Antibody deficiency in patients with ataxia telangiectasia is caused by disturbed B- and T-cell homeostasis and reduced immune repertoire diversity.

Background: Ataxia telangiectasia (AT) is a multisystem DNA-repair disorder caused by mutations in the ataxia telangiectasia mutated (ATM) gene. Patients with AT have reduced B- and T-cell numbers and a highly variable immunodeficiency. ATM is important for V(D)J recombination and immunoglobulin class-switch recombination (CSR); however, little is known about the mechanisms resulting in antibody deficiency severity.

Presence of ATM protein and residual kinase activity correlates with the phenotype in ataxia-telangiectasia: a genotype-phenotype study.

Ataxia-telangiectasia (A-T) is an autosomal recessive neurodegenerative disorder with multisystem involvement and cancer predisposition, caused by mutations in the A-T mutated (ATM) gene. To study genotype-phenotype correlations, we evaluated the clinical and laboratory data of 51 genetically proven A-T patients, and additionally measured ATM protein expression and kinase activity. Patients without ATM kinase activity showed the classical phenotype.

Neuropathology in classical and variant ataxia-telangiectasia.

Ataxia-telangiectasia (A-T) is classically characterized by progressive neurodegeneration, oculocutaneous telangiectasia, immunodeficiency and elevated α-fetoprotein levels. Some patients, classified as variant A-T, exhibit a milder clinical course. In the latter patients extrapyramidal symptoms, instead of cerebellar ataxia, tend to be the dominating feature and other classical disease hallmarks, like telangiectasia, appear later or even may be absent.

Cognitive and speech-language performance in children with ataxia telangiectasia.

Objective: To describe cognitive and speech-language functioning of patients with ataxia-telangiectasia (A-T) in relation to their deteriorating (oculo)motor function.

Design: Observational case series.

Methods: Cognitive functioning, language, speech and oral-motor functioning were examined in eight individuals with A-T (six boys, two girls), taking into account the confounding effects of motor functioning on test performance.