Genetic heterogeneity of XY gonadal dysgenesis (Swyer syndrome): H-Y antigen-negative XY gonadal dysgenesis associated with inflammatory bowel disease

A 16 1/2-year-old girl was studied because of ileitis, lack of pubertal development, and primary amenorrhea. She had a 46,XY chromosome constitution in lymphocytes in fibroblasts without structural defects of X or Y. She was H-Y antigen negative. This observation supports the concept of causal heterogeneity of XY gonadal dysgenesis (Swyer syndrome). Two groups have been established: (1) H-Y antigen-positive forms, which are more common, possibly due to gonad-specific receptor defects (total failure or reduced receptor affinity), (2) H-Y antigen-negative forms possibly due to mutation in the H-Y generating system, either of the structural gene (presumably autosomal) or of a controlling gene (on the sex chromosomes). The H-Y antigen status may be of value in determining which patients are at risk for gonadoblastoma or dysgerminoma.