Gonadoblastoma in patients with 45,X/46,XY mosaicism: A 16-year experience

Clinical characteristics and surgical treatment of children with 45, X/46, XY differences of sex development

OBJECTIVE

This study retrospectively analyzes the clinical data of 18 children with 45,X/46,XY differences of sex development (DSD), summarizes their clinical features and explores gonadal and Müllerian duct remnants surgical treatment methods.

METHODS

The clinical data of 18 children with karyotype 45,X/46,XY diagnosed in the Department of Urology of Hunan Children's Hospital from March 2011 to October 2021 were collected. All children underwent HCG stimulation testing, laparoscopic exploration, urethroscopy and bilateral gonadal biopsy. After DSD multidisciplinary team (MDT) meeting, some children underwent gonadectomy and genitalia reconstructive surgeries.

RESULTS

The median age at first diagnosis was 1 year and 4 months (range: 10 months ∼ 16 years and 3 months). 5 children presented with female gender; they all maintained their gender assignment. The external masculinisation score (EMS) of patients raised as female was 1 (0∼3) [median (range)]. 13 children presented with male gender, 10 maintained a male gender, 3 were assigned a neutral gender. The EMS of the children raised as male was 5 (2-8) [median (range)], the EMS of the children raised as neutral gender was 4 (3.5-9.5) [median (range)]. The HCG stimulation test was positive in 11 cases, partially positive in 2 case, and negative in 5 cases. There was no relationship between the percentage of chimerism (45X ratio) and the appearance and severity of genital abnormalities. (t=-1.08, P=0.298). There was 1 case of complete gonadal dysgenesis (CGD), 10 cases of mixed gonadal dysgenesis (MGD), 5 cases of partial gonadal dysgenesis (PGD), 1 case of bilateral normal testes and 1 case of ovotesticular DSD (split-lateral type). No gonadal specimen showed germ cell tumor changes. Five cases selected to maintain the female gender, among which 3 cases underwent bilateral gonadectomy and genitalia reconstructive surgeries. Among the 10 children who chose to maintain the male gender, unilateral streak gonadectomy was performed in 4 (57.1%) with MGD, unilateral dysgenetic orchiectomy in 1 (25%) with PGD, and right ovariectomy in 1 with OTDSD. Nine of them underwent genitalia reconstructive surgeries. Four of them preserved their uterus and vagina did not have any complications during the follow-up period.

CONCLUSION

Hypospadias combined with cryptorchidism and residual Müllerian duct structures is the most common phenotype of children with 45, X/46, XY DSD. Mixed gonadal dysgenesis (MGD) is the most common gonadal type. Gender assignment should be carefully selected after a thorough evaluation, while genitalia reconstructive surgery can be considered in selected patients. In children who choose the male gender, the Müllerian duct can be preserved.

Gonadoblastoma in a patient with 45,X/46XY mosaicism

45,X/46,XY mosaicism is a sex development disorder with an estimated incidence of less than 1 in 15,000 live births. Various studies have shown there is an increased risk of germ cell tumours forming in Mosaic Turner syndrome. This includes gonadoblastoma, a clinically benign mixed germ-stromal cell tumour. However, this can later develop into one or several malignant germ cell neoplasms, for which early prophylactic gonadectomy is often recommended in patients with 45,X/46,XY mosaicism. The study presents the case of an 11-year-old patient diagnosed with a Mosaic Turner syndrome karyotype, who underwent prophylactic bilateral gonadectomy.

A Baby With Complete Androgen Insensitivity Syndrome and the Fortuitous Discovery of 45,X/46,XY Mosaicism

Disorders of sex development (DSD) are caused by defects in the complex sexual differentiation cascade, resulting in discordance among an individual's genetic, gonadal, and genital sexes. It affects one in 4,500 live births. A wide spectrum of genital phenotypes can be found depending on the underlying pathogenic mechanism and the developmental stage that is affected. We herein report a newborn with female external genitalia but palpable gonads at labia majora with normal testicular function and structure, which is typical of complete androgen insensitivity syndrome (CAIS). The genetic study revealed 45,X/46,XY mosaicism and c.2081A>C missense androgen receptor gene mutation, indicating the likelihood of co-existing CAIS. This case demonstrated the importance of correlating genital phenotype and the underlying pathogenic mechanism, to provide appropriate management of DSD. Important considerations on managing the gonads about the risks of gonadal malignancies are also discussed.

