493 research outputs found
A custom capture sequence approach for oculocutaneous albinism identifies structural variant alleles at the OCA2 locus
Oculocutaneous albinism (OCA) is a heritable disorder of pigment production that manifests as hypopigmentation and altered eye development. Exon sequencing of known OCA genes is unsuccessful in producing a complete molecular diagnosis for a significant number of affected individuals. We sequenced the DNA of individuals with OCA using short-read custom capture sequencing that targeted coding, intronic and non-coding regulatory regions of known OCA genes and GWAS-associated pigmentation loci. We identified an OCA2 complex structural variant (CxSV), defined by a 143kb inverted segment reintroduced in intron 1, upstream of the native location. The corresponding CxSV junctions were observed in 11/390 probands screened. The 143kb CxSV presents in one family as a copy number variant (CNV) duplication for the 143kb region. In the remaining 10/11 families, the 143kb CxSV acquired an additional 184kb deletion across the same region, restoring exons 3–19 of OCA2 to a copy-number neutral state. Allele-associated haplotype analysis found rare SNVs rs374519281 and rs139696407 are linked with the 143kb CxSV in both OCA2 alleles. For individuals in which customary molecular evaluation does not reveal a biallelic OCA diagnosis, we recommend preliminary screening for these haplotype-associated rare variants, followed by junction-specific validation for the OCA2 143kb CxSV
Mental Health and Substance Abuse Services Preferences among American Indian People of the Northern Midwest
This study examines factors that influence preferences between traditional cultural and western mental health and substance use associated care among American Indians from the northern Midwest. Personal interviews were conducted with 865 parents/caretakers of tribally enrolled youth concerning their preferences for traditional/cultural and formal healthcare for mental health or substance abuse problems. Adults strongly preferred traditional informal services to formal medical services. In addition, formal services on reservation were preferred to off reservation services. To better serve the mental health and substance abuse treatment needs of American Indians, traditional informal services should be incorporated into the current medical model
Evaluation of variants in the selectin genes in age-related macular degeneration
<p>Abstract</p> <p>Background</p> <p>Age-related macular degeneration (AMD) is a common disease of the elderly that leads to loss of the central visual field due to atrophic or neovascular events. Evidence from human eyes and animal models suggests an important role for macrophages and endothelial cell activation in the pathogenesis of AMD. We sought to determine whether common ancestral variants in genes encoding the selectin family of proteins are associated with AMD.</p> <p>Methods</p> <p>Expression of E-selectin, L-selectin and P-selectin was examined in choroid and retina by quantitative PCR and immunofluorescence. Samples from patients with AMD (n = 341) and controls (n = 400) were genotyped at a total of 34 SNPs in the <it>SELE</it>, <it>SELL </it>and <it>SELP </it>genes. Allele and genotype frequencies at these SNPs were compared between AMD patients and controls as well as between subtypes of AMD (dry, geographic atrophy, and wet) and controls.</p> <p>Results</p> <p>High expression of all three selectin genes was observed in the choroid as compared to the retina. Some selectin labeling of retinal microglia, drusen cores and the choroidal vasculature was observed. In the genetic screen of AMD versus controls, no positive associations were observed for <it>SELE </it>or <it>SELL</it>. One SNP in <it>SELP </it>(rs3917751) produced p-values < 0.05 (uncorrected for multiple measures). In the subtype analyses, 6 SNPs (one in <it>SELE</it>, two in <it>SELL</it>, and three in <it>SELP</it>) produced p-values < 0.05. However, when adjusted for multiple measures with a Bonferroni correction, only one SNP in <it>SELP </it>(rs3917751) produced a statistically significant p-value (p = 0.0029).</p> <p>Conclusions</p> <p>This genetic screen did not detect any SNPs that were highly associated with AMD affection status overall. However, subtype analysis showed that a single SNP located within an intron of <it>SELP </it>(rs3917751) is statistically associated with dry AMD in our cohort. Future studies with additional cohorts and functional assays will clarify the biological significance of this discovery. Based on our findings, it is unlikely that common ancestral variants in the other selectin genes (<it>SELE </it>and <it>SELL</it>) are risk factors for AMD. Finally, it remains possible that sporadic or rare mutations in <it>SELE</it>, <it>SELL</it>, or <it>SELP </it>have a role in the pathogenesis of AMD.</p
C-Terminus Glycans with Critical Functional Role in the Maturation of Secretory Glycoproteins
The N-glycans of membrane glycoproteins are mainly exposed to the extracellular space. Human tyrosinase is a transmembrane glycoprotein with six or seven bulky N-glycans exposed towards the lumen of subcellular organelles. The central active site region of human tyrosinase is modeled here within less than 2.5 Å accuracy starting from Streptomyces castaneoglobisporus tyrosinase. The model accounts for the last five C-terminus glycosylation sites of which four are occupied and indicates that these cluster in two pairs - one in close vicinity to the active site and the other on the opposite side. We have analyzed and compared the roles of all tyrosinase N-glycans during tyrosinase processing with a special focus on the proximal to the active site N-glycans, s6:N337 and s7:N371, versus s3:N161 and s4:N230 which decorate the opposite side of the domain. To this end, we have constructed mutants of human tyrosinase in which its seven N-glycosylation sites were deleted. Ablation of the s6:N337 and s7:N371 sites arrests the post-translational productive folding process resulting in terminally misfolded mutants subjected to degradation through the mannosidase driven ERAD pathway. In contrast, single mutants of the other five N-glycans located either opposite to the active site or into the N-terminus Cys1 extension of tyrosinase are temperature-sensitive mutants and recover enzymatic activity at the permissive temperature of 31°C. Sites s3 and s4 display selective calreticulin binding properties. The C-terminus sites s7 and s6 are critical for the endoplasmic reticulum retention and intracellular disposal. Results herein suggest that individual N-glycan location is critical for the stability, regional folding control and secretion of human tyrosinase and explains some tyrosinase gene missense mutations associated with oculocutaneous albinism type I
