W have previously reported that we found no evidence of linkage between schizophrenia and the pseudoautosomal region of the X and Y chromosomes in our series of pedigrees.1 The pseudoautosomal region we tested is located at the telomere of the short arms. Recently, a second pseudoautosomal region has been found at the telomere of the long arms as well.2 This latter region spans over 400 kilobases in physical distance and approximately 2 centimorgans in map distance. A highly polymorphic marker, sDF-1 (DXYS154), has been identified in this region.
To search for a schizophrenia vulnerability locus in the second pseudoautosomal region, we tested for linkage to the above marker in our 12 pedigrees.1 The polymerase chain reaction conditions are essentially as those described previously.2 The models used in the linkage analyses were also the same as those previously reported,1 except that the male-to-female recombination ratio was
Wang ZW, Black DW, Andreasen N, Crowe RR. No Evidence of a Schizophrenia Locus in a Second Pseudoautosomal Region. Arch Gen Psychiatry. 1994;51(5):427. doi:10.1001/archpsyc.1994.03950050087010