Deferring gonadectomy in patients with turner syndrome with a genetic Y component is not a safe practice

INTRODUCTION

Patients with Turner syndrome who harbor Y chromosome material are known to be at increased risk of developing germ cell neoplasms. The optimal timing to perform gonadectomy to reduce the risk of cancer development in these patients is not well defined. We present outcomes of Turner with a Y component (TSY) patients who underwent gonadectomy at our institution.

HYPOTHESIS/OBJECTIVE

We hypothesized that tumors could occur in a significant portion of TSY patients at any age and gonadectomy can be safely performed at diagnosis rather than deferred.

STUDY DESIGN

We performed an IRB-approved retrospective single center study in which we queried our institutions electronic health record to identify all patients with TSY who underwent gonadectomy at our institution from 2012 to 2021.

RESULTS

In our series of 18 consecutive TSY patients, a tumor was identified in 6 patients (33.3%): 4 (22.2%) with dysgerminoma (DG) [Fig. 1] and 2 (11.1%) with gonadoblastoma (GB).

DISCUSSION

Our cohort of 18 consecutive TSY who underwent gonadectomy over a 9-year period is the largest published single site cohort to date. Additionally, our patient who was found to have GB at 40 days is to our knowledge the youngest TSY patient to be diagnosed with GB in the literature. This patient's remarkably early incidence of tumor occurrence illustrates the urgency of protective gonadectomy. Given the high incidence of tumor formation in this population and the minimal morbidity associated with gonadectomy, we do not recommend delaying gonadectomy in this population for any reason. Our study is vulnerable to selection bias and confounding innate to any retrospective study. There was variation with respect to the frequency and timing of pre-operative imaging as a strict preoperative imaging protocol with sequential studies was not in place at our institution. Additionally, we do not have a comparison cohort of patients who are being followed without operative intervention as all TSY patients at our institution have undergone gonadectomy.

CONCLUSION

TSY patients cannot be safely observed for tumor formation based on clinical factors such as imaging or age. Gonadectomy is safe with a low complication rate and without tumor recurrence during three-year follow-up. We continue to recommend bilateral gonadectomy in this patient population at the time of diagnosis.

Prevalence and characteristics of gonadoblastoma in a retrospective multi-center study with follow-up investigations of 70 patients with Turner syndrome and a 45,X/46,XY karyotype

INTRODUCTION

A gonadectomy is currently recommended in patients with Turner syndrome (TS) and a 45,X/46,XY karyotype, due to a potential risk of gonadoblastoma (GB). However, the quality of evidence behind this recommendation is low.

OBJECTIVE

This study aimed to evaluate the prevalence of GB, its characteristics, as well as its risk factors, according to the type of Y chromosomal material in the karyotype.

METHODS

Our study within French rare disease centers included patients with TS and a 45,X/46,XY karyotype, without ambiguity of external genitalia. Clinical characteristics of the patients, their age at gonadectomy, and gonadal histology were recorded. The regions of the Y chromosome, the presence of TSPY regions, and the percentage of 45,X/46,XY mosaicism were evaluated.

RESULTS

A total of 70 patients were recruited, with a median age of 29.5 years (21.0-36.0) at the end of follow-up. Fifty-eight patients had a gonadectomy, at a mean age of 15 ± 8 years. GB was present in nine cases. Two were malignant, which were discovered at the age of 14 and 32 years, without metastases. Neither the percentage of XY cells within the 45,X/46,XY mosaicism nor the number of TSPY copies was statistically different in patients with or without GB (P = 0.37). However, the entire Y chromosome was frequent in patients with GB (6/9).

CONCLUSIONS

In our study, including a large number of patients with 45,X/46,XY TS, the prevalence of gonadoblastoma is 12.8%. An entire Y chromosome appears as the main risk factor of GB and should favor early gonadectomy.

