What are the types of disorders of sex differentiation (DSD)?

What are the types of disorders of sex differentiation (DSD)?

There are different types of DSD and each type has a different cause. The most common DSD types in children include:

• Female with ambiguous or male genitals (46, XX DSD): A child with this type of DSD has the female chromosomes (XX) with normal ovaries and womb. Genitals may be male or ambiguous (not having a clear sex). The child may have an enlarged clitoris (a female sex organ) that looks like a penis. The lower section of the vagina may be closed. The most common cause of this DSD is a condition called congenital adrenal hyperplasia (CAH). A child with CAH does not have a specific enzyme that the body needs to make the hormones cortisol and aldosterone. Without these two hormones, the body produces more androgens (male sex hormones). If the affected child is female, the high androgen levels before birth cause the genitals to become more male in appearance. This condition can cause serious health issues later on, such as life-threatening kidney problems that need to be treated as soon as possible.
• Female with male chromosomes (46, XY DSD): Some female children have male chromosomes (XY) but their external genitals may appear entirely female or unclear. In addition, the womb may or may not be present. The testicles may be absent or not properly formed. Several different causes are behind this condition. Androgen insensitivity syndrome (AIS) is one possible cause. With AIS, the body either ignores androgens or is not sensitive to them. For this reason, the child appears to be female. The testes usually remain inside the body and the womb does not develop.
• Mixed genitals and sex organs (46, XX Ovotesticular): This is a very rare type of DSD where the child has tissue from both ovaries and testicles. The genitals may appear female, male, or a mix of both. Children with this type of DSD have female chromosomes. Although the cause of this condition is not known, some cases have been linked to genetic material normally found on the Y chromosome that is misplaced on the X chromosome.
• Sex chromosome DSD: Some children have neither male nor female chromosomes. Instead, they may have only one X chromosome (XO), or they may have an extra chromosome (XXY). Their sex organs are, however, normally formed as either male or female. Those children may not go through normal sexual development at puberty. For example, a child with female sex organs may not start having periods, and may have small breasts.