Gonadal dysgenesis in Turner syndrome with Y-chromosome mosaicism:Two case reports

BACKGROUND Turner syndrome(TS)has a variety of different karyotypes,with a wide range of phenotypic features,but the specific karyotype may not always predict the phenotype.TS with Y chromosome mosaicism may have mixed gonadal dysgenesis,and the mosaicism is related to the potential for gonadoblastoma.CASE SUMMARY In this case report,we report two cases of TS with different karyotypes and gonadal dysgenesis.Patient 1 had obvious virilization,and was positive for the SRY gene,but her karyotype in peripheral blood lymphocytes was 45X.Patient 2 had a mosaic karyotype,45X/46X,dic(Y:Y)(p11.3:p11.2),and the proportion of Y-bearing cells was 50%in peripheral blood lymphocytes,but the patient had normal female external genitalia and streaky gonads,with no genital virilism.Different tissues in the same TS individual may exhibit different ratios of mosaicism.The gonadal determination and differentiation of mosaic TS are primarily dependent on the predominant cell line in the gonads.CONCLUSION In TS patients with virilization,it is necessary to test at least two to three tissues to search for cryptic Y material.

The role of sexual related Y gene detection in the diagnosis of patients with gonadal dysgenesis

Objective To clarify the role of sexual related Y (SRY) gene detection in the diagnosis of gonadal dysgenesis.Methods Sixteen cases of gonadal dysgenesis were included in this study: 5 with androgen insensitivity syndrome, 1 with 17-α-hydroxylase deficiency, 4 with true hermaphrodite, 2 with 45,X/46,XY gonadal dysgenesis, 1 with 45,X gonadal dysgenesis, 1 with XY pure gonadal dysgenesis, 1 with testicular regression, and 1 XY female who gave birth to a normal baby. SRY gene was detected by using polymerase chain reaction (PCR) in blood and gonad samples and by direct sequencing of the SRY motif.Results Among the 16 cases, 15 were blood SRY positive, among which 13 (86.7%) showed the presence of testicular tissue, and 2 showed ovaries without testicular tissue. One SRY negative case showed the presence of testicular tissue. In 3 cases, SRY detection in gonadal tissue correlated with pathological findings but not with blood karyotype. The correlation between peripheral blood SRY and the pathology of the gonads was 81.25% and the correlation between the presence of peripheral blood Y chromosome and pathology of the gonads was 68.75%. Sequencing of the SRY motif in an XY female who gave birth to a normal baby showed no mutation.Conclusions SRY detection is more sensitive and specific than blood karyotype in the prediction of the presence of testicular tissue. Peripheral blood karyotype does not necessarily reflect gonadal type. There may be testicular related factors other than the SRY gene.

A FAMILIAL 46 XY GONADAL DYSGENESIS AND HIGH INCIDENCE OF EMBRYONIC GONADAL TUMORS

The Swyer’s syndrome, 46XY gonadal dysgenesis ( 46XYGD) or XY female, belongs to the category of sexual abnomality. The syndrome is characterized by a female phenotype with streak gonads, 46XY karyotype and complicated by frequent develop of gonadal tumors. A congragated familial 46XYGD was analyzed. We have examined the whole family from many aspects and have followed the affected members more than 10 years. In present case , all eight siblings phenotypically were girls ; the two eldest members died between 1970 1972 from embryonic gonadal tumors. Five of remaining 6 girls were affected by the syndrome of 46 XYGD and two have got the same kind of tumor dysgerminoma. By cytogenetic and cytobiological studies and on the basis of accumulated data the mechanism of gonadal carcinogenesis was analyzed. The origin of dysgerminoma for 46XYGD syndrome was postulated.

Twin dilivery of a 46,XY gonadal dysgenetic woman following vitrified oocytes donation

A 46,XY gonadal dysgenetic woman gave birth to two healthy girls following vitrified oocytes donation. The loss of SRY gene was considered as the cause of this patient. Although similar cases have been reported about pregnancies of 46,XY pure gonadal dysgenetic women, successful delivery from vitrified oocytes has been hardly reported yet. Oocytes vitrification technique provides a beneficial way by saving superfluous oocytes from the pregnancy patients to these women who need.

Management of children with disorders of sex development:20-year experience in southern Thailand

Background:Disorders of sex development(DSD)is a group of sexual differentiation disorders resulting in genital anomalies with defects in gonadal hormone synthesis and/or incomplete genital development.These conditions result in problems concerning the sex assignment of the child.This study aims to describe the clinical features,diagnosis and management of children with DSD in southern Thailand.Methods:The medical records of 117 pediatric patients diagnosed with DSD during the period of 1991-2011 were retrospectively reviewed.Results:Disorders of sex development were categorized into 3 groups:sex chromosome abnormalities(53.0%),46,XX DSD(29.9%)and 46,XY DSD(17.1%).The two most common etiologies of DSD were Turner syndrome(36.8%)and congenital adrenal hyperplasia(29.9%).Ambiguous genitalia/intersex was the main problem in 46,XX DSD(94%)and 46,XY DSD(100%).Sex reassignment was done in 5 children(4.3%)at age of 3-5 years:from male to female in 4 children(1 patient with congenital adrenal hyperplasia,1 patient with 45,X/46,XY DSD,and 2 patients with 46,XX ovotesticular DSD)and from female to male in 1 patient with 46,XX ovotesticular DSD.Of the total 20 children with 46,XY DSD,16(80%)were raised as females.Conclusion:Management of DSD children has many aspects of concern.Sex assignment/reassignment depends on the phenotype(phallus size)of the external genitalia rather than the sex chromosome.

A novel mutation in the SRY gene of a Chinese 46,XY female patient with unilateral mixed germ cell tumor

Objective To determine the nosogenetic factors of a 46,XY female with primary amenorrhea and unilateral mixed germ cell tumor.Methods Eight genes associated with 46,XY gonadal dysgenesis were detected in the patient and her parents by target region captured-next generation sequencing.Results An insertion of a single nucleotide（adenine） at the coding site 230（c.230231insA） located in the high mobility group（HMG） domain of SRY was revealed,which led to a truncated protein（p.Lys77 fsX 27）. This mutation was at position 2655414 of the Y chromosome, supported with 127 unique mapped reads, however, this mutation was not found in the in-house dataset of 1 092 controls. Additionally, none of the candidate gene was detected in the patient’s parents, which indicated that it is a de novo mutation.Conclusion A novel SRY sporadic mutation due to a single nucleotide insertion at position 230（c.230231insA） was identified as the cause of the disease in this patient.Target region captured-next generation sequencing was found to be an effective method for the molecular genetic testing of 46,XY complete gonadal dysgenesis（46,XY CGD）.