SIGNIFICANT STATEMENT

About 10% of patients with TS have a karyotype containing Y chromosomal material: 45,X/46,XY. Its presence is related to the risk of GB. Therefore, a prophylactic gonadectomy is currently recommended in such patients. However, the quality of evidence is low. Our objective was to evaluate the prevalence of GB according to the type of Y-chromosomal material. We found a prevalence of GB of 12.8% in a cohort of 70 TS patients. No sign of hyperandrogenism was observed. The entire Y chromosome was the most frequent type of Y-material in patients with GB. As the prognosis of these tumors was good, a delay of surgery might be discussed.

Sex chromosome DSD individuals with mosaic 45,X0 and aberrant Y chromosomes in 46,XY cells: distinct gender phenotypes and germ cell tumour risks§

"Differences of Sexual Development (DSD)," individuals with rearranged Y chromosome breaks in their 46,XY cells are reported with male and female gender phenotypes and differences in germ cell tumour (GCT) risk. This raised the question of whether male or female gender and GCT risk depends on the site of the break and/or rearrangement of the individual´s Y chromosome. In this paper, we report molecular mapping of the breakpoint on the aberrant Y chromosome of 22 DSD individuals with a 45,X/46,XY karyotype reared with a different gender. Their Y chromosome breaks are found at different sites on the long and short Y arms. Our data indicate that gender rearing is, neither dependent on the site of Y breakage, nor on the amount of 45,X0 cells in the individuals' leukocytes. Most prominent are secondary rearrangements of the Y chromosome breaks forming di-centric Y-structures ("dic-Y"). Duplications of the short Y arm and the proximal part of the long Y arm are the results. A putative GCT risk has been analysed with immunohistochemical experiments on some dysgenetic gonadal tissue sections. With specific antibodies for OCT3/4 expression, we marked the pluripotent germ cell fraction being potential tumour precursor cells. With specific antibodies for DDX3Y, TSPY, and UTY we analyzed their putative Gonadoblastoma Y (GBY) tumour susceptibility function in the same specimen. We conclude GBY expression is only diagnostic for GCT development in the aberrant germ cells of these DSD individuals when strong OCT3/4 expression has marked their pluripotency.

Gonadal tumor risk in pediatric and adolescent phenotypic females with disorders of sex development and Y chromosomal constitution with different genetic etiologies

OBJECTIVES

This retrospective study sought to investigate the risk and proportion of gonadal neoplasms in phenotypic female pediatric patients with DSD and the presence of the Y chromosome and different genetic backgrounds in a single Chinese center.

MATERIALS AND METHODS

From January 2012 to December 2020, pediatric and adolescent patients with DSD and the presence of the Y chromosome who had unambiguous female genitalia and underwent bilateral gonadectomy or gonadal biopsy were included in this study. Patients' demographics, karyotype, laboratory test results, gross pathology, and histology of gonadal tissue were all collected. The patients were divided into three groups based on their different genetic backgrounds, and the percentage of gonadal tumors was calculated to assess the risk of gonadal tumor and malignancy by etiology.

RESULTS

A total of 22 patients with DSD and an unambiguous female phenotype with a Y chromosome were recruited. The mean age was 10.91 ± 4.99 years (9 months to 19 years). Gonadal neoplasia was confirmed in six (27.3%) cases by pathological examination of surgical gonadal tissue samples. Among 44 gonadal samples from these 22 patients, the following were identified: five gonadoblastomas, three dysgerminomas, and two Leydig cell tumors. The youngest patient with a tumor was a 2-year-old girl with 46,XY complete gonadal dysgenesis (46,XY CGD or Swyer syndrome) and bilateral gonadoblastoma. Patients with 46,XY complete gonadal dysgenesis (4/6; 66.7%) had the highest tumor occurrence rate. Among 10 patients with Turner syndrome with the presence of the Y chromosome, only one patient was diagnosed with a gonadal tumor. Leydig cell tumor was diagnosed in only one of six patients with 46,XY androgen synthesis/action disorders.

