Confirmation of the assignment of the Dombrock blood group locus (DO) to chromosome 12p: narrowing the boundaries to 12p12.3-p13.2.
OBJECTIVE
Antigens belonging to the Dombrock blood group system have been well characterized serologically. Despite being reasonably polymorphic, chromosomal localization of the gene controlling Dombrock expression (DO) has proved difficult. In the past, DO had been provisionally assigned to chromosomes 1 and 4; more recently, DO was provisionally assigned to chromosome 12. The current study was undertaken in an attempt to confirm or refute this latest assignment.


METHODS
DNA from a series of families segregating for DO was amplified by polymerase chain reaction and analyzed for trinucleotide or tetranucleotide repeat polymorphisms of four anonymous DNA markers (D12S1042, D12S373, D12S391, D12S372) and of the von Willebrand factor gene (VWF). Lods for or against linkage were determined between DO and each marker.


RESULTS
DO is linked to all five markers. The closest linkage was established between DO and D12S373, and DO and D12S391, with peak lods for combined paternal and maternal meioses of 7.16 at peak recombination fraction (theta) = 0.08 and 7.69 at theta = 0.08, respectively.


CONCLUSIONS
We have confirmed the assignment of the Dombrock blood group locus to chromosome 12p and have refined its regional localization to 12p12.3-p13.2.
Mauthe
J
J
Rh Laboratory, Department of Pediatrics and Child Health, University of Manitoba, Winnipeg, Manitoba, Canada.
Coghlan
G
G
Zelinski
T
T
D001789:Blood Group Antigens / Q000235:genetics*; D002874:Chromosome Mapping; D002881:Chromosomes, Human, Pair 12; D008040:Genetic Linkage; D006801:Humans
D001789:Blood Group Antigens