Urinary steroid pattern in male hypogonadotrophic hypogonadism

During clinical studies on a 34-year-old man with marked hypogonadism secondary to pituitary gonadotrophin insufficiency, an attempt was made to determine whether the testes were capable of androgen production when stimulated by exogenous chorionic gonadotrophin (A.P.L.).Androgen excretion before and after chorionic gonadotrophin administration was studied. Total and fractionated 17-ketosteroid patterns suggested a severe Leydig cell deficiency which was confirmed by testicular biopsy.Panhypopituitarism was considered excluded by a normal response to metyrapone ditartrate, by a normal serum PBI and a normal radioactive iodine uptake. Genetic disorders were likewise excluded to the extent possible by determining that the chromosome pattern was normal and by determining that no similar condition existed in another member of the same family. The association of anosmia with gonadotrophin insufficiency in this case suggests a primary disorder in the hypothalamo-mamillary-tuber cinereum area.

Venation Polymorphism and Genetic Variability in Drosophila melanogaster Loew

Experimental evidence indicates that phenocopy production may provide an inflated estimate of the importance of genetic variability and recombination in the production of venation phenodeviants.