title: Rapid molecular diagnosis of ataxia-telangiectasia by optimised RT-PCR and direct sequencing analysis.
abstract: Ataxia-telangiectasia (A-T) is a severe autosomal recessive disorder involving cerebellar degeneration, immunodeficiency, chromosomal instability, radiosensitivity, and cancer predisposition. A-T results from mutations in a single gene (ataxia-telangiectasia mutated, ATM) on chromosome 11 that encodes a 3056 amino acid protein (ATM). The purpose of this study is the design of an easy and rapid method for the molecular diagnosis of A-T which could be applied to clinical diagnosis, genetic counselling, carrier prediction, and prenatal diagnosis. Sixteen primer pairs were designed for RT-PCR. The PCR conditions were optimised to obtain a unique profile for the amplification of the 16 PCR products. These fragments were purified, directly sequenced and interpreted. The mutations found in three Spanish A-T families were reconfirmed with the optimised PCR and direct sequencing analysis. Up to now more than 400 A-T associated mutations have been reported in the ATM gene that do not support the existence of one or several hotspots. The immense size (transcript with 9168 nucleotides) and the structure of this gene (66 exons) greatly complicate the process of screening for all sequence variations. Our simple method allows identification of mutations in the coding region of the ATM gene from cDNA and represents a very useful tool for early diagnosis and genetic counselling in families with A-T.
authors.affiliation: Servicio de Inmunologiá, Hospital Universitario 12 de Octubre, Ctra. Andalucia km 5.4, 28041-Madrid, Spain.
authors.forename: Esther
authors.initials: E
authors.lastname: Mancebo
authors.forename: Arantza
authors.initials: A
authors.lastname: Pacho
authors.forename: Paloma
authors.initials: P
authors.lastname: de Pablos
authors.forename: Jorge
authors.initials: J
authors.lastname: Muñoz-Robles
authors.forename: M José
authors.initials: MJ
authors.lastname: Castro
authors.forename: Eva
authors.initials: E
authors.lastname: Romo
authors.forename: Pablo
authors.initials: P
authors.lastname: Morales
authors.forename: Luis
authors.initials: L
authors.lastname: González
authors.forename: Estela
authors.initials: E
authors.lastname: Paz-Artal
authors.forename: Luis M
authors.initials: LM
authors.lastname: Allende
mesh_terms: D001260:Ataxia Telangiectasia / Q000175:diagnosis* / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D009154:Mutation; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013030:Spain