Here, for the first time, the structure of genes involved in sex determination in mammals (full Sry and partial Rspo1, Eif2s3x, and Eif2s3y) was analyzed for the European mole Talpa europaea with ovotestes in females. We confirmed male-specificity for Eif2s3y and Sry. Five exons were revealed for Rspo1 and the deep similarity with the structure of this gene in T. occidentalis was proved. The most intriguing result was obtained for the Sry gene, which, in placental mammals, initiates male development. We described two exons for this canonically single-exon gene: the first (initial) exon is only 15 bp while the second exon includes 450 bp. The exons are divided by an extended intron of about 1894 bp, including the fragment of the LINE retroposon. Moreover, in chromatogram fragments, which correspond to intron and DNA areas, flanking both exons, we revealed double peaks, similar to heterozygous nucleotide sites of autosomal genes. This may indicate the existence of two or more copies of the Sry gene. Proof of copies requires an additional in-depth study. We hypothesize that unusual structure and possible supernumerary copies of Sry may be involved in ovotestes formation.

True hermaphroditism is a disorder of sex development (DSD), accounting for less than 5% of all DSD cases, defined by the simultaneous presence of testicular tissue and ovarian tissue in the same individual. In the reported case, the patient presented two genetic mutations involved in the pathogenic pathway of the DSD condition associated with the clinical features of Kallmann syndrome (KS), a developmental disease that associates hypogonadotropic hypogonadism (HH), due to gonadotropin-releasing hormone deficiency, and anosmia, related to the absence or hypoplasia of the olfactory bulbs. Given the variable degree of hyposmia in KS, the distinction between KS and normosmic idiopathic HH is currently unclear, especially as HH patients do not always undergo detailed olfactory testing. This syndrome is very rare, with an estimated prevalence of 1:80,000 in males and 1:40,000 in females. This is the only case report concerning a patient with 46 XX true hermaphroditism affected by HH and digenic inheritance of Kallmann syndrome.

The term \'differences of sex development\' (DSD) refers to a group of congenital conditions that are associated with atypical development of chromosomal, gonadal, and/or anatomical sex. DSD in individuals with a 46,XX karyotype can occur due to fetal or postnatal exposure to elevated amount of androgens or maldevelopment of internal genitalia. Clinical phenotype could be quite variable and for this reason these conditions could be diagnosed at birth, in newborns with atypical genitalia, but also even later in life, due to progressive virilization during adolescence, or pubertal delay. Understand the physiological development and the molecular bases of gonadal and adrenal structures is crucial to determine the diagnosis and best management and treatment for these patients. The most common cause of DSD in 46,XX newborns is congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency, determining primary adrenal insufficiency and androgen excess. In this review we will focus on the other rare causes of 46,XX DSD, outside CAH, summarizing the most relevant data on genetic, clinical aspects, puberty and fertility outcomes of these rare diseases.

Ovotesticular disorder of sex development (OT-DSD) is a rare condition characterized by the presence of both ovarian and testicular tissue in the gonads. Management and sex designation of these patients depend on several factors, and an underlying potential for gender dysphoria should be acknowledged. We present a case of a patient diagnosed with 46,XX OT-DSD at 12 months old who was attributed a female sex designation but started manifesting gender dysphoria during adolescence. Gender identity is an important factor to consider on long-term follow-up of OT-DSD patients.

Ovotestis is a rare cause of sexual ambiguity characterized by the presence in a patient of both testicular and ovarian tissue, leading to the development of both male and female structures. We report a case of ovotestis diagnosed in an adolescent, with a review of the literature.
A 15-year-old patient presented with a right scrotal swelling associated with gynecomastia. Histology showed a juxtaposition of ovarian stroma with ovarian follicle and seminiferous tubules. Karyotype revealed a male subject (XY). We have therefore retained the diagnosis of ovotesticular disorders of sex development.
Ovotestis is a rare finding, heterogeneous in its genetic etiology and clinical presentation. While many patients are diagnosed during infancy or childhood, we presented a case diagnosed in a 15-year-old adolescent.

A case is reported herein of a true hermaphrodite (TH) with an ovotestis, a uterus, a vagina, and an underdeveloped phallus. The patient was raised by his parents as a male, based on the presence of a phallus with ambiguous genitalia. He started experiencing breast enlargement at the age of 14 and menarche by the age of 17. He was reviewed using ultrasound, magnetic resonance imaging of the abdomen, and karyotyping, and the reports showed evidence of Mullerian structures and 46 XX karyotyping. Based on the preferences of the patient and his parents and their psychological outlook toward the male gender, a total mastectomy, hysterectomy, bilateral gonadectomy, and total vaginectomy were performed. This was followed by reconstruction of the male genitalia and supplemented with male hormone replacement therapy. Accordingly, a TH was assigned a male gender.

