Pituitary hormone reserve in the Laurence-Moon-Bardet-Biedl syndrome

A patient who presented with hypgonadism was found to have classical features of the Laurence-Moon-Bardet-Syndrome. He had oligospermia and low serum testosterone. Basal serum thyroid stimulating hormone (TSH), prolactin (PRL), growth hormone (GH), cortisol, luteinising hormone (LH) and follicle stimulating hormone (FSH) were normal. Stimulation with thyrotropin releasing hormone. (TRH) showed normal pituitary reserve for TSH and PRL. Adequate insulin hypoglycaemia caused a normal rise of GH and cortisol. LH and FSH showed normal peaks after luteinishing hormone releasing hormone (LHRH). These results indicate normal pituitary hormone reserve and hypogonadotrophic hypgonadism secondary to hypothalamic dysfunction.