CONCLUSION

Pediatric patients with 46,XY complete gonadal dysgenesis had a significantly increased risk of developing gonadal tumors and underwent prophylactic gonadectomy as soon as the diagnosis was confirmed, whereas those with Turner syndrome with Y chromosome and 46,XY androgen synthesis/action disorders had a relatively low risk. In view of the limited number of patients, a large multicenter study with close follow-ups is needed to support these conclusions.

Normal and Premature Adrenarche

Adrenarche is the maturational increase in adrenal androgen production that normally begins in early childhood. It results from changes in the secretory response to adrenocorticotropin (ACTH) that are best indexed by dehydroepiandrosterone sulfate (DHEAS) rise. These changes are related to the development of the zona reticularis (ZR) and its unique gene/enzyme expression pattern of low 3ß-hydroxysteroid dehydrogenase type 2 with high cytochrome b5A, sulfotransferase 2A1, and 17ß-hydroxysteroid dehydrogenase type 5. Recently 11-ketotestosterone was identified as an important bioactive adrenarchal androgen. Birth weight, body growth, obesity, and prolactin are related to ZR development. Adrenarchal androgens normally contribute to the onset of sexual pubic hair (pubarche) and sebaceous and apocrine gland development. Premature adrenarche causes ≥90% of premature pubarche (PP). Its cause is unknown. Affected children have a significantly increased growth rate with proportionate bone age advancement that typically does not compromise growth potential. Serum DHEAS and testosterone levels increase to levels normal for early female puberty. It is associated with mildly increased risks for obesity, insulin resistance, and possibly mood disorder and polycystic ovary syndrome. Between 5% and 10% of PP is due to virilizing disorders, which are usually characterized by more rapid advancement of pubarche and compromise of adult height potential than premature adrenarche. Most cases are due to nonclassic congenital adrenal hyperplasia. Algorithms are presented for the differential diagnosis of PP. This review highlights recent advances in molecular genetic and developmental biologic understanding of ZR development and insights into adrenarche emanating from mass spectrometric steroid assays.

Post-operative complications following masculinizing genitoplasty in moderate to severe genital atypia: results from a multicenter, observational prospective cohort study

INTRODUCTION

Differences of sex development (DSD) are congenital conditions in which there is atypical chromosomal, gonadal and/or phenotypic sex. A phenotype of severe genital atypia in patients raised as male is a relatively rare occurrence and standards for management are lacking. Decision making for early surgical planning in these rare cases includes, but is not limited to, degree of atypia, location of testes, and presence of Mϋllerian remnants. In this study we describe surgical approaches and short-term outcomes for masculinizing genitoplasty in moderate to severe genital atypia in young patients raised male, for whom parents opted for early surgery.

METHODS

This NIH-sponsored study is an ongoing, observational, multicenter investigation assessing medical, surgical and psychological outcomes in children and their parents affected by atypical genitalia due to DSD. Participants were prospectively enrolled from 12 children's hospitals across the United States that specialize in DSD care. Criteria for child enrollment were a Quigley score of 3-6 in those with a 46, XY or 45,X/46, XY chromosome complement, age <3 years with no previous genitoplasty; patients were included independent of whether genitoplasty was performed. Cosmesis was graded according to a 4-point Likert scale and complications per the Clavian-Dindo classification.

RESULTS

Of the 31 participants, 30 underwent hypospadias repair and 1 patient did not undergo a genitoplasty procedure. The majority of participants (22) received a staged hypospadias repair. Seventeen complications were identified in 12 of the 31 children (41%) at 12 months of follow up. Glans dehiscence and urethrocutaneous fistula were the most common complications. Orchiopexy was performed in 14 (44%) and streak gonads were removed in 4 (13%) participants. Both parents and surgeons reported improved cosmesis after surgery when compared to baseline.

CONCLUSION

Genitoplasty was chosen by parents for the majority of children eligible for study. No single surgical approach for masculinizing moderate to severe genital ambiguity in young patients with 46, XY or 45,X/46, XY DSD was adopted by all surgeons. Complications occurred in 41% of those who underwent genitoplasty for severe hypospadias. Overall, appearance of the genitals, as determined by parents and surgeons, improved following genitoplasty. Outcomes of early genitoplasty are needed to guide families when making decisions about such procedures for their young children.

