# Ovotesticular syndrome

Ovotesticular syndrome (also known as ovotesticular disorder or OT-DSD) is a rare congenital condition where an individual is born with both ovarian and testicular tissue. It is one of the rarest disorders of sex development (DSDs), with only 500 reported cases. Commonly, one or both gonads is an ovotestis containing both types of tissue. Although it is similar in some ways to mixed gonadal dysgenesis, the conditions can be distinguished histologically.

## Terminology

In the past, ovotesticular syndrome was referred to as true hermaphroditism, which is considered outdated as of 2006. The term "true hermaphroditism" was considered very misleading by many medical organizations and by many advocacy groups, as hermaphroditism refers to a species that produces both sperm and ova, something that is impossible in humans.

## Symptoms
### Physical

* Enlargement of one or both breasts in men (gynecomastia) (present in 75% of cases)
* Small phallus midway in size between a clitoris and a penis
* Incompletely closed urogenital opening (shallow vagina)
* Abnormal urethra opening on the perineum

### Cognitive

Studies on the limited amount of cases on ovotesticular syndrome shows the condition does not cause cognitive impairment.

## Causes

There are several ways in which this may occur.
* It can be caused by the division of one ovum, followed by fertilization of each haploid ovum and fusion of the two zygotes early in development
* Single gene mutations.
* Alternately, an ovum can be fertilized by two sperm followed by trisomic rescue in one or more daughter cells.
* Two ova fertilized by two sperm cells will occasionally fuse to form a tetragametic chimera, if one male zygote and one female zygote fuse.
* It can be associated with a mutation in the SRY gene.
* Etc.
** Mitotic or meiotic errors: Can cause sex chromosome mosaicism
** Double fertilization: Can result in 46XX/46XY chimerism, which occurs when an X sperm and a Y sperm fertilize an ovum
** Fusion of two ova: Can result in 46XX/46XY chimerism, which occurs when one male zygote and one female zygote fuse
** Mutation in the SRY gene: Can be associated with ovotesticular syndrome
** Mutation of downstream autosomal genes: Can explain SRY-negative ovotesticular syndrome
** Mutation/duplication or deletion of an X-linked locus: Can explain SRY-negative ovotesticular syndrome
** Depression of autosomal testis-determining genes: Can explain 46,XX true hermaphroditism
* Only 3 reports exist attributing specific cases of the condition to some form of duplication of the SOX9 gene; making this an incredibly rare cause.
Note: The SRY gene has a 8 to 10% of showing up in those that are found to have ovotesticular syndrome. Due to the genetic makeup of an SRY gene, it implies that ovotesticular syndrome is more of a heterogeneous condition.

## Variations

It is documented to show up in 4 different variations. Those being Bilateral, Unilateral, Lateral, and Indeterminate.
* Bilateral - both the ovaries and testicle tissues appear on both sides.
* Unilateral - on one side there is what is known as ovotestis (both ovary and testicle tissue), and the other side has either ovary tissue or testicular tissue - not both.
* Lateral - both testicular and ovary tissue are present, but are on opposite sides.
* Indeterminate - it is known that the condition is present, but it isn't evident as to where the testicular or ovary tissue is located.

### Karyotypes

In ovotesticular syndrome, XX is the most common (55-80% of cases); most individuals with this form are SRY negative.
Next most common are XX/XY (20-30% of cases) and XY (5-15% of cases), with the remainder being a variety of other chromosomal anomalies and mosaicisms.
Some degree of mosaicism is present in about 25%. Encountered karyotypes include 46XX/46XY, or 46XX/47XXY or XX & XY with SRY mutations, mixed chromosomal anomalies or hormone deficiency/excess disorders, 47XXY. Less than 1% have XX/XY chimerism.

## Prevalence

Ovotesticular syndrome represents 5% of all sex disorder differentiations.
The exact number of confirmed cases is uncertain, but by 1991 approximately 500 cases had been confirmed.
It has also been estimated that more than 525 have been documented. While it can appear anywhere in the world, and be reported or unreported, the greatest amounts reported of ovotesticular syndrome is from Africa and Europe.

## Fertility

The gonad most likely to function is the ovary. The ovotestes show evidence of ovulation in 50% of cases. Spermatogenesis has only been observed in solitary testes and not in the testicular portions of ovotestes. According to a 1994 study, spermatogenesis has only been proven in two cases. In one of the two cases, a phenotypically male individual with XX,46/XY,46 mixture had fathered a child. It has been estimated that 80% of cases could be fertile as females with surgery.

### Documented cases of fertility

There are extremely rare cases of fertility in humans with ovotesticular syndrome.
In 1994, a study on 283 cases found 21 pregnancies from 10 individuals with ovotesticular syndrome, while one allegedly fathered a child.
As of 2010, there have been at least 11 reported cases of fertility in humans with ovotesticular syndrome in the scientific literature, with one case of a person with XY-predominant (96%) mosaic giving birth. All known offspring have been male. There has been at least one case of an individual being fertile as a male.
There is a hypothetical scenario, in which it could be possible for a human to self-fertilize. If a human chimera is formed from a male and female zygote fusing into a single embryo, giving an individual functional gonadal tissue of both types, such self-fertilization is feasible. Indeed, it is known to occur in non-human species where hermaphroditic animals are common and has been observed in a rabbit. However, no such case of functional self-fertilization or "true bi-sexuality" has been documented in humans.

## Society and culture

Having ovotesticular syndrome of sexual development can make one inadmissible for service in the United States Armed Forces.

### M.C. v. Aaronson

The U.S. legal case of M.C. v. Aaronson, advanced by intersex civil society organization interACT with the Southern Poverty Law Center, was brought before the courts in 2013. The child in the case was born in December 2004 with ovotestes, initially determined as male, but subsequently assigned female and placed in the care of South Carolina Department of Social Services in February 2005. Physicians responsible for M.C. initially concluded that surgery was not urgent or necessary and M.C. had potential to identify as male or female, but, in April 2006, M.C. was subjected to feminizing medical interventions. According to the Encyclopedia Britannica, "The reconstruction of female genitalia was more readily performed than the reconstruction of male genitalia, so ambiguous individuals often were made to be female." He was adopted in December 2006. M.C. identified as male at the time the case was brought, at age eight. The defendant in the case, Dr. Ian Aaronson, had written in 2001 that "feminizing genitoplasty on an infant who might eventually identify herself as a boy would be catastrophic".
The defendants sought to dismiss the case and seek a defense of qualified immunity, but these were denied by the District Court for the District of South Carolina. In January 2015, the Court of Appeals for the Fourth Circuit reversed this decision and dismissed the complaint, stating that, it did not "mean to diminish the severe harm that M.C. claims to have suffered" but that in 2006 it was not clear that there was precedent that the surgery on a sixteen-month-old violated an established constitutional right. The Court did not rule on whether or not the surgery violated M.C.'s constitutional rights.
State suits were subsequently filed. In July 2017, it was reported that the case had been settled out of court by the Medical University of South Carolina for $440,000. The university denied negligence, but agreed to a "compromise" settlement to avoid "costs of litigation."