Detection of the SRY gene in patients with Turner Syndrome

Y Chromosome Material in Turner Syndrome

Background Turner Syndrome (TS) is a frequently identified chromosomal disease in humans characterized by short stature, sexual infantilism, streak gonads, primary amenorrhea, and a number of somatic anomalies. Approximately 55% of TS individuals have a nonmosaic 45,X karyotype. In addition, a cell line with a Y chromosome is present in 5% of patients, which is undetectable by the standard cytogenetic analysis. The identification of Y chromatin in some TS individuals has been associated with the development of gonadoblastoma. Therefore, it is important to exclude the presence of Y chromatin in TS individuals. In this study, it was planned to detect cases with mosaicism in terms of Y chromatin with the help of Y whole chromosome probes (WCP) from individuals with TS by fluorescence in situ hybridization (FISH) analysis. Methodology Forty-four patients with Turner syndrome, who were being followed up in the Genetics Unit, were contacted and invited for the study. Of the 44 invited patients, 28 responded to the invitation. In this study, it was planned to detect TS patients with mosaicism in terms of Y chromatin with the help of the Y whole chromosome probe. Results The majority of the cases (71.42%) included in the study carried pure X monosomy, which is the classical Turner syndrome karyotype. Other structural X chromosome aberrations, in isolated or mosaic forms, were less frequently represented. Y chromosome sequences were searched in 28 cases with Turner syndrome by the FISH method using Y whole chromosome probe. Y chromosome sequence was detected in one (3.5%) case of 28 cases. Conclusions It is recommended that individuals with Turner syndrome be screened for Y chromatin. Detection of this will provide information and guidance to individuals with Turner syndrome, especially in terms of the risk of developing gonadoblastoma, with advanced clinical consultation. This study was conducted to emphasize the importance of this.

Turner syndrome with positive SRY gene and non-classical congenital adrenal hyperplasia: A case report

BACKGROUND

Co-morbidity of SRY gene turner syndrome (TS) with positive SRY gene and non-classical congenital adrenal hyperplasia (NCAH) is extremely rare and has never been reported to date.

CASE SUMMARY

In this article, we present a 14-year-old girl who was referred to our hospital with short stature (weight of 43 kg and height of 143 cm, < -2 SD) with no secondary sexual characteristics (labia minora dysplasia). Laboratory tests indicated hypergonadotropic hypogonadism with significantly increased androstenedione and 17-hydroxyprogesterone (17-OHP) levels. This was accompanied by the thickening of the extremity of the left adrenal medial limb. The patient’s karyotype was 45,X/46,X, +mar, and cytogenetic analysis using multiplex ligation-dependent probe amplification and high-throughput sequencing indicated that the SRY gene was positive with compound heterozygous mutations in CYP21A2 as the causative gene for congenital adrenal hyperplasia. The sites of the suspected candidate mutations were amplified and verified using Sanger sequencing. The patient was finally diagnosed as having SRY positive TS with NCAH. The patient and her family initially refused medical treatment. At her most recent follow-up visit (age = 15 years old), the patient presented facial hair, height increase to 148 cm, and weight of 52 kg, while androstenedione and 17-OHP levels remained high. The patient was finally willing to take small doses of hydrocortisone (10 mg/d).

CONCLUSION

In conclusion, upon evaluation of the patient mentioned in the report, we feel that 17-OHP measurement and cytogenetic analysis are necessary for TS patients even in the absence of significant virilization signs. This will play a significant role in guiding diagnosis and treatment.

Pubertal induction in girls with Turner Syndrome

Turner Syndrome (TS) is the most common female sex chromosome aneuploidy in females, and patients may present with hypergonadotropic hypogonadism due to gonadal dysgenesis. Timing and modalities of pubertal induction in these patients is still a matter of debate. Aim of this review was to focus on the latest update on pubertal induction in TS. Based on literature data, the following practical approach to this issue is recommended. Pubertal induction should begin between 11 and 12 years of age, starting with low doses of estradiol to preserve height potential. Transdermal 17β-Estradiol (17β-E2) could represent the first-choice induction regimen as it is more physiologic compared to an oral regimen and avoids the first-pass mechanism in the liver. In the case of poor compliance, administration of oral 17β-E2 or ethinyl estradiol could be offered. Incremental dose increases, approximately every 6 months, can contribute to mimic normal pubertal progression until adult dosing is reached over a 2- to 3-year period. Progestin should be added once breakthrough bleeding occurs or after 2 to 3 years of estrogen therapy or if ultrasound shows a mature uterus with thick endometrium. Treatment needs to be individualized and monitored by clinical assessment in relation to patient compliance and satisfaction. Well-designed prospective randomized clinical trials aimed to identify the best estrogen regimen for pubertal induction in TS girls are needed.