A four-year project was initiated in October, 1999, to collect 780 families containing an estimated 1,000 independent affected sibling pairs (ASPs) with a proband with recurrent major depressive disorder (MDD) with onset before age 31 and at least one sibling with recurrent MDD and onset before age 41, with extension by first-degree relationships to additional affected individuals if available. Data from family and twin studies suggest that early adult onset and recurrence of MDD are predictors of increased familial risk, with an overall relative risk to siblings (RRs) estimated at 5-8. However, genetic liability to MDD is likely to be both polygenie and heterogeneous, so that large samples will be needed to detect loci which make small contributions to risk. Power analyses demonstrate that the planned sample will have > 90% power to detect a locus associated with a locus-specific RRs = 1.3, with power dropping to 84% for RRs = 1.24 and about 50% for RR = 1.2. An efficient multistage genome scan will be carried out, beginning in the project's third year. In April, 2004, blinded clinical data and biological materials (cell cultures and DNA) will be made available through the NIMH-sponsored Center for Genetic Studies. The pedigrees collected during the project's first six months are described in more detail to illustrate the characteristics of the sample.
|Original language||English (US)|
|Number of pages||1|
|Journal||American Journal of Medical Genetics - Neuropsychiatric Genetics|
|State||Published - Aug 7 2000|
ASJC Scopus subject areas
- Neuropsychology and Physiological Psychology