ESPE Abstracts

Introduction: Disorders of sexual development (DSD) encompass a complex group of conditions characterized by a discrepancy between phenotypic and chromosomal sex, sometimes associated with impaired sex steroid synthesis or hormone action. DSD can be detected prenatally; however, establishing their etiology remains challenging. Our objective is to identify steroid profiles that could guide prenatal molecular analyses for diagnosis and perinatal care.

Methods: We analyzed the levels of 10 steroids (testosterone, delta4-androstenedione (D4), dehydroepiandrosterone, 17-hydroxyprogesterone, 11-deoxycortisol, 21-deoxycortisol, deoxycorticosterone, pregnenolone, 17-hydroxypregnenolone, cortisol) by liquid chromatography tandem mass spectrometry (LC-MSMS) (1290-6495c Agilent®) in amniotic fluid (AF) from 46,XY fetuses collected between 01/01/2014 and 01/03/2024 (n = 422). Fetal clinical and molecular data (obtained by targeted sequencing or NGS panel) were collected when available. Statistical analyses were performed using R software (v4.3.3).

Results: Molecular analyses identified a pathogenic variant in a DSD-related gene in 35 cases: 7 cases of hormone resistance due to androgen receptor gene defect (AR), 17 cases of testicular development gene abnormality (D), 6 cases of HSD17B3 gene defect (HSD17B3), and 5 cases of SRD5A2 gene defect (SRD5A2). For each of these 4 groups, steroid concentrations were compared to a control group of AF samples from 46,XY fetuses without morphological or chromosomal abnormalities collected between 01/01/12 and 31/08/14. Testosterone concentration was significantly reduced in D and HSD17B3 (P <0.001, P = 0.001, all the p-values were obtained after the Wilcoxon test and corrected with the Holm method.), and appeared increased in AR and SRD5A2 (P = 0.064, P = 0.057, p-values close to significance threshold) compared to controls. D4 concentration was significantly increased in AR (P = 0.022) and reduced in D (P = 0.002). Only HSD17B3 had a significantly higher ratio of testosterone to D4 (T/D4 ratio, P <0.001). We also observed a combined effect of testosterone and D4 levels (sum of D4+T) within the mutated groups AR (increased compared to controls, P = 0.025) and the D group (decreased compared to controls, P <0.001).

Conclusion: Our findings suggest that specific patterns of D4 and testosterone levels, along with the T/D4 ratio and the combined effect of both hormones, can be used as indicators of DSD caused by certain genetic abnormalities. Identifying steroid profiles specific to pathophysiological mechanisms offers a promising approach for early diagnosis and management of 46XY DSD especially for patients with unexplained DSD by guiding specific genetic testing.