BMBB

Spinocerebellar ataxia type 1 (SCA1) is an autosomal dominant neurodegenerative disease resulting from an expanded CAG repeat in the SCA1 gene that leads to an expanded polyglutamine tract in the gene product. Previous studies have demonstrated that serine at site 776 is phosphorylated [E.S. Emiamian, M.D. Kaytor, L.A. Duvick, T. Zu, S.K. Tousey, H.Y. Zoghbi, H.B. Clark, H.T. Orr, Serine 776 of ataxin-1 is critical for polyglutamine-induced disease in SCA1 transgenic mice, Neuron 38 (2003) 375-387.]. Studies of ataxin-1 S776 and serine mutated to an alanine, A776, have also shown differential protein-protein interactions and reduced neurodegeneration [H.K. Chen, P. Fernandez-Funez, S.F. Acevedo, Y.C. Lam, M.D. Kaytor, M.H. Fernandez, A. Aitken, E.M. Skoulakis, H.T. Orr, J. Botas, H.Y. Zoghbi, Interaction of Akt_phosphorylated ataxin-1 with 14-3-3 mediates neurodegeneration in spinocerebellar ataxia type 1.]. However, mutation of the site serine 776 to an alanine did not abolish all ...

The killer cell immunoglobulin-like receptors (KIR) mediate human natural killer (NK) cell cytotoxicity via activating or inhibiting signals. Although informative and functional haplotype patterns have been reported, most genotyping has been performed at resolutions that are structurally ambiguous. In order to leverage structural information given low-resolution genotypes, we performed experiments to quantify the effects of population variations, reference haplotypes, and genotyping resolutions on population-level haplotype frequency estimations as well as predictions of individual haplotypes. We genotyped 10,157 unrelated individuals in 5 populations (518 African American[AFA], 258 Asian or Pacific Islander[API], 8,245 European[EUR], 1,073 Hispanic[HIS], and 63 Native American[NAM]) for KIR gene presence/absence (PA), and additionally half of the AFA samples for KIR gene copy number variation (CNV). A custom EM algorithm was used to estimate haplotype frequencies for each populatio...

Disparities in survival after allogeneic hematopoietic cell transplantation have been reported for some race and ethnic groups despite comparable HLA matching. Individuals' ethnic and race groups, as reported through self-identification, can change over time due to multiple sociological factors. We studied the effect of two measures of genetic similarity in 1,378 recipients who underwent myeloablative first allogeneic hematopoietic cell transplantation between 1995 and 2011 and their unrelated 10-of-10 HLA-A, -B, -C, -DRB1 and DQB1 matched donors. The studied factors were: i) Donor and recipient genetic ancestral admixture, and ii) Pairwise donor/recipient genetic distance. Increased African genetic admixture for either transplant recipients or donors was associated with increased risk of overall mortality (HR=2.26, p=0.005 and HR=3.09, p=0.0002 respectively), Transplant Related Mortality (HR=3.3, p=0.0003 and HR=3.86, p=0.0001 respectively) and decreased Disease Free Survival (...

The HLA gene complex on human chromosome 6 is one of the most polymorphic regions in the human genome and contributes in large part to the diversity of the immune system. Accurate typing of HLA genes with short-read sequencing data has historically been difficult due to the sequence similarity between the polymorphic alleles. Here, we introduce an algorithm, xHLA, that iteratively refines the mapping results at the amino acid level to achieve 99-100% four-digit typing accuracy for both class I and II HLA genes, taking only [Formula: see text]3 min to process a 30× whole-genome BAM file on a desktop computer.

The killer cell immunoglobulin-like receptor (KIR) region of human chromosome 19 contains up to sixteen genes for natural killer (NK) cell receptors that recognize human leukocyte antigen (HLA)/peptide complexes and other ligands. The KIR proteins fulfill functional roles in infections, pregnancy, autoimmune diseases, and transplantation. However, their characterization remains a constant challenge. Not only are the genes highly homologous due to their recent evolution by tandem duplications, but the region is structurally dynamic due to frequent transposon-mediated recombination. A sequencing approach that precisely captures the complexity of KIR haplotypes for functional annotation is desirable. We present a unique approach to haplotype the KIR loci using Single Molecule, Real-Time (SMRT) Sequencing. Using this method, we have for the first time comprehensively sequenced and phased sixteen KIR haplotypes from eight individuals without imputation. The information revealed four nove...