Building Bridges Toward Science Careers for Youth with Disabilities

Several researchers have addressed the issue of accommodating students with disabilities in college science classrooms (Brazier, Parry, & Fischbach, 2000; Womble & Walker, 2001). However, little research has focused on the types of accommodations and supports needed for students with disabilities at the college level (Stodden, 2000). This brief outlines results of research conducted by the Bridges Project funded by the National Science Foundation Program for Persons with Disabilities. The major goals of the project were (a) to create a model facilitating greater access for students with disabilities to postsecondary education and careers in science and technology, and (b) to investigate issues related to the transition from high school to college for students with disabilities

Analysis of somatic hypermutation in X-linked hyper-IgM syndrome shows specific deficiencies in mutational targeting

Subjects with X-linked hyper-IgM syndrome (X-HIgM) have a markedly reduced frequency of CD27+ memory B cells, and their Ig genes have a low level of somatic hypermutation (SHM). To analyze the nature of SHM in X-HIgM, we sequenced 209 nonproductive and 926 productive Ig heavy chain genes. In nonproductive rearrangements that were not subjected to selection, as well as productive rearrangements, most of the mutations were within targeted RGYW, WRCY, WA, or TW motifs (R = purine, Y = pyrimidine, and W = A or T). However, there was significantly decreased targeting of the hypermutable G in RGYW motifs. Moreover, the ratio of transitions to transversions was markedly increased compared with normal. Microarray analysis documented that specific genes involved in SHM, including activation-induced cytidine deaminase (AICDA) and uracil-DNA glycosylase (UNG2), were up-regulated in normal germinal center (GC) B cells, but not induced by CD40 ligation. Similar results were obtained from light chain rearrangements. These results indicate that in the absence of CD40-CD154 interactions, there is a marked reduction in SHM and, specifically, mutations of AICDA-targeted G residues in RGYW motifs along with a decrease in transversions normally related to UNG2 activity