Imaging Findings of Septooptic Dysplasia and Joubert's Syndrome in A Patient with Mixed Gonadal Dysgenesis: A New Coexistence?

Ambiguous genitalia is a common feature in most disorders of sexual development. These disorders can be evaluated within three groups: sex chromosome disorders, 46,XY disorders, and 46,XX disorders. Except for Turner's syndrome, these anomalies are not related to neurological developmental anomalies. A 6-month-old patient presenting with ambiguous genitalia had developmental and motor retardation with nystagmus. In karyotype analysis, 45,X/46,XY sequences were found, compatible with mixed gonadal dysgenesis (GD). Laboratory findings were normal except for low serum total testosterone level. The uterus and left adnexal structures were seen in imaging. There were no gonads in the labial/scrotal regions. Septooptic dysplasia (SOD) and Joubert's syndrome (JS) were detected in cranial magnetic resonance imaging. This presentation reports rare association of SOD and JS in a child with mixed GD.

Clinical phenotype and management of individuals with mosaic monosomy X with Y chromosome material stratified by genital phenotype

Individuals mosaic for monosomy X and a cell line with Y chromosome material can have genitalia that appear phenotypical female, male, or ambiguous. Those with this karyotype and typical female genitalia are diagnosed with Turner syndrome; however, this definition specifically excludes those with genitalia other than typical female. There is limited information on whether medical and neurodevelopmental risks are similar among individuals with monosomy X and Y chromosome material across genital phenotypes. This multicenter retrospective study compared comorbidities and clinical management in individuals with monosomy X and Y material and male/ambiguous genitalia to those with typical female genitalia. Electronic medical records for all patients with monosomy X and Y material (n = 76) at two large U.S. pediatric centers were abstracted for predetermined data and outcomes. Logistic regression was used to compare the two phenotypic groups adjusting for site and duration of follow-up. The male/ambiguous genitalia group was just as likely to have congenital heart disease (RR 1.0, 95%CI [0.5-1.9]), autoimmune disease (RR 0.6 [0.2-1.3]), and neurodevelopmental disorders (RR 1.4 [0.8-1.2]) as those with female genitalia. Despite similar risks, they were less likely to receive screening and counseling. In conclusion, individuals with monosomy X and Y chromosome material have similar medical and neurodevelopmental risks relative to individuals with Turner syndrome regardless of genitalia, but there are notable differences in clinical management.

Imaging in pediatric ovarian tumors

The spectrum of ovarian tumors in the pediatric population differs significantly from that in adults. Germ cell tumors are the predominant class of ovarian tumors in children, whereas epithelial tumors are the most common in adults. Ultrasonography is the modality of choice for the initial evaluation of pediatric ovarian tumors. Determining the diagnosis based on imaging may prove difficult, and combining the imaging findings with the clinical scenario is very helpful in reaching a differential diagnosis during clinical practice. We will discuss the spectrum of ovarian neoplasms in the pediatric population and describe their clinical, pathologic, and imaging characteristics. A few unique entities related to ovarian tumors, such as growing teratoma syndrome, anti-N-methyl-D-aspartate receptor encephalitis, and hereditary ovarian tumor syndromes, are also discussed. In addition, we will review several entities that may mimic ovarian neoplasms as well as their distinct imaging features.

Variation of Gonadal Dysgenesis and Tumor Risk in Patients With 45,X/46,XY Mosaicism

OBJECTIVE

To describe the gonadal features of patients with 45,X/46,XY mosaicism, and to evaluate the prevalence of gonadal tumor in different phenotypes.

MATERIALS AND METHODS

The medical records of consecutive patients with 45,X/46,XY karyotype or its variants who had undergone gonadal biopsy or gonadectomy at a single institute between 1996 and 2017 were retrospectively reviewed.

