HLA haplotypes and microsatellite polymorphisms in and around the major histocompatibility complex region in a Native American population with a highprevalence of scleroderma (systemic sclerosis)

Choctaw Native Americans in southeastern Oklahoma have the highest prevalen ce of scleroderma or systemic sclerosis yet found (468/100,000). An Amerind ian HLA DR2 haplotype (DRB1*1602) was significantly associated with sclerod erma in this population in a previous study It is not known, however, if ot her disease genes are linked to this HLA haplotype. The regions flanking th e HLA loci were studied with polymorphic microsatellite markers. An extende d HLA DR2 (DRB1*1602, DQA1*0501, DQB1*0301, DPB1*1301) haplotype that inclu des the class I and III regions was identified which was significantly asso ciated with scleroderma in the Oklahoma Choctaw. No other significant assoc iations with microsatellite marker alleles immediately flanking the HLA reg ion were found.