Diagnóstico genético de fibrosis quística mediante la técnica de desnaturalización de ADN a alta resolución (HRM)

Resumo

Cystic fibrosis is the severe disease of autosomal recessive inheritance most common in caucasians, with an estimated incidence between 1/2,000 and 1/6,000 live births. This disease is caused by mutations in the CFTR gene. Almost all patients develop a chronic, progressive lung disease, which is the most common cause of morbidity and mortality. In 85% of cases there is also pancreatic dysfunction (exocrine and endocrine). The diagnosis of cystic fibrosis is essentially based on clinical history, although the etiologic diagnosis is the diagnosis at molecular level, with the identification of mutations in the CFTR gene. For this purpose, there are screening techniques that identify abnormal patterns that need to be confirmed by DNA sequencing. It is now accepted that the HRM is the most sensitive screening technique in the search for variants in the DNA sequence. Alternatively, there are diagnostic batteries currently available commercially, which identify the most common cystic fibrosis mutations with sensitivity greater than 75%. In this work we have done an analysis of the CFTR gene in cystic fibrosis patients by the screening technique based on denatured DNA at high resolution (High Resolution Melting [HRM]). In parallel, in the same patients, we have made a comparative study of the sensitivity of the HRM with two commercial test. One of the test, Devyser includes an additional battery for identification of specific mutations in the Spanish population. Results obtained indicated that HRM has a sensibility closed to 100% for the detection of mutations and polymorphisms in CFTR gene. Furthermore, HRM presented higher sensitivity than the commercial tests for molecular diagnosis of cystic fibrosis patients.