RESULTS

Of 34 patients with 45,X/46,XY mosaicism, a unilateral dysgenetic testis and a contralateral streak gonad was detected in 20 patients (59%), bilateral streak gonads in 9 (26%), and bilateral dysgenetic testes in 5 (15%). A gonad composed of both streak and dysgenetic testicular portions was observed in 7 gonads of 6 patients. All streak gonads were removed, and bilateral gonadectomy was performed in 15 patients raised as girls. Pathologic examination revealed gonadal tumors in 6 of the 34 (18%) patients, including a gonadoblastoma in 7 gonads among 5 patients and an association of dysgerminoma with gonadoblastoma in 1 gonad. All 6 patients who developed gonadal tumor had female genitalia. Postoperative course was uneventful except 1 boy. A seminoma was developed in his soritaly scrotal testis at the age of 16 years.

CONCLUSION

The prevalence of gonadal tumor in patients with 45,X/46,XY mosaicism may vary according to the phenotype, and high in patients with female phenotype. Considering the increased risk of gonadal tumors in such patients, early investigation and individual management, including prophylactic gonadectomy, are recommended. In male patients, a close follow-up of the preserved testes is mandatory until adulthood.

Dysgerminoma in a 10-Year Old with 45X/46XY Turner Syndrome Mosaicism

BACKGROUND

Turner syndrome is a genetic disorder resulting from the absence of or structural abnormality of one X chromosome. The presence of Y chromosome material in girls with Turner syndrome confers an increased risk of benign and malignant germ cell tumor and prophylactic bilateral gonadectomy is recommended.

CASE

A 10-year-old Turner mosaic syndrome (45X/46XY) patient underwent prophylactic gonadectomy after unremarkable preoperative pelvic imaging. Histopathology showed a streak right gonad, and left gonad with gonadoblastoma with limited degree of infiltrating germinoma.

SUMMARYAND CONCLUSION

Gonadoblastoma and dysgerminoma have been reported in girls with Turner mosaic who carry Y chromosome material. Prophylactic gonadectomy should be considered in these girls without delay.

Usefulness of imprint cytology of gonadoblastoma with dysgerminoma in a patient with Turner syndrome and a Y chromosome: A case report and literature review

Ovarian gonadoblastoma coexisting with a dysgerminoma is extremely rare in patients with Turner syndrome (TS) and a Y chromosome. The cytological findings, including imprint cytology, of these unusual ovarian tumors have rarely been reported. We report a rare patient with a gonadoblastoma with dysgerminoma, 3.0 × 2.0 cm in size; she was a 19-year-old woman with TS and a Y chromosome. She underwent laparoscopic bilateral gonadectomy, and the tumor was classified as stage IA (pT1aNxM0) according to the International Federation of Gynecology and Obstetrics classification system. Intraoperative imprint cytology revealed two types of neoplastic cells: small tumor cells surrounding light green-stained or eosinophilic hyaline globules with marked calcification, suspicious for gonadoblastoma; and large, round, atypical cells with abundant cytoplasm, macronucleoli, and marked lymphocytic infiltration (two-cell pattern), suspicious for dysgerminoma. The cytology results in our patient may represent the second reported results of imprint cytology describing a gonadoblastoma with dysgerminoma. They are the first reported results in a patient with TS and a Y chromosome.

Early Bilateral Gonadoblastoma Associated With 45,X/46,XY Mosaicism: The Spectrum of Undifferentiated Gonadal Tissue and Gonadoblastoma in the First Months of Life

45,X/46,XY mosaicism is one of a heterogenous group of congenital conditions known as differences (disorders) of sex development (DSD) that results in abnormal development of internal and external genitalia. Patients with DSD, particularly those with segments of the Y chromosome, are at increased risk for germ cell tumors including gonadoblastoma. Gonadoblastoma is a neoplasm comprised of a mixture of germ cells and elements resembling immature granulosa or Sertoli cells with or without Leydig cells or lutein-type cells in an ovarian type stroma. Gonadoblastoma has an increased prevalence of 15% to 40% in patients with 45,X/46,XY mosaicism and has been previously reported in patients as young as 5 months of age with that karyotype. Herein, we describe a 3-month-old child with 45,X/46,XY karyotype who was referred for the evaluation of asymmetric labia majora. Additional evaluation revealed left streak gonad and right dysplastic/dysgenetic testis. Both gonads contained foci of cells typical for gonadoblastoma as well as undifferentiated gonadal tissue, underscoring the potential for very early infantile gonadoblastoma and the spectrum of developmental anomalies associated with this karyotype.

