Human leukocyte antigen haplotypes and HFE mutations in Spanish hereditary hemochromatosis and sporadic porphyria cutanea tarda.
OBJECTIVE
It has been postulated that the HFE C282Y mutation (linked to human leukocyte antigen [HLA]-A3-B7 haplotype) is not only responsible for hereditary hemochromatosis; HLA class I alleles would also contribute to the disease pathogenesis. In addition, H63D mutation linked to HLA-A29-B44 would also be pathogenetic, particularly in the Mediterranean Basin and throughout the world. However, sporadic porphyria cutanea tarda (s-PCT) has also been linked to these HFE mutations. In the present work, we have studied HFE mutations and HLA genes to test these hypotheses.


METHODS
C282Y and H63D mutations together with HLA genetic typing have been performed in Spanish hereditary hemochromatosis (n = 98) and PCT (n = 63) patients. The etiologic fraction (delta) has been used to determine the absolute strongest gene linkage to both diseases.


RESULTS
The Spanish frequent HLA-A29-B44 haplotype is not significantly associated to the H63D mutations in hereditary hemochromatosis patients (although it is found more frequently in patients than in controls). Sporadic porphyria cutanea tarda patients do not show a significant association to H63D mutations, although it is also more frequent than in controls; however, compound H63D/C282Y subjects seem to bear a significant risk to s-PCT. Allelic C282Y (and not H63D) frequencies show a significant association with s-PCT.


CONCLUSIONS
The postulated additional risk of hereditary hemochromatosis given by class I HLA antigens may be secondary to the HFE gene linkage disequilibrium with certain class I alleles or to the existence of other neighboring genetic pathogenetic factors in our Spanish sample.
Gonzalez-Hevilla
Mario
M
Department of Immunology, Hospital 12 de Octubre, Universidad Complutense, Madrid, Spain.
de Salamanca
Rafael E
RE
Morales
Pablo
P
Martínez-Laso
Jorge
J
Fontanellas
Antonio
A
Castro
Maria José
MJ
Rojo
Ricardo
R
Moscoso
Juan
J
Zamora
Jorge
J
Serrano-Vela
Juan Ignacio
JI
Arnaiz-Villena
Antonio
A
D000483:Alleles; D000911:Antibodies, Monoclonal; D004247:DNA / Q000235:genetics; D005787:Gene Frequency / Q000235:genetics; D005819:Genetic Markers; D006680:HLA Antigens / Q000235:genetics* / Q000276:immunology; D006239:Haplotypes / Q000235:genetics*; D000071020:Hemochromatosis Protein; D006486:Hemosiderosis / Q000097:blood / Q000208:ethnology / Q000235:genetics*; D015395:Histocompatibility Antigens Class I / Q000235:genetics* / Q000276:immunology; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics* / Q000276:immunology; D009154:Mutation / Q000235:genetics; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D017119:Porphyria Cutanea Tarda / Q000097:blood / Q000208:ethnology / Q000235:genetics*; D015995:Prevalence; D013030:Spain / Q000453:epidemiology
D000911:Antibodies, Monoclonal; D005819:Genetic Markers; C103673:HFE protein, human; D006680:HLA Antigens; D000071020:Hemochromatosis Protein; D015395:Histocompatibility Antigens Class I; D008565:Membrane Proteins; D004247:DNA