• We previously reported a lod score of 2.3 suggesting linkage between panic disorder and the α-haptoglobin locus on chromosome 16q22 in 26 pedigrees. In the present study we tested for linkage between α-haptoglobin and panic disorder in 10 new pedigrees and excluded a gene for panic disorder from 6 centimorgans (recombination fraction, 0.06) surrounding the α-haptoglobin locus. The data were analyzed under a variety of assumptions about the transmission of panic disorder, and linkage was excluded by all genetic models but one. When lod scores from the present set of 10 pedigrees were pooled with those from the first 26, no evidence of genetic heterogeneity was found, and the maximum lod score was 0.67 at a recombination fraction of O.17. Taken as a whole, the present findings do not support the presence of a disease gene for panic disorder closely linked to the α-haptoglobin locus on chromosome 16q22.
Crowe RR, Noyes R, Samuelson S, Wesner R, Wilson R. Close Linkage Between Panic Disorder and a-Haptoglobin Excluded in 10 Families. Arch Gen Psychiatry. 1990;47(4):377–380. doi:10.1001/archpsyc.1990.01810160077011