Ataxia-telangiectasia: identification and detection of founder-effect mutations in the ATM gene in ethnic populations.

To facilitate the evaluation of ATM heterozygotes for susceptibility to other diseases, such as breast cancer, we have attempted to define the most common mutations and their frequencies in ataxia-telangiectasia (A-T) homozygotes from 10 ethnic populations. Both genomic mutations and their effects on cDNA were characterized. Protein-truncation testing of the entire ATM cDNA detected 92 (66%) truncating mutations in 140 mutant alleles screened. The haplotyping of patients with identical mutations indicates that almost all of these represent common ancestry and that very few spontaneously recurring ATM mutations exist. Assays requiring minimal amounts of genomic DNA were designed to allow rapid screening for common ethnic mutations. These rapid assays detected mutations in 76% of Costa Rican patients (3), 50% of Norwegian patients (1), 25% of Polish patients (4), and 14% of Italian patients (1), as well as in patients of Amish/Mennonite and Irish English backgrounds. Additional mutations were observed in Japanese, Utah Mormon, and African American patients. These assays should facilitate screening for A-T heterozygotes in the populations studied

Treatment and management of primary antibody deficiency: German interdisciplinary evidence‐based consensus guideline

This evidence‐based clinical guideline provides consensus‐recommendations for the treatment and care of patients with primary antibody deficiencies (PADs). The guideline group comprised 20 clinical and scientific expert associations of the German, Swiss, and Austrian healthcare system and representatives of patients. Recommendations were based on results of a systematic literature search, data extraction, and evaluation of methodology and study quality in combination with the clinical expertise of the respective representatives. Consensus‐based recommendations were determined via nominal group technique. PADs are the largest clinically relevant group of primary immunodeficiencies. Most patients with PADs present with increased susceptibility to infections, however immune dysregulation, autoimmunity, and cancer affect a significant number of patients and may precede infections. This guideline therefore covers interdisciplinary clinical and therapeutic aspects of infectious (e.g., antibiotic prophylaxis, management of bronchiectasis) and non‐infectious manifestations (e.g., management of granulomatous disease, immune cytopenia). PADs are grouped into disease entities with definitive, probable, possible, or unlikely benefit of IgG‐replacement therapy. Summary and consensus‐recommendations are provided for treatment indication, dosing, routes of administration, and adverse events of IgG‐replacement therapy. Special aspects of concomitant impaired T‐cell function are highlighted as well as clinical data on selected monogenetic inborn errors of immunity formerly classified into PADs (APDS, CTLA‐4‐, and LRBA‐deficiency)