Detailed tests reveal disorder of sex development

XY chromosomes found despite female external genitalia

Not directly related to this article. [Image generated by AI]
Not directly related to this article. [Image generated by AI]

A Japanese woman who visited a hospital after her period had not started by high school was found to have two testes inside her body. Further testing led to a diagnosis of a disorder of sex development, a condition in which sexual differentiation differs from typical male or female patterns.

According to WithNews, a media outlet affiliated with Japan's Asahi Shimbun, the woman — identified only as A — was born in Japan's northern Kanto region in 1981. When she was a first-year high school student, she visited a hospital after her period had not begun and learned for the first time that her sex chromosomes were XY and that she had two testes inside her body.

A had been aware since childhood of a ball-like protrusion near her external genitalia. She recalled thinking "something is different," and her parents were also aware of it, but she had no other health problems and never sought medical attention. She was raised as a girl and did not know the reason behind her physical characteristics until she reached high school.

After entering high school with her period still absent, A visited three gynecology clinics, but none found a clear cause. She eventually underwent detailed testing at the urology department of a regional national university hospital, where she learned facts she had not anticipated.

The tests confirmed her sex chromosomes as 46,XY. MRI scans and other imaging revealed that the protrusions near her external genitalia were testes — one was externally visible, while another was located inside her body.

Doctors diagnosed A with a disorder of sex development.

The condition is an umbrella term for congenital states in which chromosomal, gonadal and external genital development follow divergent patterns. It encompasses several subtypes depending on the underlying cause and physical characteristics.

One form of the disorder is androgen insensitivity syndrome, or AIS, in which a person with XY chromosomes does not respond normally to androgens, the male sex hormones. In complete AIS, or CAIS, the external genitalia are female and breast development occurs at puberty, but the absence of a uterus means menstruation never begins and pregnancy is not possible.

Because testes remaining inside the body carry a risk of developing tumors, A underwent surgery to have them removed at age 25.

She currently takes female hormones daily and undergoes blood tests every six months to maintain her health.

Narumi Satoshi, a pediatrics professor at Keio University Hospital, said of disorders of sex development that "roughly one in 5,000 people has symptoms severe enough to make it difficult to determine sex at birth."

However, those with milder symptoms may go through life without ever knowing the full details of their physical condition.

A similar case emerged in China last month, when a 26-year-old woman discovered during a routine health checkup that she had no uterus or ovaries. Chromosome testing confirmed a 46,XY karyotype, and she was also diagnosed with complete AIS.

A 2016 study by Swedish researchers published in the Journal of Clinical Endocrinology & Metabolism found the prevalence of 46,XY women to be an average of 3.5 per 100,000 female births. AIS was found in an average of 2.3 per 100,000.


jshan@heraldcorp.com