Mining and validating grape (Vitis L.) ESTs to develop EST-SSR markers for genotyping and mapping
Grape expressed sequence tags (ESTs) are a new resource for developing simple sequence repeat (SSR) functional markers for genotyping and genetic mapping. An integrated pipeline including several computational tools for SSR identification and functional annotation was developed to identify 6,447 EST-SSR sequences from a total collection of 215,609 grape ESTs retrieved from NCBI. The 6,447 EST-SSRs were further reduced to 1,701 non-redundant sequences via clustering analysis, and 1,037 of them were successfully designed with primer pairs flanking the SSR motifs. From them, 150 pairs of primers were randomly selected for PCR amplification, polymorphism and heterozygosity analysis in V. vinifera cvs. Riesling and Cabernet Sauvignon, and V. rotundifolia (muscadine grape) cvs. Summit and Noble, and 145 pairs of these primers yielded PCR products. Pairwise comparisons of loci between the parents Riesling and Cabernet Sauvignon showed that 72 were homozygous in both cultivars, while 70 loci were heterozygous in at least one cultivar of the two. Muscadine parents Noble and Summit had 90 homozygous SSR loci in both parents and contained 50 heterozygous loci in at least one of the two. These EST-SSR functional markers are a useful addition for grape genotyping and genome mapping
Family History of Alcoholism and Childhood Adversity: Joint Effects on Alcohol Consumption and Dependence
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65494/1/j.1530-0277.1994.tb00085.x.pd
Nature of the 5f states in actinide metals
Actinide elements produce a plethora of interesting physical behaviors due to
the 5f states. This review compiles and analyzes progress in understanding of
the electronic and magnetic structure of the 5f states in actinide metals.
Particular interest is given to electron energy-loss spectroscopy and
many-electron atomic spectral calculations, since there is now an appreciable
library of core d -> valence f transitions for Th, U, Np, Pu, Am, and Cm. These
results are interwoven and discussed against published experimental data, such
as x-ray photoemission and absorption spectroscopy, transport measurements, and
electron, x-ray, and neutron diffraction, as well as theoretical results, such
as density-functional theory and dynamical mean-field theory.Comment: 136 pages in Word format, 29 Figures; Accepted to Reviews of Modern
Physic
High-Order SNP Combinations Associated with Complex Diseases: Efficient Discovery, Statistical Power and Functional Interactions
There has been increased interest in discovering combinations of single-nucleotide polymorphisms (SNPs) that are strongly associated with a phenotype even if each SNP has little individual effect. Efficient approaches have been proposed for searching two-locus combinations from genome-wide datasets. However, for high-order combinations, existing methods either adopt a brute-force search which only handles a small number of SNPs (up to few hundreds), or use heuristic search that may miss informative combinations. In addition, existing approaches lack statistical power because of the use of statistics with high degrees-of-freedom and the huge number of hypotheses tested during combinatorial search. Due to these challenges, functional interactions in high-order combinations have not been systematically explored. We leverage discriminative-pattern-mining algorithms from the data-mining community to search for high-order combinations in case-control datasets. The substantially improved efficiency and scalability demonstrated on synthetic and real datasets with several thousands of SNPs allows the study of several important mathematical and statistical properties of SNP combinations with order as high as eleven. We further explore functional interactions in high-order combinations and reveal a general connection between the increase in discriminative power of a combination over its subsets and the functional coherence among the genes comprising the combination, supported by multiple datasets. Finally, we study several significant high-order combinations discovered from a lung-cancer dataset and a kidney-transplant-rejection dataset in detail to provide novel insights on the complex diseases. Interestingly, many of these associations involve combinations of common variations that occur in small fractions of population. Thus, our approach is an alternative methodology for exploring the genetics of rare diseases for which the current focus is on individually rare variations
Synergies, Strengths and Challenges: Findings on Community Capability from a Systematic Health Systems Research Literature Review
Background:
Community capability is the combined influence of a community’s social systems and collective resources that can address community problems and broaden community opportunities. We frame it as consisting of three domains that together support community empowerment: what communities have; how communities act; and for whom communities act. We sought to further understand these domains through a secondary analysis of a previous systematic review on community participation in health systems interventions in low and middle income countries (LMICs).
