Mutations in the gene for Bruton's tyrosine kinase (Btk) are responsible for X-linked agammaglobulinemia (XLA). Thus far, mutations in this gene have been identified based on alterations in Southern or Northern blot analysis or cDNA sequence. To permit detection of mutations in genomic DNA, we designed PCR primers to flank each of the 19 exons of Btk with splice sites. Two overlapping PCR products were employed for exons longer than 230 base pairs. Single strand conformation polymorphism (SSCP) analysis was used to screen PCR products from 30 unrelated families presumed to carry a Btk mutation. It was possible to amplify DNA in every reaction from every patient, indicating that large deletions in Btk are uncommon. Twenty three different mutations were found in 25 unrelated families, including one family in whom DNA was available from a carrier but not an affected patient. Seven mutations were single base pair substitutions resulting in premature stop codons scattered throughout the gene. Small insertions or deletions causing frameshifts and secondary premature stop codons constituted an additional seven mutations. One patient had a point mutation in the start codon and one patient had a mutation in a splice donor site. Point mutations resulting in amino acid substitutions were seen in nine patients. Northern blot analysis of RNA from three patients with premature stop codons showed an absence of Btk transcript whereas four patients with amino acid substitutions had normal amounts of transcript of normal size. These studies document the considerable variability in the Btk mutations causing XLA and they demonstrate an approach that will be useful for carrier detection as well as mutation identification.

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Paper-based Dietary Assessment questionnaire and Web-Based Dietary Assessment Questionnaire was developed as a surveillance instrument to measure dietary and physical activity behaviors in children and adolescents. But it is not known how reported food intakes by children using a Web-based version of a food frequency questionnaire compare on a paper-based version of the same questionnaire. This research used data that was collected from same the group of pre-adolescents. Using two versions of the same food frequency questionnaire, this analysis compares differences in reported intake between the two versions of instruments. This research provides a comparison of dietary eat patterns between a paper-based dietary questionnaire and a web-based of the same dietary questionnaire at elementary school of the 4 th grade students. A comparison two assessment dada was assessed by comparing food items selected on the questionnaire with food items reported from a single 24-hour recall covering the same reference period. To identify and describe the major dietary eating patterns in the WT Cheney Elementary School and South Wood Elementary of the 4 th grade students in Pine Bluff Arkansas. Fourth-grade student volunteers (N=87). The two dietary questionnaires of the instrument were first compared for all participants using analysis of variance (ANOVA) with the instruments as the grouping variable. Multiple regression analysis and analysis of covariance (ANCOVA) was also used to determine differences between instrument versions while controlling for differences related to participant. The mean weekly reported servings did not vary significantly between the two paper dietary questionnaires and web-based dietary questionnaire of the questionnaire. However, the web-based questionnaire produced lower intake estimates (after adjustment for between-school differences) for all of the food groupings. In summary, while the use of technology did not resolve reporting issues that are well known with children and the paper dietary assessment instrument questionnaire method, the potential advantages offered by technology-based methods merit continued exploration in future studies.Research Article

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