Endocrine Abstracts

A 59 year old man was referred to our endocrine service for persistently elevated prolactin levels. He did not report any headache, visual disturbance or galactorrhoea. He was diagnosed with schizophrenia in 1994 and was tried on different antiphychotic drugs until established on a combination of Amisulpride and Clozapine 11 years later. For the past years, his prolactin levels had been elevated ranging from 1477 to 1972 milliunit/L [60–300]. Further history revealed that he had been found to have mild normocytic normochromic anaemia for which no cause had been identified. On direct questioning, the patient reported erectile dysfunction and loss of morning erections. He had not been sexually active since 1993. In addition, he had a history of un-provoked deep venous thrombosis and pulmonary embolism, hyperlipidaemia and diabetes mellitus type 2. Physical examination showed a pale and tall man with central obesity and scanty body and facial hair. There was no gynaecomastia on breast examination. Testicular examination was not performed initially. Blood results showed a prolactin level of 1199 milliunit/L [60–300] negative for macroprolactin, total testosterone of 1.7 nmol/L [10–30], LH of 11.5 IU/L [2–12] and FSH of 28.6 IU/L [1.7–8]. A diagnosis of primary hypogonadism was made and chromosome analysis revealed 47,XXY consistent with Klinefelter syndrome. Transdermal testosterone replacement was commenced and both testosterone and haemoglobin fully normalised. This case illustrates several points. Firstly, the diagnosis of Klinefelter syndrome may be missed due to very variable phenotypical presentations. Secondly, testosterone deficiency can be a cause of unexplained anaemia. Thirdly, patients with Klinefelter syndrome can develop different co-morbidities later in life that are unrelated to testosterone deficiency. These include pulmonary diseases, thromboembolic disease, cancers and diabetes mellitus. Also, the risk of psychosis, autism and ADHD appears to be increased in patients with Klinefelter syndrome.