1. Al-Ayadhi LY, Ben Bacha AG, Kotb M, El-Ansary AK. {{A novel study on amyloid beta peptide 40, 42 and 40/42 ratio in Saudi autistics}}. {Behavioral and brain functions : BBF}. 2012 Jan 13;8(1):4.
ABSTRACT: Objectives: We examined whether plasma concentrations of amyloid beta (Abeta) as protein derivatives play a central role in the etiology of autistic features. Design and Methods: Concentrations of human Abeta (1-42), Abeta (1-40), and Abeta (40/42) in the plasma of 52 autistic children (aged 3-16 years) and 36 age-matched control subjects were determined by using the ELISA technique and were compared. Results: Compared to control subjects, autistic children exhibited significantly lower concentrations of both Abeta (1-40) and Abeta (1-42) and lower Abeta (40/42) concentration ratio. Receiver operating characteristics curve (ROC) analysis showed that these measurements of Abeta peptides showed high specificity and sensitivity in distinguishing autistic children from control subjects. Conclusions: Lower concentrations of Abeta (1-42) and Abeta (1-40) were attributed to loss of Abeta equilibrium between the brain and blood, an imbalance that may lead to failure to draw Abeta from the brain and/or impairment of beta- and gamma- secretase’s concentration or kinetics as enzymes involving in Abeta production.
Lien vers le texte intégral (Open Access ou abonnement)
2. Weck KE, Zehnbauer B, Datto M, Schrijver I. {{Molecular genetic testing for fragile X syndrome: laboratory performance on the College of American Pathologists proficiency surveys (2001-2009)}}. {Genetics in medicine : official journal of the American College of Medical Genetics}. 2012 Jan 5.
Purpose:The College of American Pathologists offers biannual proficiency testing for molecular analysis of fragile X syndrome. The purpose of this study was to analyze laboratory performance on the fragile X proficiency surveys from 2001 to 2009.Methods:Individual laboratory responses were analyzed for accuracy of genotype determination (normal, gray zone, premutation, or full mutation) and size analysis of the FMR1 trinucleotide repeat region. The analytical sensitivity and specificity of testing for fragile X were calculated, and laboratory performance for trinucleotide repeat sizing was evaluated.Results:Overall, laboratories demonstrated analytical sensitivity of 99% and 96% for detection of full mutations associated with fragile X syndrome in males and females, respectively; analytical sensitivity of 98% for detection of premutations; and analytical specificity of 99.9%. Size measurements of the CGG repeat region were acceptable from most laboratories, with an increase in the range of reported sizes observed for larger repeat expansions.Conclusions:Molecular genetic testing for fragile X syndrome demonstrated excellent sensitivity and specificity by laboratories participating in the College of American Pathologists (CAP) surveys. Allele sizing demonstrated good performance overall with improved accuracy over the study period. Participation in proficiency testing can aid laboratories in assessing individual performance and need for calibration of assays.Genet Med advance online publication 5 January 2012.
