Direct insertion of euchromatic material from chromosome Y in the X-chromosome in hypogonadotropic hypogonadisms with Crohn's disease.

The relationship between chromosomal abnormalities and Crohn's disease has not been established. Crohn's disease is associated with inflammation of the bowel, severe abdominal pain and chronic diarrhea. Its etiology is not known at present. A recessive gene with incomplete penetrance is thought to be a factor which does not follow simple mendelian inheritance. We report a case, where the euchromatin material of Y chromosome (p11.1 p11.2) has been directly inserted into the long arm of the X chromosome (q21.2), and is assumed to be the most likely cause of hypogonadotropic hypogonadism in this patients. It could also be that the function of the testis-determining factor (SRY) has been disrupted due to the insertion, causing loss of testicular development.