Cytogenetic spectrum and clinical presentation of Klinefelter syndrome: A comprehensive study from South India

Abstract

BackgroundKlinefelter syndrome (KS) is a common sex chromosome abnormality that mostly presents as testicular failure and a myriad of other clinical features. The phenotypic features and their severity vary between individuals, age groups and cytogenetic subtypes. Karyotyping remains the method of choice for the diagnosis of KS despite advanced molecular testing in this modern era. The objective of this study was to determine the cytogenetic subtypes, clinical presentation and hormonal profile of patients with KS. MethodsRetrospective observational study comprised patients with KS determined by cytogenetic analysis at the tertiary care centre in south India from 2001 to 2019. Clinical details including testicular size, hormone levels and semen analysis were obtained from the medical records. ResultsThere were 147 KS (145 post-natal and 2 pre-natal) patients ranging in age from two days to 51 years, 116 (74.8%) patients being ≥18 years. Classic (cKS), mosaic (mKS) and variant KS (vKS) accounted for 126 (85.7%), 9 (6.1%) and 12 (8.2%) cases and their mean ages were 26.6, 29.6 and 12.8 years, respectively. cKS and mKS had diverse clinical presentations including several co-morbidities of which small testes were most common (94.8%). vKS presented with behavioural problems (58.3%) without any comorbidities. Testosterone (p < 0.05), FSH and LH levels were abnormal in >90% of patients. ConclusionAll three cytogenetic subtypes of KS were seen in our patients. cKS was seen in all ages, mKS was common in adults and vKS was seen predominantly in children. Early diagnosis of KS and timely medical intervention may alter the clinical outcomes and improve the quality of life.