Genetic Overlap Between Alzheimer’s Disease and Bipolar Disorder Implicates the MARK2 and VAC14 Genes

Background: Alzheimer's disease (AD) and bipolar disorder (BIP) are complex traits influenced by numerous common genetic variants, most of which remain to be detected. Clinical and epidemiological evidence suggest that AD and BIP are related. However, it is not established if this relation is of genetic origin. Here, we applied statistical methods based on the conditional false discovery rate (FDR) framework to detect genetic overlap between AD and BIP and utilized this overlap to increase the power to identify common genetic variants associated with either or both traits. Methods: We obtained genome wide association studies data from the International Genomics of Alzheimer's Project part 1 (17,008 AD cases and 37,154 controls) and the Psychiatric Genetic Consortium Bipolar Disorder Working Group (20,352 BIP cases and 31,358 controls). We used conditional QQ-plots to assess overlap in common genetic variants between AD and BIP. We exploited the genetic overlap to re-rank test-statistics for AD and BIP and improve detection of genetic variants using the conditional FDR framework. Results: Conditional QQ-plots demonstrated a polygenic overlap between AD and BIP. Using conditional FDR, we identified one novel genomic locus associated with AD, and nine novel loci associated with BIP. Further, we identified two novel loci jointly associated with AD and BIP implicating the MARK2 gene (lead SNP rs10792421, conjunctional FDR=0.030, same direction of effect) and the VAC14 gene (lead SNP rs11649476, conjunctional FDR=0.022, opposite direction of effect). Conclusions: We found polygenic overlap between AD and BIP and identified novel loci for each trait and two jointly associated loci. Further studies should examine if the shared loci implicating the MARK2 and VAC14 genes could explain parts of the shared and distinct features of AD and BIP

Characterization of vacuum bottoms from the P-99 coal liquefaction unit

A composite sample of vacuum bottoms has been analyzed by structural sensitive techniques applicable to high molecular weight, highly functional coal-derived materials. The utilization and limitations of x-ray diffraction, infrared, high resolution and /sup 13/C-CP/MAS nuclear magnetic resonance, high resolution and field ionization mass spectrometry, and electron spin resonance are discussed. Particular emphasis is given to the characterization of methylene chloride soluble fractions, isolated by a combination of mild extraction and functionality-specific procedures, in terms of heteroatom functionality, molecular weight and carbon number distributions, and mean structural parameters. This nondistillate but soluble material is primarily a complex mixture of high molecular weight polynuclear aromatic and heterocyclic components with short alkyl substituents. The vacuum bottoms are low in phenolic OH functionality compared to typical SRC-II distillates. 9 references, 25 figures, 14 tables