Endocrine Abstracts

We presented the case of a 21 years old patient, derived from Primary Care to evaluate low testosterone levels (total testosterone (TT) 0.44 ng/ml). His father had delayed pubety and his mother menarche was at 11 years. No other personal history of interest. He had adequate child development and vaccination. No parotiditis. He referred some morning erections. Weight 59 kg, size 171 cm and BMI 20.17 kg/m². Testes volume (TV) of 4-5 cc, scanty pubic hair. Tanner stage 1-2. No dysmorphic features. We repeated blood test: TT 0.20 ng/ml, sex hormone binding protein (SHBG) 89.8 nmol/l, follicule stimulation hormone (FSH) and lutein hormone (LH) inappropriately low. He had normal basal pituitary hormones. His bone age was according. Testicular and abdomen ultrasound were normal and karyotype was 46XY.Pituitary MRI showed normal hyphofysis. Smell test showed no alteration. We proposed a differential diagnosis between delayed puberty or hypogonadotropic hypogonadism. We started treatment with low doses of human chorionic gonadotropin (HCG), 1000 ui 3 days a week. After 3 months of treatment, he had TV 8-10 cc, greater development of secondary sexual characteristics. TT 8.57 ng/ml, SHBG 52.7 nmol/l. Treatment was maintained six months. At that time he had TV of 10-12 cc, greater development of total muscle mass. TT 4.19 ng/ml, SHBG 39.1 nmol/l. Spermiogram persisted in cryptospornozoospermia hypospermia. According to TT levels we suspended HCG treatment and schedule a blood test control to assess testosterone levels without stimulation. After 3 months without any medication TT levels had decreased again below normal range (1.25 ng/ml). This fact guided us towards the need for definitive treatment with testosterone. We started replacement with low dose of cypionate testosterone and progressive increase. Currently he had good testosterone levels with the substitution treatment. Genetic study for possible mutations had showed a variant in heterozygosis described as of uncertain clinical significance c.566G>A (p.Arg189His) in the FGFR1 gene. The study made to his parents showed that his mother is a carrier of the same variant. To date and due to the lack of evidence linking this variant with pathology to be inherited from an apparently healthy parent, it is probably an inherited polymorphism. It should be noted that the existing bibliography recommends reanalyzing the existence of a less defined phenotype of the parent carrier to rule out causality. This study does not rule out the genetic origin of the process or the consequent risk of repetition.