Prevalence of the Cys282Tyr and His63Asp HFE gene mutations in Spanish patients with hereditary hemochromatosis and in controls.

Background/aims: A mutation (Cys282Tyr) of the HFE gene has recently been reported to be present in most of the patients with hereditary hemochromatosis of Northern European ancestry, but in a lower frequency in Italy. No data are so far available on the prevalence of these mutations in Spain. Therefore, we initiated the present study to determine if the reported Cys282Tyr HFE mutation is also the main cause of hereditary hemochromatosis in Spain. In addition, we investigated the presence of the His63Asp HFE mutation in patients and in controls.

Methods: Thirty-one hereditary hemochromatosis patients and 485 controls were screened for the Cys282Tyr and the His63Asp mutations, using polymerase chain reaction amplification of genomic DNA, followed by digestion with the restriction enzymes Rsa I or Dpn II, respectively, and the separation of the products by electrophoresis.

Results: Twenty-seven out of 31 (87.1%) hereditary hemochromatosis patients were homozygous for the Cys282Tyr mutation. None of the patients was homozygous for the His63Asp mutation, and two patients (6.5%) were compound heterozygous (Cys282Tyr/His63Asp). Only one of 512 (0.2%) controls was homozygous for the Cys282Tyr mutation, and 29 (5.7%) were heterozygous. The Cys282Tyr mutation is present with an allelic frequency of 90.3+/-7.5% in patients with hereditary hemochromatosis and 3.0+/-1.1% in controls. Twenty out of 487 (4.1%) controls were His63Asp homozygous, while 171 (35.1%) were heterozygous. The His63Asp mutation is present with an allelic frequency of 21.7+/-2.7% in controls.

Conclusions: The high frequency of the Cys282Tyr mutation in hereditary hemochromatosis patients indicates that this mutation is the most common defect associated with hereditary hemochromatosis in Spain. The finding of some patients with the wild genotype at position 282 suggests the existence of other changes in the HFE gene or in other loci involved in the disease. We have found one of the highest allelic frequencies reported for the His63Asp mutation in our controls (21.7+/-2.7%).