Endocrine Abstracts

JOINT4040

Introduction: Turner syndrome (TS) is associated with several phenotypic conditions that increase the likelihood of developing various comorbidities.

Objective: This study aims to assess the prevalence of congenital malformations and the development of age-related comorbid conditions and to compare whether these are different between 45,X monosomy and mosaic karyotypes.

Methods: Retrospective cohort study of patients with TS followed in a referral pediatric center in Portugal from childhood to early adulthood (1977-2024). The karyotype, the prevalence of cardiac and renal congenital malformations, and the prevalence of subsequent specific comorbidities were evaluated, including height and weight status, thyroid disease, menstrual irregularity, developmental delay/learning disabilities and hearing loss.

Results: 69 patients were followed, with a mean age at diagnosis of 5 years (+/- 5.1), and a mean age at first appointment of 8 years (+/-5.2). Of these, 41 (59%) had a 45,X0 karyotype and the remaining had various types of mosaicism. Both congenital heart and renal malformations were more frequent in 45,X0 patients, represented by 41%, (28/69) and 25%, (17/69), respectively. The incidence of subsequent acquired conditions increased with age, more markedly in 45,X monosomy, with the following prevalences: 23% (16/69) thyroiditis, with 63% (10/16) in 45X0, followed by 45X046XX in 19% (3/16); 6% (4/69) overweight/obesity, with 50% (2/4) in 45X046XX; 12% (8/69) menstrual irregularity, with 75% (6/8) in 45X0, followed by 25% (2/8) in 45X046XX; 25% (17/69) developmental delay/learning disabilities, with 59% (10/17) in 45X0, followed by 12% (2/17) in 45X046XX; and 4% (3/69) hearing loss, with 67% (2/3) in 45X0. All patients had short stature, and 75% started GH treatment at a mean age of 9 years and 5 months. Median Turner final height SDS was 0.86(IQR=0.54-1.49) and median SDS for general population was -2.26(IQR=-3.3—1.3). Only two patients achieved target height.

Conclusion: Our findings indicate that Turner syndrome patients with a 45,X0 karyotype exhibit a higher prevalence of both congenital malformations and age-related comorbidities compared to those with mosaic karyotypes. These results highlight the importance of tailored monitoring and early intervention based on karyotype differences to improve clinical outcomes in Turner syndrome.