Report Human Leukocyte Antigen in Genodermatosis z MOHAMED AMER, M.D., NAWAL AFIFI, M.D., IRENE ISKANDER, M.D., AND NACWA DIAB, M.S. z ABSTRACT: zyxwvutsrqpo Tissue typing performed on the lymphocytes of 4 1 patients, including: 23 patients with ichthyosis (15 of au- tosomal dominant and 8 of the x-linked variety; 8 patients with tuberous sclerosis fepiloia); and 10 patients with acroder- matitis enteropathica (AEP). fn addition. tissue typing wa5 zyxwvutsr per- formed for a control group of 80 healthy unrelated subjects of the same ethnic origin as the patients. A significant increase of A, antigen or its crossreacting antigen A,, was detected among the three diseases studied. A significant increase of HLA-A, antigen was found in autosomal dominant ichthyosis, while the x-linked variety showed significant association with HLA- noticed in both epiloia and A€P. The suggested mechanisms of such association may be referred to as incidental genetic link- age with mutants causing disease or deficiency. CWZ. A significant association zyxwvutsrqp with HLA-A,, antigen was The human leukocyte antigens (HLA) are glycopro- tiens on the cell surface and are expressed by almost all nucleated human cells.' These antigens differ from one person to another. There are five loci for the HLA anti- gens on the short arm of chromosome zyxwvuts 6. The loci are termed A, 6, C, D, and DR, in the order of their discov- ery, not of their location, except the latter.2 Each locus controls multiple allelic determinants, which is an indi- cation of the polymorphic character of the loci. Twenty HLA-A genes, 42 HLA-6 genes, 8 HLA-C genes, 12 HLA-D genes, and 10 HLA-DR genes are recognized in each respective IOCUS.~ Many studies have been done since 1971 on the relationship between HLA antigens and human skin diseases. The relationship between HLA and more than 50 skin diseases has been investigated, and more than 300 reports have been published.g The present study was undertaken to look for any sig- nificant association of HLA antigens with ichthyosis, epiloia, and AEP. Address for reprints: Moharned Arncr. M.D.. Department of Der- matology and Venereology. Zagazig University. Zagazlg. Egypt. From the Department of Dermatology and Venereology, Zagazig University, School of Medicine, Zagazig, Egypt and the Department of Clinical Pathology, Cairo University School of Medicine Cairo, Egypt Patients and Methods Twenty-three patients with ichthyosis (15 with au- tosornal dominant type and 8 with x-linked variety), 8 patients with epiloia, and 10 patients with AEP formed the study group. They were compared with 80 unrelated normal controls of the same ethnic origin. None of the patients studied are relatives, except for two brothers with of x-linked ichthyosis. For HLA typing, a two-step microcytotoxicity technique was used according to Terasaki et al.4 Results The results are presented in Tables 1-4. The results of HLA typing of the control group were found to be more or less parallel to the results of control studies done for the same population by Kame1 et a1.j and by Hassan." Discussion HLA-A, antigen was found to increase significantly or to crossreact with HLA-A,, in the diseases studied. A significant association with A, antigen was found in the ichthyotic group. Eight cases of autosomal dominant type also showed significant association with B,, anti- gen. Five of the eight patients had the HLA-A,. zy B,, hap- lotype and presented with atopic manifestation. 53