Endocrine Abstracts

A male, born in 1957, with history of familial spinocerebellar ataxia, Type 2 diabetes (diagnosed in 1999), asthma, learning difficulties, chronic pancreatitis, recurrent falls, multiple low trauma fractures and osteoporosis was referred to Endocrinology Department in 2019. He sustained a right radial fracture at the age of 34 (1992), followed by comminuted right distal radius and Ulna styloid process fracture in 2002, Left and right Neck of Femur fractures in 2013 and 2014 respectively. DEXA scan in 2015 revealed Lumbar spine T score of -3.3 and one third forearm T-score of -4.1. He was started on oral bisphosphonates, calcium and vitamin D supplement. Unfortunately, he was intolerant to oral bisphosphonates. A repeat DEXA scan in 2018 showed a further 3.3% loss of bone density at lumbar spine. He subsequently sustained a left tibial plateau fracture in October 2018 which prompted a Rheumatologist review who suspected Klinefelter”s syndrome and referred to the Endocrinologists. He was on Fluoxetine, Gliclazide and Metformin. On examination his height was 182 cm, BMI 29.7, he had bilateral gynecomastia, sparse axillary and pubic hair, and hypoplastic small testes bilaterally. Laboratory investigations showed Hb125 g/l (normal 130-170), l MCV 90.1 fL (83-101), TSH 0.87 mU/l (0.35-3.50) FT4 11 pmol/l (8-21), negative coeliac screen, adjusted calcium 2.41 mmol/l (2.20-2.60), HbA1c 58 mmol/mol Vitamin D 19 nmol/l (50-120), 9 am testosterone 1.2 nmol/ (normal 6.7-25.6), FSH 38.1 IU/l(normal 1.0-12.0) and LH 15.8 IU/l (normal 0.6-12.1). His karyotype revealed 47 XYY. He is now on testosterone replacement, yearly intravenous Zoledronic acid along with calcium and Vitamin D supplement. 47 XYY, a disorder with extra Y chromosome, which occurs 1 out of 1000 males, is often undiagnosed due to nonspecific clinical features. The chromosomal anomaly is due to nondisjunction in meiosis II. Phenotypically the male could exhibit tall stature, macrocephaly, macroorchidism, hypoplastic scrotum, hypotonia, hyperteliorism, tremors, learning disability, behavioural problems, delayed speech and language development, infertility due to spermatogenesis impairment. Testosterone levels are usually normal, rarely low. Further reading 1. 47,XYY Syndrome: Clinical Phenotype and timing of ascertainment: Martha Z Bardskey et al; J Paediat 2013:163(4):1085-1094. 2. 47,XYY Syndrome and Male Infertility; Ina W. Kim et al: Rev Urol 2013(4): 188-196