Twin studies have been a valuable source of information about the genetic basis of complex
traits. To maximize the potential of twin studies, large, worldwide registers of data on twins …

BACKGROUND CONTEXT: Disc degeneration was commonly viewed over much of the last
century as a result of aging and “wear and tear” from mechanical insults and injuries. Thus, …

Finland, located at the edge of the inhabitable world, is one of the best-studied genetic
isolates. The characteristic features of population isolates—founder effect, genetic drift and …

Background High plasma HDL cholesterol is associated with reduced risk of myocardial
infarction, but whether this association is causal is unclear. Exploiting the fact that genotypes are …

Background Vitamin D is crucial for maintenance of musculoskeletal health, and might also
have a role in extraskeletal tissues. Determinants of circulating 25-hydroxyvitamin D …

Blood pressure is a heritable trait 1 influenced by several biological pathways and responsive
to environmental stimuli. Over one billion people worldwide have hypertension (≥140 mm …

In humans, low peak bone mass is a significant risk factor for osteoporosis. We report that
LRP5, encoding the low-density lipoprotein receptor-related protein 5, affects bone mass …

Schizophrenia is a complex disorder, caused by both genetic and environmental factors and
their interactions. Research on pathogenesis has traditionally focused on neurotransmitter …

Blood low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol
and triglyceride levels are risk factors for cardiovascular disease. To dissect the polygenic …

Reduced fecundity, associated with severe mental disorders 1 , places negative selection
pressure on risk alleles and may explain, in part, why common variants have not been found …