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Recently, an increasing number of susceptibility variants have been identified for complex diseases. At the same time, the concern of "missing heritability" has also emerged. There is however no unified way to assess the heritability explained by individual genetic variants for binary outcomes. A systemic and quantitative assessment of the degree of "missing heritability" for complex diseases is lacking. In this study, we measure the variance in liability explained by individual variants, which can be directly interpreted as the locus-specific heritability. The method is extended to deal with haplotypes, multi-allelic markers, multi-locus genotypes, and markers in linkage disequilibrium. Methods to estimate the standard error and confidence interval are proposed. To assess our current level of understanding of the genetic basis of complex diseases, we conducted a survey of 10 diseases, evaluating the total variance explained by the known variants. The diseases under evaluation included Alzheimer's disease, bipolar disorder, breast cancer, coronary artery disease, Crohn's disease, prostate cancer, schizophrenia, systemic lupus erythematosus (SLE), type 1 diabetes and type 2 diabetes. The median total variance explained across the 10 diseases was 9.81%, while the median variance explained per associated SNP was around 0.25%. Our results suggest that a substantial proportion of heritability remains unexplained for the diseases under study. Programs to implement the methodologies described in this paper are available at http://sites.google.com/site/honcheongso/software/varexp., (© 2011 Wiley-Liss, Inc.)

The records of 53 cats with nasopharyngeal disease were examined. Of the cats with nasopharyngeal disease, 49% had lymphosarcoma and 28% had polyps. Clinical signs in these cats were compared to 24 cats with nasal disease alone. Cats with only nasal disease more commonly had historical nasal discharge and sneeze, whereas cats with nasopharyngeal disease more often had stertorous respiration, phonation change, and typically reported less nasal discharge or sneeze. It is important to include nasopharyngeal disease in the differential diagnosis for cats with nasal discharge, sneeze, stertor, or phonation change.

If there is no evidence that a hospital is using market power to "force" its contracting physician upon patients and if the exclusive contract does not adversely affect price or quality, an exclusive arrangement should not violate the federal antitrust laws. These are the insights gained from the decision handed down by the Supreme Court in Hyde (Jefferson Parish Hospital District No. 2 v. Hyde , No. 82-1031).

If there is no evidence that a hospital is using market power to "force" its contracting physician upon patients and if the exclusive contract does not adversely affect price or quality, an exclusive arrangement should not violate the federal antitrust laws. These are the insights gained from the decision handed down by the Supreme Court in Hyde (Jefferson Parish Hospital District No. 2 v. Hyde, No. 82-1031).

Physicians excluded from hospitals by reason of exclusive contracts are increasingly challenging these arrangements under the antitrust laws. With the exception of the recent case of Hyde v. Jefferson Parish Hospital District No. 2, the cases reject antitrust attacks on exclusive contracts between hospitals and physicians.