Sea urchins are usually gonochoristic, with all of their five gonads either testes or ovaries. Here, we report an unusual case of hermaphroditism in the purple sea urchin, Strongylocentrotus purpuratus. The hermaphrodite is self-fertile, and one of the gonads is an ovotestis; it is largely an ovary with a small segment containing fully mature sperm. Molecular analysis demonstrated that each gonad producedviable gametes, and we identified for the first time a somatic sex-specific marker in this phylum: Doublesex and mab-3 related transcription factor 1 (DMRT1). This finding also enabled us to analyze the somatic tissues of the hermaphrodite, and we found that the oral tissues (including gut) were out of register with the aboral tissues (including tube feet) enabling a genetic lineage analysis. Results from this study support a genetic basis of sex determination in sea urchins, the viability of hermaphroditism, and distinguish gonad determination from somatic tissue organization in the adult.

Unlike gonochoristic fishes, sex is fixed after gonadal differentiation (primary sex determination), and sex can be altered in adults (secondary sex determination) of hermaphroditic fish species. The secondary sex determination of hermaphroditic fish has focused on the differences between testicular tissue and ovarian tissue during the sex change process. However, comprehensive studies analyzing ovarian tissue or testicular tissue independently have not been performed. Hermaphroditic black porgy shows a digonic gonad (ovarian tissue with testicular tissue separated by connective tissue). Protandrous black porgy has stable maleness during the first two reproductive cycles (<2 years old), and approximately 50% enter femaleness (natural sex change) during the third reproductive cycle. Precocious femaleness is rarely observed in the estradiol-17β (E2)-induced female phase (oocytes maintained at the primary oocyte stage), and a reversible female-to-male sex change is found after E2 is withdrawn in <2-year-old fish. However, precocious femaleness (oocytes entering the vitellogenic oocyte stage) is observed in testis-removed fish in <2-year-old fish. We used this characteristic to study secondary sex determination (femaleness) in ovarian tissue via transcriptomic analysis. Cell proliferation analysis showed that BrdU (5-bromo-2\'-deoxyuridine)-incorporated germline cells were significantly increased in the testis-removed fish (female) compared to the control (sham) fish (male) during the nonspawning season (2 months after surgery). qPCR analysis showed that there were no differences in pituitary-releasing hormones (lhb and gtha) in pituitary and ovarian steroidogenesis-related factors (star, cyp11a1, hsd3b1, and cyp19a1a) or female-related genes (wnt4a, bmp15, gdf9, figla, and foxl2) in ovarian tissues between intact and testis-removed fish (2 months after surgery). Low expression of pituitary fshb and ovarian cyp17a1 was found after 2 months of surgery. However, we did find small numbers of genes (289 genes) showing sexual fate dimorphic expression in both groups by transcriptomic analysis (1 month after surgery). The expression profiles of these differentially expressed genes were further examined by qPCR. Our present work identified several candidate genes in ovarian tissue that may be involved in the early period of secondary sex determination (femaleness) in black porgy. The data confirmed our previous suggestion that testicular tissue plays an important role in secondary sex determination in protandrous black porgy.

Mixed gonadal dysgenesis (MGD) is a rare disorder of sexual development. Also known as 45XO/46XY mosaicism, MGD is characterized by highly variable sexual phenotypes and an increased risk of gonadal malignancy. Patients with MGD often have a unilateral descended gonad and contralaterally either a streak gonad or no gonad. We present the case of a patient with a dysgenetic, nonpalpable gonad with imaging features of an ovotestis. These imaging features are generally more indicative of ovotesticular disorder of sexual development (previously true hermaphrodite), which is a condition with low risk of gonadal malignancy. Further evaluation with histology and genetic analysis confirmed the diagnosis of MGD. It is important to diagnose MGD to allow for early operative intervention and screening for malignancy.

Disorders of sex development (DSD) are a group of congenital conditions associated with anomalous development of internal and external genital organs. Ovotesticular disorder of sex development (OT-DSD) is a condition in which a child is born with both testicular tissue (that possesses variable fertility potential within seminiferous tubules) and ovarian tissue (with primordial follicles). These tissues may be co-existent in the same gonad (ovotestis) or independently in separate gonads. Here, we report the clinical case of a 21-month-old boy that we met during a humanitarian surgical mission performed at Hospital Dr. Francisco Moscoso Puello, Santo Domingo, Dominican Republic. The child was referred for management of hypospadias, cryptorchidism, and symptomatic right inguinal and umbilical hernias. With further chromosomal evaluation, the diagnosis of SRY-negative OT-DSD was made, and shared decision-making was used to determine the timing of gender assignment, reconstruction, and the child\'s long-term care team. OT-DSD is an uncommon condition with unclear causes. Once a DSD condition is suspected at birth, a complete investigation should be performed, encompassing a descriptive examination, a basic electrolyte and hormonal profile, genetic assessment, and pelvic ultrasound. Consultation with a multidisciplinary team is warranted, including pediatric urology or pediatric surgery with urologic training, endocrinology, genetics, psychology, pathology, and the patient\'s pediatrician at minimum before surgical reconstruction. It is crucial to involve the patient and their family with shared decision-making before surgery or gender assignment.