabetes) from the same area.
DNA was extracted from blood samples of 440 individuals attending King Abdullah
University Hospital for ambulatory services. We used polymerase chain reaction
(PCR) to amplify exons 2 and 4 of the HFE gene then restriction fragment
length polymorphism (RFLP) method to detect the variants. There were neither
homozygous nor heterozygous for C282Y variant. For the H63D variant, 0.68%
were homozygous and 21.1% were heterozygous. For the S65C variant, there
were no homozygous and 0.23% were heterozygous. Allelic frequencies were,
0%, 11.25%, and 0.11% for C282Y, H63D, and S65C, respectively. Our
samples were subdivided into two categories of type 2 diabetic (89 cases) and
controls (blood donors, 204 cases) and compared with regard to the H63D
variant. Both groups did not have homozygous H63D variant. H63D heterozygous in
diabetics were 23.60% and in blood donor controls 22.55%. Allelic
frequency of the mutant H63D allele was 11.80% in diabetics and 11.27%
for the blood donor controls. This is the first study to show the frequency of
the three hemochromatosis gene variants in Jordan with the interesting finding
of no C282Y allele detected in 440 samples. Additionally, no significant
difference was observed in H63D variant frequency in type 2 diabetics as
compared to controls.
