Restriction digests of the clone give the following sizes (kb): EcoRI--2.95, 2.65; MluI--uncut; PstI--3.4, 1.1, 0.9; BamHI--5.6; HindIII--3.1, 2.5. This probe detects the following genomic restriction fragments (kb): NotI--775, BssHII--600; MluI--1225, 1125; NruI--700, SacII--400; SfiI--380. This clone extends from the EcoRI site at position 137 (5' untranslated region) to the 3' end at nucleotide 2788, and thus encodes a complete polypeptide. This clone lacks an alternative exon in the 5' noncoding region (249 to 324) and thus contains a HindIII site at 248. 5 of 10 cDNAs sequenced contain the alternative exon. The polymorphism has been studied using a 1.23 kb PstI fragment from the upstream non-coding and N-terminal coding sequences. In 40 CEPH families, the haplotype frequencies are as follows: A1B1--0.45; A1B2--0.1; A2B1--0.32; A2B2--0.13. There is no significant linkage disequilibrium between the two PstI polymorphisms. |
