GENOMIC SURVEY OF BIPOLAR ILLNESS IN THE NIMH GENETICS INITIATIVE PEDIGREES - A PRELIMINARY-REPORT

Four sites collaborated with the NIMH to develop a resource for the ge netic study of bipolar (BP) illness. Common methods of ascertainment a nd assessment were developed in 1989. A series of families with a bipo lar I (BPI) proband and at least one BPI or schizoaffective, bipolar t ype (SA/BP) first-degree relative has been studied. We now report init ial data from a genomic survey with an average intermarker interval of 10 cM on 540 subjects from 97 families. This is the largest commonly ascertained and assessed linkage sample for bipolar illness reported t o date; it includes 232 subjects with BPI, 32 SA/BP, 72 bipolar II (BP II), and 88 unipolar, recurrent (UPR). Nonparametric methods of analys is were employed, with all sites using affected sib pair analysis. The strongest findings thus far appear to be on chromosomes 1, 6, 7, 10, 16, and 22. Support has also been found for some previously reported l inkages, including 21q and possibly Xq26. All these areas (as well as others) will be followed up with additional markers and further analys es. No locus tested thus far meets stringent criteria for an initial f inding of significant linkage. Am. J. Med. Genet. 74:227-237, 1997. (C ) 1997 Wiley-Liss, Inc.