Turner syndrome (TS) is the most common genetic disease associated with the X-chromosome abnormality. Sex chromosome monosomy (45,X) occurs in 4050% of the cases. 5% of patients with TS, in addition to cells lacking the genetic material of the X-chromosome, have a cell line with Y-chromosome, whether complete or not, which can be clinically manifested by virilization and mixed gonadal dysgenesis. Early identification of the Y-chromosome genetic material in patients with TS is of great clinical importance because of the increased risk of germ cell tumors, especially if growth hormone is used.
Case report: A 6 year-old girls was consulted to endocrinology department for decrease in the growth velocity from the age of two years and clitoromegalia. Considering the presence of clinical features of TS, short stature (height 102.5 cm (−2 SDS), parental height 171.0 cm (+2 SDS)), small size of the uterus and ovaries according to ultrasound, clitoromegalia, hirsutism girl was carried out molecular cytogenetic FISH study. Cytogenetic study revealed besides a cell line with 45,X a second cell line where the short arm of the Y-chromosome was translocated onto the short arm of a chromosome 7, karyotype: 45,×, add(7)(p21).ish(SRY+)/45,×.ish(SRY−). Diagnostic laparoscopy with gonadectomy was performed. Histological examination of the left gonad revealed a stroma of the ovary without follicles and a tissue of the rudimentary testicle, the right gonad - fragments of the ovarian stroma without follicles. Growth hormone treatment was initiated at the age of 6.5 years, due to significant growth retardation. At the age of 15 years 9 months treatment with somatropin was canceled because of little growth potential (height velocity 2.6 cm/year, bone age > 14 years). The achieved height was 154.5 cm (−2 SDS). Estrogen replacement was started at the age of 11.5 years (estradiol valerat 0.5 mg/day). The dose of estrogens increased gradually, and was 1 mg/day, which allowed to reach the Tanner 3 stage of sexual development 1.5 years after the onset of estrogen therapy. It is planned to administer cyclic therapy with the addition of progesterone to prevent endometrial cancer associated with prolonged estrogen monotherapy.
Conclusion: Molecular techniques such as FISH or PCR for identifying Y-chromosome-specific sequences are recommended to be used in patients with TS and signs of virilization and/or when there is a marker chromosome not identified by classical cytogenetics.
27 - 29 Sep 2018
European Society for Paediatric Endocrinology