ESPE Abstracts

Introduction: The external masculinisation score (EMS) has been utilised as an objective numerical description of the external genitalia in undermasculinised patients with DSD in several studies. However, data on longitudinal change in EMS in the routine clinical setting are lacking.

Objectives: To determine the longitudinal change in EMS and its determinants in a cohort of boys with XY DSD in one specialist centre.

Methods: Boys with XY DSD between 2010 and 2020 were included. Clinical information on initial (EMS1) and most recent EMS (EMS2), results of endocrine and genetic investigations, as well as genital surgery and testosterone therapy were obtained from medical records.

Results: 205 boys with median age at initial and last assessment of 0.8 yrs (range, 0.0, 18) and 4.9 yrs (0.4, 19.3), respectively (P<0.0001), were identified. Median follow-up time was 3.4 yrs (0.2, 17.3). Median EMS, out of 12, at first and last assessment was 8 (2, 12) and 11 (1.5, 12), respectively (P<0.0001). Surgery was performed in 170 (83%) boys whereas testosterone therapy was recorded in 11 (5%). Boys with combined genital anomalies were more likely to show an increase in EMS but less likely to achieve an EMS2 of 12 whereas those with undescended testes were more likely to achieve the EMS2 of 12 but also had greater chance to have EMS2 decreased due to orchidectomy. Of the 40 boys who had endocrine abnormality and a gene variant (n, 20) or not (n, 20), the median change (Δ) in EMS was 1.5 (0, 9) and 0.5 (-2, 4.5), respectively (P=0.045). ΔEMS, duration of follow-up and the number of surgical procedures did not differ between those with normal endocrine investigations and with or without a gene variant. Testosterone therapy was not associated with an increase in EMS whereas those who had surgery showed a significant increase in EMS.

Conclusions: The EMS in boys with XY DSD improves over childhood and adolescence. The change in EMS in boys with DSD is poorer in those who have a combination of both endocrine and genetic abnormality and also in those who are hypogonadal and require testosterone therapy.