The Dilemma of Sex of Rearing: A Case of a 45,X/46,XY Neonate with Hydrocolpos

BACKGROUND

A rare disorder of sex development is 45,X/46,XY mosaicism, which is phenotypically very heterogenous, ranging from normal male (or female) to that of genital ambiguity of varying degrees.

CASE

We report a case of a neonate with 45,X/46,XY mosaicism and hydrocolpos, and we point out the dilemma and the difficulty in gender assignment.

SUMMARY AND CONCLUSION

Gender assignment of cases with frank genital ambiguity is often difficult to be determined, because several factors have to be taken into consideration, such as genital appearance, anticipated urological and sexual function, capacity for future fertility, gonadal malignancy risk, and psychosocial factors. A multidisciplinary approach is definitely needed in the management of such cases.

Discordant sex between fetal screening and postnatal phenotype requires evaluation

OBJECTIVE

Non-invasive prenatal screening (NIPS) utilizes circulating cell-free DNA (cfDNA) to screen for fetal genetic abnormalities. NIPS is the first widely-available prenatal screen to assess genotypic sex. Most pediatricians have limited familiarity with NIPS technology and potential etiologies of discordant results. Increased familiarity may provide diagnostic insight and improve clinical care.

STUDY DESIGN

We reviewed all patients with discordant genotypic fetal sex assessed by cfDNA and neonatal phenotypic sex referred to our medical center.

RESULT

Four infants with discordant cfDNA result and phenotypic sex were identified. Etiologies include vanishing twin syndrome, difference of sexual development, sex chromosome aneuploidy and maternal chimerism.

CONCLUSIONS

We present four cases illustrating potential etiologies of discordant cfDNA result and postnatal phenotypic sex. Unanticipated cfDNA results offer the perinatologist a unique opportunity for early diagnosis and targeted treatment of various conditions, many of which may not have otherwise been detected in the perinatal period.

The Evaluation of Cases with Y-Chromosome Gonadal Dysgenesis: Clinical Experience over 18 Years

OBJECTIVE

Y-chromosome gonadal dysgenesis (GD) is a rare subgroup of disorders of sexual development (DSD) which results from underdeveloped testis and may exhibit heterogenous symptoms. These patients are phenotypically classified into two groups - complete and partial, and their karyotypic description is either 46,XY GD or 45,X/46,XY GD. In this study; we aimed to evaluate the characteristics of cases with Y-chromosome GD.

METHODS

Thirty eight cases were followed-up between 1998 and 2016. The age of admission ranged between 0 and 17 years. Clinical and laboratory findings as well as follow-up characteristics of the cases were evaluated retrospectively from the patient files.

RESULTS

There were 26 cases (four complete, 22 partial) in the 46,XY GD group, and 12 cases (four complete, 8 patients with complete GD in the 45,X/46,XY. Mean age at admission was 6.2±4.6 years for all cases. Patients with complete GD in the 45,X/46,XY GD group were diagnosed earlier that the patients with complete GD in the 46,XY group [11 years vs. 14.31 years of age (p<0.01)]. There were no additional findings in 55% of all patients. In the remaining 45% additional clinical findings, mainly short stature, were detected in 75% of the patients in the 45,X/46,XY GD and 30% of the patients in the 46,XY GD groups. All patients with complete 46,XY and 45,X/46,XY GD were raised as females. There was no gender dysphoria in patients that were raised as females, except for one case. Gonadectomy was performed in 14 patients, at a mean age of 8.75±2.3 years and pathological assessment of the gonads was reported as normal in all cases.

CONCLUSION

Y-chromosome GD is a very heterogenous clinical and genetic disorder and requires a multifaceted approach to management. Whether including syndromic features or not, associated clinical features may lead to earlier diagnosis, especially in complete forms of GD. Due to difficulties encountered in the long-term follow-up of these patients, evaluation of appropriateness of sex of rearing decision is not truly possible. Performance of gonadectomy during the first decade appears be a preventive factor for tumor development since these tumors are usually seen during the second decade.

