Proportion and Pattern of Chromosomal Abnormalities in Primary Amenorrhea in Kerala- A Retrospective Study

Abstract

Introduction: Primary amenorrhoea may be due to chromosomal abnormalities and identification of these abnormalities is important for counselling and management of these individuals. Aim: To identify the prevalence of chromosomal abnormalities in a cohort of primary amenorrhoea patients and to evaluate the various pattern of chromosomal abnormalities. Materials and Methods: This retrospective study was conducted at Government Medical College, Thiruvananthapuram, Kerala, India (serves as a referral centre for most of south Kerala and adjoining districts of Tamil Nadu), from January 2013 to December 2020. All phenotypically females, in the age group of 15-30 years, attending the Genetic Clinic with a diagnosis of primary amenorrhoea were evaluated with karyotype from peripheral blood as per the standard protocol. An abstraction proforma was used to collect the data from the master case sheet available in the genetic laboratory. Cytogenetic abnormalities were described as per the standard International System for Human Cytogenomic Nomenclature (ISCN). For statistical analysis, proportion of cases with chromosome abnormality in the cohort was described as percentage. Results: Chromosomal analysis revealed 25.5% (38 out of 149) with abnormal karyotype. Among the abnormalities, the most common abnormality was 45, X (12, 31.6%) Turners syndrome. Other abnormalities included sex reversal female (46, XY) in six (15.8%), isochromosome Turner syndrome in five (13.1%), partial deletion in X chromosome in three (7.8%) and various combination of mosaic pattern in nine (23.7%) cases. Hypergonadotropic hypogonadism was significantly associated with chromosomal abnormality. Conclusion: Cytogenetic abnormality is a cause for primary amenorrhoea in a significant proportion of cases and karyotype should be an integral part of evaluation in such cases. In resource limited settings, karyotype is having more clinical utility in cases with hypergonadotropic hypogonadism.

Keywords

• isochromosome
• karyotype
• mosaicism
• sex reversal
• turner syndrome