Complete or Partial Gonadal Dysgenesis

View a glossary of key terms and definitions commonly used in discussions about sex development. 

What is Complete or Partial Gonadal Dysgenesis?

Gonadal dysgenesis refers to conditions in which the gonads (ovaries or testes) are underdeveloped, affecting hormone production and the development of internal and external genitalia. There are two main types:

Complete Gonadal Dysgenesis

In this condition, the gonads, called “streak” gonads, do not produce estrogen or testosterone before birth. This usually results in female-typical external genitalia.

Partial Gonadal Dysgenesis

Here, the gonads partially form into testicles but produce less sex hormone than typical testicles before birth. This usually leads to atypical or nonbinary external genitalia.

What Causes Complete or Partial Gonadal Dysgenesis?

Gonadal dysgenesis is caused by differences in developmental signals before birth. While some specific genetic causes are known, which can be inherited or occur spontaneously, the exact reasons can vary from person to person.

How is Complete or Partial Gonadal Dysgenesis Diagnosed?

Complete Gonadal Dysgenesis

• Individuals with female external genitalia may be found to have 46,XY chromosomes through prenatal genetic testing or later in life.
• A girl may not start puberty, showing no signs of breast development or menstrual periods. Hormone tests measuring LH, FSH, estradiol, and anti-Müllerian hormone will indicate non-functioning gonads.
• A pelvic ultrasound will typically show very small gonads or none at all.

Partial Gonadal Dysgenesis

• The external genitalia are atypical or nonbinary in appearance.
• Hormone levels of LH, FSH, testosterone, and anti-Müllerian hormone suggest partial function of the testicles.
• A pelvic ultrasound may reveal partially developed testicles that are located higher in the pelvis or abdomen.

How is Complete or Partial Gonadal Dysgenesis Treated?

Treatment for gonadal dysgenesis includes:

• Psychological support: To help individuals and families cope with the condition.
• Hormone supplementation: Estrogen or testosterone may be provided at puberty to support development.
• Gonadal management discussions: Since the gonads may have an increased risk of developing tumors, they are sometimes removed.
• Surgery on external genitalia: This is rarely urgent and may be considered based on individual needs and preferences.