Methods:
We searched for journal articles published between 2000 and 2012 related to the concepts of “community”, “capability/participation”, “health systems research” and “LMIC.” We identified 64 with rich accounts of community participation involving service delivery and governance in health systems research for thematic analysis following the three domains framing community capability.
Results:
When considering what communities have, articles reported external linkages as the most frequently gained resource, especially when partnerships resulted in more community power over the intervention. In contrast, financial assets were the least mentioned, despite their importance for sustainability. With how communities act, articles discussed challenges of ensuring inclusive participation and detailed strategies to improve inclusiveness. Very little was reported about strengthening community cohesiveness and collective efficacy despite their importance in community initiatives. When reviewing for whom communities act, the importance of strong local leadership was mentioned frequently, while conflict resolution strategies and skills were rarely discussed.
Synergies were found across these elements of community capability, with tangible success in one area leading to positive changes in another. Access to information and opportunities to develop skills were crucial to community participation, critical thinking, problem solving and ownership. Although there are many quantitative scales measuring community capability, health systems research engaged with community participation has rarely made use of these tools or the concepts informing them. Overall, the amount of information related to elements of community capability reported by these articles was low and often of poor quality.
Conclusions:
Strengthening community capability is critical to ensuring that community participation leads to genuine empowerment. Our simpler framework to define community capability may help researchers better recognize, support and assess it
Congenital Sensorineural Deafness in Australian Stumpy-Tail Cattle Dogs Is an Autosomal Recessive Trait That Maps to CFA10
Congenital sensorineural deafness is an inherited condition found in many dog breeds, including Australian Stumpy-tail Cattle Dogs (ASCD). This deafness is evident in young pups and may affect one ear (unilateral) or both ears (bilateral). The genetic locus/loci involved is unknown for all dog breeds. The aims of this study were to determine incidence, inheritance mechanism, and possible association of congenital sensorineural deafness with coat colour in ASCD and to identify the genetic locus underpinning this disease.A total of 315 ASCD were tested for sensorineural deafness using the brain stem auditory evoked response (BAER) test. Disease penetrance was estimated directly, using the ratio of unilaterally to bilaterally deaf dogs, and segregation analysis was performed using Mendel. A complete genome screen was undertaken using 325 microsatellites spread throughout the genome, on a pedigree of 50 BAER tested ASCD in which deafness was segregating. Fifty-six dogs (17.8%) were deaf, with 17 bilaterally and 39 unilaterally deaf. Unilaterally deaf dogs showed no significant left/right bias (p = 0.19) and no significant difference was observed in frequencies between the sexes (p = 0.18). Penetrance of deafness was estimated as 0.72. Testing the association of red/blue coat colour and deafness without accounting for pedigree structure showed that red dogs were 1.8 times more likely to be deaf (p = 0.045). The within family association between red/blue coat colour and deafness was strongly significant (p = 0.00036), with red coat colour segregating more frequently with deafness (COR = 0.48). The relationship between deafness and coat speckling approached significance (p = 0.07), with the lack of statistical significance possibly due to only four families co-segregating for both deafness and speckling. The deafness phenotype was mapped to CFA10 (maximum linkage peak on CFA10 -log10 p-value = 3.64), as was both coat colour and speckling. Fine mapping was then performed on 45 of these 50 dogs and a further 48 dogs (n = 93). Sequencing candidate gene Sox10 in 6 hearing ASCD, 2 unilaterally deaf ASCD and 2 bilaterally deaf ASCD did not reveal any disease-associated mutations.Deafness in ASCD is an incompletely penetrant autosomal recessive inherited disease that maps to CFA10
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