Preliminary study of the expression of genes connected with the orexigenic and anorexigenic system using microarray technique in anorexia nervosa.

The pathogenesis of anorexia nervosa (AN) is still poorly understood. The Diagnostic and Statistical Manual of Mental Disorders (4th edition) classification differentiates 2 AN types: the restricting type (AN-R) and the binge eating/purging type (AN-BP). We investigated 4 young women suffering from AN (2 with AN-R and 2 with AN-BP). Four women, age matched, with other psychiatric disorders (paranoid schizophrenia, adjustment disorder, mental retardation) served as the reference group. The oligonucleotide microarray method (HG-U133A, Affymetrix) was used to determine the expression profile of 13 genes connected with the orexigenic and anorexigenic system: leptin, leptin receptor-coding gene, hypocretin (orexin) receptor-coding gene, hypocretin (orexin) neuropeptide precursor-coding gene and growth hormone secretagogue receptor. A hierarchical analysis of the results showed that AN-BP and AN-R patients were grouped into different clusters. Also, expression levels of leptin receptor-coding gene showed significant differences between AN-BP and AN-R patients and between AN-R and control subjects. This preliminary study suggests that the microarray technique may contribute to elucidating molecular genetics of the pathogenesis of both types of AN.