There are many types of disorders of sexual differentiation (DSD) and atypical genitalia, and the symptoms each child experiences will vary greatly based on the type and severity of the disorder. Usually, these symptoms are picked up during fetal ultrasounds or shortly after birth upon physical examination. Some symptoms may include an enlarged clitoris which may take on an appearance of a small penis, a vaginal opening may appear closed, cloacal anomaly, hypospadias
, or a scrotum that appears empty or separated. There are other features that may also be found.
A DSD is a diagnosis that can be both difficult to understand and explain to family members who are close to the child. It is important for families to educate themselves on the child’s specific disorder. The disorders below are some of the most common disorders of sex differentiation that cause atypical genitalia. There are other syndromes that can cause atypical genitalia and children with those disorders will also be seen at the CHOC Urology Center.
Congenital Adrenal Hyperplasia
Congenital adrenal hyperplasia (CAH) is a genetic disorder in which the adrenal gland over produces androgens, a male hormone. Due to this, a child born with CAH will likely have genitalia that does not appear typical. With appropriate medical, surgical and psychosocial support, children with CAH can lead full and healthy lives and enjoy a normal life expectancy. Learn more about CAH and its treatment at CHOC Children’s
Mixed Gonadal Dysgenesis
Mixed gonadal dysgenesis occurs in children who have a chromosomal abnormality that causes them to be born with two different gonads—an undescended testis and a dygenetic (malformed) “streak” gonad. Because these two gonads do not produce normal sex hormones, the child’s sexual organs do not develop as they should. The external genitalia on these children will vary between normal appearing female and normal appearing male. There is a wide range of internal and external features for these children and each case is handled individually in order to assign the most appropriate sex for the child.
Although less common then the two DSD above, the following disorders are also treated at the CHOC Urology Center Disorders of Sexual Differentiation Program.
Androgen Insensitivity Syndrome
Children with androgen insensitivity syndrome have a 46, XY karyotype for a normal male. The cells within the body in these children do not respond to the male sex hormone, androgen (testosterone). This will often cause the child to display female characteristics despite being genetically male. There are varying degrees to this disorder. A child may be completely androgen insensitive, which causes the child to appear completely female in their external genitalia or they may be partially insensitive in which the genitalia may not look clearly male or female at birth.
Androgen insensitivity syndrome is an X-linked recessive inherited genetic disorder. This means that male children born to mothers who carry the gene for this disorder have a 50% chance of having the disorder. Females born to mothers who carry the gene have a 50% chance of carrying the gene and passing it down to their children in the future.
Pure Gonadal Dysgenesis
Children with pure gonadal dysgensis syndrome have a 46, XY karytope of a normal male but have underdeveloped gonads and both internal and external female genitalia.
Children with 5-alpha-reductase deficiency have a 46, XY karyotype of a normal male but have a deficient enzyme (5-alpha reductase) that prevents the body from being able to change testosterone into dihydrotestosterone. Dihydrotestosterone is needed to make a male fetus masculine. This deficiency is inherited by an autosomal recessive gene. This means that both the biological mother and father must carry the gene for the deficiency and pass it onto the child. If both the mother and father carry the gene, then each of their pregnancies will have a 12.5% chance of be affected. Female children will not be affected.
CHOC works directly with families to provide medical, surgical and pyschological support. Families looking for additional education, information and support may learn more about CAH at the CARES Foundation website
. (CHOC does not endorse the information found at this or other sites.)