Pediatric Abnormal Genitalia

Angry baby

Abnormal genitalia in infants are often described as "ambiguous genitalia" because their malformations can make it difficult to determine what sex a child is. During the early stages of embryonic development, the gonadal tissue, which will eventually become the ovaries or the testes is undifferentiated and could develop into either one.

Humans have 46 chromosomes including two sex chromosomes. A normal female has XX chromosomes, while a normal male has XY chromosomes. They determine what the gonads become. Once the gonads begin developing into testes or ovaries, the rest of the reproductive tract begins developing into the appropriate organs. Various hormonal and genetic factors can affect this development, and if something goes wrong, ambiguous genitalia can result.

Conditions involving ambiguous genitalia are surprisingly common and occur in one of 4500 live births. While some youngsters with ambiguous genitalia have other congenital defects, most are healthy. Common treatments for patients with abnormal genitalia include surgery and hormone replacement therapy.

Categories of Ambiguous Genitalia Conditions

Conditions with ambiguous genitalia are often called intersex conditions. A newer label for them is "disorders of sex development" or DSD.

Some types of ambiguous genitalia are caused by abnormal sex chromosomes. Some patients have only one X chromosome, and others have extra sex chromosomes. Other patients have a mixture of chromosome combinations in their cells. A few rare individuals are hermaphrodites with a combination of ovarian and testicular tissue.

Other patients have normal sex chromosomes, but they still have ambiguous or abnormal genitalia. These people have the expected XX or XY chromosomes but their genitalia failed to develop normally. In some cases, they develop some of the physical traits of the opposite sex.

Congenital Adrenal Hyperplasia

Congenital adrenal hyperplasia or CAH is the most common cause of ambiguous genitalia in girls and occurs in one of 15,000 births. This condition can, occur in both girls and boys. It is typically caused by a defect in an enzyme called 21-hydroxylase that helps produce cortisol. Consequently, the adrenal glands produce an abnormally low amount of cortisol. The disorder can also affect the production of other hormones including testosterone and aldosterone.

CAH comes in two main forms: classic and non-classic. Classic CAH is a more severe form and can be life threatening. The adrenal glands inability to produce enough cortisol can cause "an adrenal crisis", in which the patient develops extremely low levels of potassium and sodium in their blood. Symptoms of an adrenal crisis include dehydration, vomiting, diarrhea, abnormally low sugar levels in the blood, and shock. If not treated immediately, an adrenal crisis can kill.

Classic CAH, which is also called salt-wasting or salt-losing CAH, produces symptoms that are obvious from birth or early childhood. Girls with the condition will have ambiguous genitalia including an enlarged clitoris, while boys are born with an enlarged penis. Children with classic CAH will also undergo puberty prematurely. They will grow rapidly as children, but stop growing early on and thus wind up as short adults. They will also be sterile.

The symptoms of non-classic CAH are less severe, and the patients do not suffer adrenal crises. These youngsters may not be diagnosed with CAH until they reach puberty, which will also occur abnormally early. Girls will develop masculine features like a deep voice and lots of body hair. They will also have irregular or no menstrual periods, and they will be sterile. Patients of both sexes will be short and prone to obesity, severe acne, and low bone density.

Klinefelter Syndrome

Klinefelter Syndrome is a comparatively common chromosomal disorder that affects only males. Patients with the condition have an extra X chromosome, so they are XXY rather than the normal XY. They usually have small testes that produce little testosterone. Consequently, they experience a delayed or incomplete puberty. They also develop feminine breasts and little body or facial hair. Some patients will also have undescended testes located in the pelvis or abdomen, an abnormally small penis, and /or a urethra that opens on the underside of the penis. They are also sterile.

Patients with Klinefelter Syndrome also tend to be unusually tall. They can also have learning disabilities and be late in learning how to talk.

Turner Syndrome

Turner Syndrome has the distinction of being the only survivable chromosomal disorder in which the patient has fewer than 46 chromosomes. A person with Turner Syndrome has only one X chromosome and is thus XO rather than XX.

While short stature is the most common symptom and becomes evident by the time the patient is five years old, girls with Turner Syndrome also have degenerate and non-functional ovaries. Consequently, patients need hormone therapy to induce puberty, and the vast majority is sterile.

About a third to half of the patients is also born with heart defects, with the most common being coarctation or narrowing of the aorta. Other common symptoms include a webbed neck, kidney problems, and swelling of the hands and feet.

Androgen Insensitivity Syndrome

In androgen insensitivity syndrome, the patient is genetically male, but their body is either partially or completely unable to respond to a male hormone called androgen. In the complete form of androgen insensitivity syndrome, the patients body cannot use androgen at all and they therefore look female. They do not have a uterus. They have undescended testes and little or no pubic hair.

In the partial form, the patient can use some androgens. They can look like normal females, normal males, or have a combination of male and female traits. They are infertile and tend to develop unusually large breasts at puberty.