DNA microsatellite and linkage analysis supports the inclusion of LOCR in the Rh blood group system.
BACKGROUND
In 1994, a new low-incidence RBC antigen called LOCR was described. It was established that RBCs expressing LOCR had altered expression of Rh antigens (c or e). Unfortunately, because of an insufficient number of informative families, it was not possible to formally assign LOCR to the Rh blood group system by serology alone.


METHODS
Genomic DNA from 19 family members segregating for LOCR was analyzed for repeat polymorphisms of the chromosome 1p microsatellite markers D1S1612, D1S1597, D1S552, D1S247, and D1S2134.


RESULTS
No evidence of recombination (in either paternal or maternal meioses) between LOCR and D1S1597, D1S552, or D1S247 was observed. Peak lods for combined paternal and maternal meioses were 2.41 for either LOCR:D1S552 or LOCR:D1S247. Lods for linkage between LOCR and D1S1597 peaked at 1.81 for maternal meioses alone.


CONCLUSIONS
With serologic methods, a peak lod of 2.107 was determined previously between LOCR and RH. In this study, DNA analysis of the only informative family (with seven children) not segregating for RH yielded a peak lod of 1.81 between LOCR and D1S1597-D1S552-D1S247. By combining the results generated by each approach (lods of 3.917), evidence has been provided that supports the placement of LOCR in the Rh blood group system.
Coghlan
Gail
G
Rh Laboratory, Department of Pediatrics and Child Health, Faculty of Medicine, University of Manitoba, 770 Bannatyne Avenue, Winnipeg, Manitoba, Canada R3E 0W3.
Zelinski
Teresa
T
D020090:Chromosome Segregation / Q000235:genetics*; D002878:Chromosomes, Human, Pair 1; D005260:Female; D008040:Genetic Linkage / Q000235:genetics*; D006801:Humans; D007519:Isoantigens / Q000235:genetics*; D008126:Lod Score; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics*; D010375:Pedigree; D011995:Recombination, Genetic; D012204:Rh-Hr Blood-Group System / Q000235:genetics*
D007519:Isoantigens; C088061:LOCR, red cell antigen; D012204:Rh-Hr Blood-Group System