[Molecular analysis of the corticotropin-releasing hormone receptor type 2 gene fragment in anorexia nervosa].

Introduction: There is strong evidence for the importance of genetic factors in the aetiology of anorexia nervosa (AN). Stress factors can be also associated with the clinical manifestation of AN. The hypothalamic-pituitary-adrenal axis plays an important role in stress control. The increased activity of the hypothalamic-pituitary-adrenal axis in AN is caused by corticotropin-releasing hormone hypersecretion. CRH concentration in cerebrospinal fluid is increased in patients with AN. Intracerebral administration of CRH suppresses appetite. CRH receptor type 2 (CRHR 2) is involved in the appetite suppression effects of CRH. Thus CRHR 2 gene can be a candidate gene for AN. Three CRHR 2 splicing isoforms are known: alpha, b and g. In the hypothalamus, the main appetite control centre, only the isoform CRHR 2alpha is expressed, whose mRNA is characterised by one unique exon 1alpha.
Aim: The aim of the study was the screening for mutations in exon 1alpha of the CRHR 2 gene in patients with AN, which could play a role in the pathogenesis of the disease.
Methods: The molecular analysis has been performed in 20 patients with AN and 10 healthy controls. DNA was isolated from peripheral blood leukocytes. DNA fragments were amplified by polymerase chain reaction (PCR) and sequencing was performed.
Results: After screening, no genetic variants have been found in the analysed region, including exon 1alpha and the untranslated region, both in anorectic patients as in controls.
Conclusion: The results do not confirm the hypothesis that the analysed region of the CRHR 2 gene is involved in the pathogenesis of AN.