Early Bilateral Gonadoblastoma in a Young Child with Mosaicism for Turner Syndrome and Trisomy 18 with Y Chromosome

Mosaic Turner syndrome (TSM) commonly occurs in the form of 45,X/46,XX and 45,X/46,X,i(X)(q10). Mosaicism for a Y chromosome, 45,X/46,XY, has been well documented and is associated with increased risk of gonadoblastoma (GB). To date, there are only six reported cases of TSM with a trisomy 18 karyotype, and only two of these were phenotypically female with 45,X/47,XY,+18 karyotype. We present the case of a phenotypically female infant born with dysmorphic features. G-banded karyotype and interphase FISH of blood showed 45,X in 95% and 47,XY,+18 (trisomy 18) in 5% of cells analysed. However, interphase FISH of buccal cells showed only the presence of the 45,X cell line. Due to the presence of Y chromosome material, elective gonadectomy was performed at 13 months of age. There were bilateral streak ovaries with early evidence of GB bilaterally, a rudimentary uterus and bilateral fallopian tubes with unilateral ectopic adrenal tissue identified histologically. Interphase FISH of the gonadal tissue was similar to the blood findings with 45,X in 86% of cells and 47,XY,+18 in 14% of cells analysed. This case highlights a rare karyotype of TSM and trisomy 18 in the same patient and is the first reporting the associated finding of bilateral GB.

Adolescent Female With Turner's Syndrome and 46,X,der(Y) del(Y)(p11.2)del(q11.2) Karyotype With Gonadoblastoma and Dysgerminoma

Gonadal dysgenesis patients with Y chromosomal material are subject to increased risk for germ cell tumors. We report a case of an adolescent female presenting with Turner-like syndrome with primary amenorrhea and Tanner stage 1 breast development. Karyotype showed one X chromosome and a minute pericentromeric fragment of Y chromosome without any functional Y genes in all the cells, unlike a mosaic pattern, represented as 46,X,der(Y)del(Y)(p11.2)del(q11.2). Laparoscopic bilateral gonadectomy was performed due to presence of Y chromosome material and histopathology confirmed gonadoblastoma with a focus of dysgerminoma of the right ovary. A robotic-assisted surgical staging for dysgerminoma was performed which was confirmed to be negative for malignancy. This points at the putative genes for gonadoblastoma to be present around the centromere of the Y chromosome.

A practical guide for evaluating gonadal germ cell tumor predisposition in differences of sex development

Differences of Sex Development (DSD) includes a wide spectrum of etiologies and phenotypes. A subset of individuals with DSDs are predisposed to gonadal germ cell tumor (GCT). In this setting, GCT risk varies widely, depending on the DSD molecular etiology and penetrance. Prognostication based on molecular diagnosis remains challenging, as natural history data specific to recently identified molecular causes of DSD is lacking. In this review, we provide a framework for the clinical geneticist to consider GCT tumor risk in the patient with DSD. We discuss germ cell development and etiology of GCT growth, along with parameters to consider when recommending prophylactic gonadectomy including fertility, hormonal output, and malignant GTC treatment outcomes. Shortly after the 2006 reorganization of DSD nomenclature, literature reviews of natural history publications stratified GCT risk by a chromosomal, pathological, and hormonal taxonomy. Our 2017 literature review reveals a larger body of publications. However, the broad DSD GCT risk stratification within the 2006 taxonomy remains stable. We discuss precise GCT risk assessment for specific diagnoses, including androgen insensitivity, Smith-Lemli-Opitz, and 46,XY with MAP3K1 mutations and gonadal dysgenesis, as examples. We also examine the GCT risk in non-DSD syndromes, in addition to the cancer risks in DSD patients with dimorphic gonads and genitalia. This review is intended to provide a nuanced assessment of relative germ cell tumor risk in the DSD patient, including modern precise molecular diagnosis, for use by the clinical geneticist.