HLA Haplotypes in a Genetic Isolate in Newfoundland. A Population Showing 8% Homozygosity and a Familial Aggregate of Lymphoma and Immunodeficiency Cases

Abstract

HLA typing was performed in 384 individuals of an isolated population of 1500 people with a familial aggregate of lymphoma and immunodeficiency cases. Of the total population 85% were descendants of the founding couple. First cousin marriages were common. There was a 3-fold or higher increase of the following haplotypes as compared to the frequencies in Sheffield [England]: HLA-A28, Bw35, HLA-A28, B18, HLA-A10, B18, HLA-A2, B18, HLA-A11, Bw40 and HLA-A11, B7. The frequency of HLA-A1, B8 was low (5.4%). The most common genotype was HLA-A2, B12/A2, B12 followed by HLA-A2, B12/A28, Bw35. Thirty HLA homozygous individuals were found. Of these 15 were HLA-A2, B12/A2, B12. There were 2 possible HLA crossovers which may be confirmed and 3 postulated crossovers which can never be confirmed as 1 or both parents of the individuals in question are deceased. Some of the haplotypes could be traced back to the 1st, 2nd and 3rd generations, e.e., to the 1st half of the 19th century. No single haplotype or antigen was shared by the patients.