Patient case (clinical description): A 19-year-old male came to clinic with some sexual concern.  He recently engaged in a relationship and is worried about the satisfaction of his girlfriend. He has a "baby face" according to his girlfriend's statement and he is not as muscular as his classmates.  On physical examination, there is some pubic hair and poorly developed secondary sexual characteristics. He is unable to detect coffee smell during the examination, but the visual acuity is normal. Ultrasound reveals the testes volume of 1-2 ml. The hormonal evaluation showed serum testosterone level of 65 ng/dL with low levels of GnRH.

Patient's own account: I'm 19 years old guy and I just went to see a doctor at the clinic after I just got with my girlfriend. I'm kinda worried because she thinks that I have a baby face and to be honest, I'm way less muscular than my classmates. I don't have much hair down there, and yes, I don't have that macho look. The doctor made me smell some coffee and I couldn't smell anything special. I also had some eyesight checkups and the doctor told me everything was normal. I got my test results back and it says: testes volume is 1-2 ml and serum testosterone level of 65 ng/dL with low GnRH levels.

Clinical trial: CYP19A1 (Cytochrome P450 Family 19 Subfamily A Member 1) Gene and Pharmacogenetics of Response to Testosterone Therapy

Eligibility criteria:
Inclusion Criteria:

          -  Male Veterans with low total testosterone (<300 ng/dl) as defined by the Endocrine
             Society, who are between 40-75 years of age.

          -  These patients must be ambulatory; and be willing and able to provide written informed
             consent.

        Exclusion Criteria:

          -  history of prostate cancer, breast cancer

          -  history of testicular disease

          -  untreated sleep apnea

          -  any ongoing illness that, in the opinion of the investigator, could prevent the
             subject from completing the study

          -  patients with a hematocrit of more than 50% (2010 Endocrine Society Guidelines)

          -  prostate-related findings of a palpable prostate nodule on exam, a serum PSA of 4.0
             ng/ml or more, International Prostate Symptom Score >8(9), urinary postvoid residual
             by ultrasound of >149 ml, or an abnormal transrectal ultrasound

          -  patients who are on androgen replacement therapy, selective androgen receptor
             modulator, or finasteride

          -  patients currently on medications that affects bone metabolism such as:

               -  estrogen

               -  the selective estrogen receptor modulator (SERM) as raloxifene

               -  use of bisphosphonates (i.e. risedronate, alendronate, zoledronic acid and
                  pamidronate)

               -  within two years of study entry

               -  aromatase inhibitors

               -  GnRH analogs

               -  glucocorticoids of at least 5 mg daily for one month or more

               -  anabolic steroids

               -  dilantin

               -  warfarin

          -  patients with diseases known to interfere with bone metabolism as hyperparathyroidism,
             untreated hyperthyroidism, osteomalacia, chronic liver disease, renal failure,
             hypercortisolism, malabsorption and immobilization

          -  those with current alcohol use of more than 3 drinks per day (62).

          -  history of documented coronary artery disease at high risk for recurrence

          -  Subjects with osteoporosis or a BMD T-score of -2.5 in the lumbar spine, total femur
             or femoral neck as well as those patients with a history of osteoporosis-related
             fractures (spine, hip or wrist) or vertebral deformities on lateral spine radiographs
             deemed as fragility fractures by the team principal investigator.

          -  history of documented coronary artery disease at high risk for recurrence, history of
             deep vein thrombosis and cerebrovascular event.
Male
Accepts Healthy Volunteers
Subject must be at least 40 Years old.
Subject must be at most 75 Years

Eligibility (NLI label): Contradiction