What are Differences of Sex Development (DSD)?
Differences of sex development (DSD) describes a group of conditions that occur early in pregnancy in which sex development is not typical. Some people may use different words to describe this, such as intersex, or use the name of the actual condition.
There are two main factors that decide whether a baby develops as male or female: genetic factors and sex hormones. The reproductive body parts may develop differently if there is a change in any of the factors needed for sex development. This results in DSD.
Background
Both “sex” and “gender” are related to being a boy or a girl. “Sex” is about a person’s body parts and how their body grows and develops. A person’s sex is due to a mix of genetic factors and sex hormones. A person’s gender is about their sense of self.
Genetic Factors
Chromosomes are large groups of genes. You can think about genes as instruction codes that are packaged in a person’s chromosomes. There are some genes that are involved in sex development.
Most people have 46 chromosomes. Two of the chromosomes, the X and the Y, are called sex chromosomes. Most boys have one X and one Y chromosome. Most girls have two X chromosomes. However, some boys and girls may have different chromosome patterns. For example, some girls have one X and one Y chromosome.
Changes in some genes or chromosome patterns may explain why some people’s bodies develop differently.
Sex Hormones
Hormones are chemical messages that a person’s body makes. They tell the body how to grow and develop. Sex hormones make a person’s body parts develop in a male or female way, before birth and at puberty.
Sex hormones are made by glands inside the body called gonads. There are two types of gonads: testes and ovaries. Most boys have testes and most girls have ovaries. Genetic factors (for example, if a Y chromosome is present or not) are important for sex glands to develop into testes or ovaries.
Testes make hormones called androgens. Testosterone is one type of androgen. Ovaries make estrogen, and some testosterone. In addition, testes make sperm and ovaries make eggs.
Reproductive Body Parts
People have reproductive parts inside and outside their bodies. Gonads are one of the parts inside the body. Also inside the body, most girls have a vagina, a cervix and a uterus. The parts outside the body are called genitals. Most boys have a penis and a scrotum. Most girls have a clitoris, labia and a hole for the vagina.
Some people with DSD may have a mix of male and female reproductive parts or genitals that are not clearly male or female.
What causes differences of sex development?
There are many types of DSD. The reasons for people to be born with one of these conditions may be a change that involves any of the following:
- Sex chromosomes or genes
- Sex glands (such as testes or ovaries)
- Sex hormones
When are differences of sex development suspected?
DSD affects people throughout the lifespan. While some conditions are discovered at birth, others may be found later, during childhood, puberty or even adulthood. DSD can affect both the genitals on the outside and the reproductive body parts on the inside of the body.
Some people with DSD have other health issues, while many people with DSD are healthy.
Some examples of when DSD may be suspected:
- The way a newborn baby’s genitals look can make it hard to tell if the baby is a boy or a girl
- Genitals do not look typical such as:
- May be hard to tell if the baby is a boy or a girl
- Enlarged clitoris
- Very small penis
- Hypospadias (hole for urination at the base, instead of the tip, of the penis in a boy)
- Absent testes in a boy
- Sex chromosomes do not match how the genitals look (can find this out before birth or later in life)
- Child does not go through puberty or menstruation does not start
- Infertility in adulthood
How are differences of sex development diagnosed?
The doctors may order tests, such as:
- Karyotype: This is a blood test that looks at all of the body’s chromosomes, including the X and Y chromosomes.
- Genetic testing: This is a blood test to look for changes in the genes that are known to cause DSD.
- Hormone testing: This is a blood test that checks what hormones the gonads are making and how much.
- Pelvic ultrasound: This is an imaging test that looks for the gonads and for a uterus.
- Laparoscopy: This is a surgery using a small camera. The surgeon looks for the reproductive parts inside the body. The surgeon may also take small pieces of tissue.
How do we care for people with differences of sex development?
The DSD team at Cincinnati Children’s includes doctors, nurses, psychologists, genetic counselors, child life specialists and social workers from six specialties:
Our team works together to provide care for all ages, from counseling before birth to treatment into adulthood.
Treatment depends on the specific condition and the issues involved. Treatment and services may include:
- Diagnostic evaluation, which includes:
- Physical exam
- Blood tests
- Imaging (X-ray, ultrasound, MRI)
- Psychosocial support
- Genetic counseling
- Medical treatment
- Hormone therapy
- Procedures (as needed)
- Vaginal dilation
- Diagnostic procedures
- Surgery
