A Rare Cause of Male Infertility: 45,X/46,XY Mosaicism

Genetic causes and management of male infertility

Infertility affects approximately 15% of couples. With infertility such a common problem in a generally healthy age group, complete evaluation is needed of both men and women. Infertility work up for men includes a semen analysis, the results of which suggest various supplemental studies, including karyotype. Karyotype is indicated when a patient has findings on history or physical exam concerning for chromosomal abnormalities, azoospermia, or severe oligospermia (count <5 million/mL). The most common chromosomal numerical abnormality found on karyotype is Klinefelter syndrome which is classified as redundant sex chromosomes, with the most common chromosomal arrangement being 47, XXY. If a patient is found to have a chromosomal abnormality such as Klinefelter’s, there is still a chance of fertility using testicular sperm extraction and in-vitro fertilization.

Sertoli cell-only syndrome: etiology and clinical management

Almost 50% of infertility cases are due to male factors, and spermatogenesis failure is one of the most severe forms of male infertility. Sertoli cell-only syndrome (SCOS) also known as germ cell aplasia is characterized by azoospermia in which the seminiferous tubules of testicular biopsy are lined only with Sertoli cells. The definitive diagnosis of SCOS is by diagnostic testicular biopsy. Although SCOS may be a result of Klinefelter syndrome, most of the SCOS men have a normal karyotype. Along with genetic aberrations, signaling pathways and endocrine processes might be major factors in the development of SCOS. Sperm retrieval and intracytoplasmic sperm injection (ICSI) are available treatments for SCOS. However, some SCOS patients do not have therapeutic options to help them having a biological child. This review aims to summarize our present knowledge about SCOS and to highlight the importance of future researches in the diagnosis and treatment of this disorder.

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.

Multidisciplinary Approach to the Child with Sex Chromosomal Mosaicism Including a Y-Containing Cell Line

Children born with sex chromosomal mosaicism including material derived from the Y chromosome may present with a broad phenotypical spectrum. Both boys and girls can present with Turner features and functional health problems typically associated with Turner syndrome, but the presence of Y-chromosomal material can modify some aspects of the condition. We retrospectively analyzed the results of our cohort of 21 individuals (14 boys, 7 girls) with sex chromosomal mosaicism including Y-derived material followed at Ghent University Hospital according to our local multidisciplinary Turner surveillance protocol. Results were compared with literature data, focusing on similarities and differences between girls and boys with this condition. Age at diagnosis was lower in boys compared to girls but the difference was not significant. Short stature is a key feature of the condition both in girls and boys, but skeletal maturation may be different between groups. The effects of growth-hormone therapy remain unclear. Cardiac (33%), ear-nose- throat (ENT) (77.8%) and renal (28.6%) problems were as prevalent in boys as in girls from our cohort, and did not differ from literature data. In line with literature reports, a significant difference in the presence of premalignant germ cell tumors between males (0%) and females (42.9%) was found (p = 0.026). Taken together, this study demonstrates the similarities between girls with Turner syndrome and children with sex chromosomal mosaicism including Y-derived material, regardless of the child’s gender. Nowadays, girls with Turner syndrome are offered a dedicated multidisciplinary follow-up in many centers. We advocate a similar follow-up program for all children who have sex chromosomal mosaicism that includes Y-derived material, with special attention to growth, cardiac and ear-nose-throat problems, gonadal function and malignancies.

SRY-negative 45,X/46,XY adult male with complete masculinization and infertility: A case report and review of literature

BACKGROUND

45,X/46,XY mosaicism is a rare chromosomal abnormality with a wide range of phenotypes in both males and females, from normal individuals with different degrees of genital ambiguity to those who show signs of Turner’s syndrome. More rarely, cases of 45,X/46,XY mosaicism with a normal-appearing male phenotype are not found until a chromosome test is performed to investigate the cause of male infertility.

CASE SUMMARY

In this study, a 29-year-old male patient with complete azoospermia is reported. Chromosomal analyses of his lymphocytes revealed the karyotype 45,X[93%]/46,X,+mar(Y)[7%]. In addition, Y chromosome-specific markers, such as SRY, ZFY, AZFa, AZFb and AZFc, were not observed in his blood DNA according to multiplex polymerase chain reaction test. A literature review identified several 45,X/46,XY cases with a normal-appearing male phenotype, most of whom were diagnosed during infertility investigation. However, the present case is the first SRY-negative 45,X/46,XY male case diagnosed during a premarital medical examination.

CONCLUSION

This finding further suggests that sex determination is a complex process regulated by multiple genetic and environmental factors.

Successful surgical sperm retrieval from a patient with 45,X/46,XY mosaicism followed by in vitro fertilization pregnancy: A case report

RATIONALE

Mixed gonadal dysgenesis is a rare disorder of sex development, and typically contains a mosaic 45,X/46,XY karyotype.

PATIENT CONCERNS

We reported here a case of a 42-year-old man with infertility for 6 years and inability to ejaculate during intercourse.

DIAGNOSIS

Physical examination confirmed that the external genitalia was male. The right testis of this patient was resected and the left testis had intrascrotal calcification. Hormone test showed that the level of follicle-stimulating hormone was 20.14 IU/L (normal range, 1.27-19.26 IU/L). No deletion or mutation was found on the sex-determining region Y. H&E staining revealed seminiferous tubule dysgenesis. The karyotyping in peripheral blood and testicular tissue was 45,X/46,XY and 45,X/47,XYY/46,XY, respectively. Based on these results, the patient was diagnosed with 45,X/46,XY or 45,X/47,XYY/46,XY mosaicism and gonadal dysgenesis.

INTERVENTIONS

In vitro fertilization and embryo transfer technology were used to help his wife to achieve pregnancy.

OUTCOMES

A normal baby boy was born at 36 weeks of gestation with a karyotype 46, XY.

LESSONS

We reported a rare case of a karyotype 45,X/46,XY in blood cells and 45,X/47, XYY/46,XY in testicular tissue. In vitro fertilization and embryo transfer technology can help to achieve pregnancy.

45,X/46,XY Mosaicism and Normozoospermia in a Patient with Male Phenotype

The phenotypic spectrum of 45,X/46,XY mosaic males varies greatly. Previous reports have only described cases with either oligozoospermia, growth retardation, or elevated gonadotropins. However, the present case presented with normozoospermia, and normal height, sperm DNA fragmentation index (DFI), and gonadotropins. The male and his spouse were referred to The Fertility Clinic, Skive Regional Hospital, due to 2 years of infertility. After failure of several attempts of assisted reproductive treatment (ART), the male underwent genetic analysis. Conventional karyotyping in peripheral lymphocytes yielded a low-grade 45,X/46,XY mosaicism, confirmed by fluorescence in situ hybridization (FISH) showing 6% 45,X cells. A FISH test performed on interphase nuclei from buccal mucosal cells yielded one cell with only one X-signal (0.6%), explaining the normal phenotype of the patient, but not the infertility. FISH test for sperm aneuploidy showed normal range parameters, except for a 10-fold elevated gonosomal nullisomy rate (2.1%). Hence, germinal mosaicism may be an explanation of the infertility of the case. Increased sex nullisomy levels may reflect an aberrant testicular environment compromising fertility even though sperm euploidy rates and other sperm parameters do not preclude a successful treatment with ART. Based on these results, the couple decided to use donor semen for their subsequent intrauterine insemination treatment and obtained a successful pregnancy.