Tyrosine aminotransferase and chymotrypsinogen B are linked to haptoglobin on human chromosome 16q: comparison of genetic and physical distances.
The loci for haptoglobin (HP) and tyrosine aminotransferase (TAT) are known to reside at 16q22. Chymotrypsinogen B (CTRB), which is syntenic with TAT and HP on mouse chromosome 8, has also been assigned to human chromosome 16 but has not been mapped regionally. A linkage analysis was carried out in 13 informative families using RFLPs for these three markers. For CTRB, two TaqI RFLPs with a polymorphism information content of 0.60 derived from haplotype frequencies are described. The most likely order of loci, deduced from triple informative crosses, and their map distances, obtained by pair-wise linkage analysis, are HP-7 cM-TAT-9 cM-CTRB. By pulsed-field gel electrophoresis, a physical map covering more than 2000 kb was constructed. A maximum physical distance of about 700 kb was obtained for HP and TAT, which contrasts with the genetic distance of 7 cM (approximate confidence limits 2-18 cM). CTRB is at least 800 kb away from these two markers.
D000592:Amino Acid Metabolism, Inborn Errors / Q000235:genetics; D002874:Chromosome Mapping; D002885:Chromosomes, Human, Pair 16 / Q000648:ultrastructure; D002919:Chymotrypsinogen / Q000235:genetics*; D005260:Female; D008040:Genetic Linkage; D006242:Haptoglobins / Q000235:genetics*; D006801:Humans; D008297:Male; D012150:Polymorphism, Restriction Fragment Length; D014444:Tyrosine Transaminase / Q000235:genetics*
D006242:Haptoglobins; D002919:Chymotrypsinogen; D014444:Tyrosine Transaminase