7119 Klinefelter Syndrome in a Tertiary Referral Clinic: A Case Series and Clinical Audit
Authors: Luo Jinghang , Sarlos Stella , Giri Rinky , Sim Ie-Wen , McLachlan Robert Ian , Allan Carolyn A , Upreti Rita 
Published: October 2024

Abstract
Disclosure: J. Luo: None. S. Sarlos: None. R. Giri: None. I. Sim: None. R.I. McLachlan: None. C.A. Allan: None. R. Upreti: None.
Background: Klinefelter syndrome, the most common chromosomal disorder in men, remains underdiagnosed in many of those affected. Klinefelter syndrome is associated with hypogonadism and infertility, as well as an increased risk for venous thromboembolism (VTE), cardiometabolic disease, osteoporosis and gynaecomastia in adults. We studied the clinical features and disease associations in a tertiary referral cohort, and audited the care provided. Methods: Following ethics approval, adult patients with Klinefelter syndrome attending a Clinical Andrology Service in a tertiary Australian institution since 1 January 2011 were recruited. A database was established and demographics, aspects of initial diagnosis, ongoing treatments and comorbidities were documented. We audited our care using the European Academy of Andrology 2021 Guidelines for Klinefelter Syndrome. Results: Of 94 patients eligible, 57 patients consented to participation. The median age of diagnosis was 28 years, with the most common karyotype being 47,XXY (74%), followed by mosaic (20%) and higher degree polysomy (6%). Infertility (44%) and hypogonadism (33%) were the most common reasons for diagnosis. Most patients (88%) were treated with testosterone. Five men (11%) had genetic children with seven (18%) having previously attempted surgical sperm extraction. VTE occurred in seven patients (12%), with five on long-term anticoagulation following VTE diagnosis. Cardiovascular risk factor prevalence assessed at a median age of 42 years included increased BMI (72%), hypertension (25%), dyslipidaemia (70%), tobacco use (26%), impaired fasting glucose (11%) and type 2 diabetes (22%), though only one patient had a previous cardiovascular event. Osteopenia and osteoporosis were present in 28% and 4% of patients respectively, though only two patients had minimal trauma fractures. The audit of longitudinal care showed that gynaecomastia status was underreported (42%) in our clinic, whilst assessment and management of other health domains were mostly in keeping with the current recommendations. Conclusions: Klinefelter syndrome diagnosis continues to be delayed until adulthood in many men, with presentations most commonly involving infertility and/or hypogonadism. Our tertiary cohort demonstrates low rates of fertility treatment and success, which is likely multifactorial. There is a high burden of VTE, cardiovascular risk factors and reduced bone density despite testosterone treatment. Low rates of cardiovascular events and fracture may be reflective of a younger cohort as well as more aggressive risk factor management in a sub-specialist service. Gynaecomastia identification, documentation and management are areas for potential improvement. Increased awareness of Klinefelter syndrome and research into its associated risks are essential for standardising care and improving long-term outcomes.
Presentation: 6/1/2024