Despite having female hormones, a 27-year-old woman in China discovered that she has a male sex chromosome - and a testicle in her abdomen.

The rare genetic condition, known as congenital adrenal hyperplasia (HSRC), is a disease characterized by the deficiency of an enzyme necessary for the adrenal glands - located at the top of the kidneys - to produce certain hormones. Instead, the glands can overproduce androgens, or male hormones such as testosterone.

It affects around 1 in 50,000 newborns and can result in gender characteristics that don't align with typical definitions.

The woman, referred to as Li Yuan for privacy reasons, had her first symptoms at the age of 18, such as the absence of menstruation and delayed breast development.

Initial medical examinations suggested potential ovarian failure and abnormal hormone levels. Although further chromosomal tests were recommended, Li did not take them seriously at the time. The South China Morning Post reports that Li's parents are both carriers of recessive genes that increase the likelihood of inheriting this disease - Li had a 25% chance of inheriting it.

Years later, shortly before her wedding, Li underwent further medical tests which led to her shocking diagnosis. Duan Jie, a gynecologist with years of experience, confirmed that although Li appears to be female and socially identifies as such, she is genetically male.

"Socially, she is female. But chromosomally, she is male," explains the veteran.

In more severe cases of HSRC, carriers may have ambiguous genitalia at birth and suffer from dehydration and vomiting problems.

Pre-marital test reveals China bride-to-be has testicle in stomach
A young Chinese woman who was planning her wedding had a thorough medical check-up because she was not menstruating, and found out that she was biologically a man.
South China Morning PostIris Jiang

Often, people with milder manifestations of the disease are not diagnosed until symptoms appear during adolescence or adulthood, such as precocious puberty or fertility problems.

In Li's case - and to further complicate his health - he was diagnosed with osteoporosis and vitamin D deficiency, probably aggravated by the lack of early treatment.

The presence of the testicle posed a high risk of developing cancer, which is why it had to be surgically removed as a matter of urgency. The operation took place at the beginning of April and Li has since been forced to undergo long-term hormone therapy to control the disease.