This document discusses mapping complex traits related to common disorders through genome-wide association studies (GWAS). It notes that while Mendelian disorders are rare and caused by single genes, common disorders are influenced by multiple genetic and environmental factors and cluster in families. The document provides examples of GWAS studies that have identified genetic variants associated with atherosclerosis, ischemic stroke, and intracerebral hemorrhage. It distinguishes between single-gene disorders and complex disorders that have an interaction of genetic and environmental factors.

1. Mapping of complex traits
2010. 4. 9
Jei Kim, MD

2. (Adopted from Dr. T. A. Manolio’s slides)

4. GWAS in stroke fields
(Atherosclerosis 2009;207:144-149)
(BMC Med Genet 2007;8(suppl 1): S11)
(BMC Med Genet 2007;8(suppl 1): S17)

5. Inherited diseases
1. Single-gene disorders
2. Disorders having complex inheritance
- complex interaction between
1) genotype at one or more loci
2) a variety of environmental exposures

6. Mendelian disorders vs. Common disorders (ref. 2)
1. Mendelian disorders
- rare and highly heritable
- variation in single gene is both necessary and
sufficient to cause disease
2. Common disorders
- influenced by several genetic and
environmental factors (ref. 2, 3)
- cluster in families (ref. 3)