The Finland-United States Investigation of Non-Insulin-Dependent
Diabetes Mellitus Genetics (FUSION) Study. II. An Autosomal Genome
Scan for Diabetes-Related Quantitative-Trait Loci

Type 2 diabetes mellitus is a complex disorder encompassing multiple metabolic
defects.  We report results from an autosomal genome scan for type 2 diabetes-
related quantitative traits in 580 Finnish families ascertained for an
affected sibling pair and analyzed by the variance components-based
quantitative-trait locus (QTL) linkage approach.  We analyzed diabetic and
nondiabetic subjects separately, because of the possible impact of disease
on the traits of interest.  In diabetic individuals, our strongest results
were observed on chromosomes 3 (fasting C-peptide/glucose: maximum LOD score
[MLS]=3.13 at 53.0 cM) and 13 (body-mass index: MLS=3.28 at 5.0 cM).  In
nondiabetic individuals, the strongest results were observed on chromosomes
10 (acute insulin response: MLS=3.11 at 21.0 cM), 13 (2-h insulin: MLS=2.86
at 65.5 cM), and 17 (fasting insulin/glucose ratio: MLS=3.20 at 9.0 cM).  In
several cases, there was evidence for overlapping signals between diabetic
and nondiabetic individuals; therefore we performed joint analyses.  In these
joint analyses, we observed strong signals for chromosomes 3 (body-mass
index: MLS=3.43 at 59.5 cM), 17 (empirical insulin-resistance index:
MLS=3.61 at 0.0 cM), and 19 (empirical insulin-resistance index: MLS=2.80
at 74.5 cM).  Integrating genome-scan results from the companion article by
Ghosh et al., we identify several regions that may harbor susceptibility
genes for type 2 diabetes in the Finnish population.