MAPPING OF THE HUMAN ADENOSINE-A(2A) RECEPTOR GENE - RELATIONSHIP TO POTENTIAL SCHIZOPHRENIA LOCI ON CHROMOSOME 22Q AND EXCLUSION FROM THE CATCH-22 REGION

Chromosome 22 contains two potential schizophrenia loci on chromosomal regions 22q11.2 and 22q12-13. In the present study we report results from linkage mapping of the gene coding for the human A(2a) adenosine receptor (AR), which is one of two receptors mediating central nervous system effects of adenosine. From seven CEPH (Centre d'Etude du Polym orphisme Humain) families, 120 individuals were typed utilizing an int ragenic restriction fragment length polymorphism. Significant linkage was found with many markers on chromosome 22. A 10-cM 1000:1 support i nterval between markers D22S301 and D22S300 is defined on the CHLC (Co operative Human Linkage Center) framework map of chromosome 22. Locali zation of the A(2a)AR gene outside the CATCH 22 syndrome region on 22q 11.2 is demonstrated by the observation of heterozygous individuals wi th defined 2-Mb deletions from this region. Thus, the A(2a)AR gene is not the schizophrenia susceptibility gene suspected in the CATCH 22 sy ndrome region on 22q11.2, but remains a candidate for a schizophrenia susceptibility gene on 22q12-13.