Disorders of Sex Development (Children)

Disorders of Sex Development encompass a diverse range of diseases which present in a newborn with atypical external genitals, or in an adolescent with atypical sexual development during the pubertal years. These clinical situations are difficult to manage and an initial comprehensive evaluation is necessary to:

• Develop a logical plan for investigation
• Arrive at a diagnosis and assign the appropriate gender
• Organise the medical, surgical, and psychological intervention in a multi-disciplinary setting

Disorders of Sex Development can be due to many causes, which include abnormalities in the sex chromosomes, genetic mutations affecting the development of the gonads (testes or ovary), inherited deficiencies in the enzymes for the production of sex hormones and androgen (male sex hormones) receptor unresponsiveness.

Babies with Disorders of Sex Development may be born with genitals that are not fully formed. On occasion, parents may expect either a boy or a girl based on the chromosomal analysis performed during pregnancy. However, the external genitals are not what is expected when the baby is born. This can lead to parental confusion and much distress.

For older children, the Disorders of Sex Development can surface:

• When a girl has delayed puberty.
• If a girl does not experience her menses despite puberty progressing for some time.
• If a girl starts developing male features during puberty.
• If a boy fails to complete puberty.

Disorders of Sex Development need to be investigated to determine the cause and to make the crucial decision as to whether to bring up the child as a boy or a girl. These investigations will include blood tests to check for hormonal levels and often, imaging studies to assess for the presence of female organs such as the uterus.

The treatment of children with Disorders of Sex Development depends on the underlying cause. In severe cases of Congenital Adrenal Hyperplasia (CAH), which is the most common of these disorders, treatment with steroid replacement therapy is essential for survival. CAH is a group of inherited genetic disorders in which the affected child does not have one of the enzymes needed by the adrenal glands to produce one or more of three steroid hormones:

• Cortisol which regulates your body's response to illness or stress
• Mineralocorticoids which regulate sodium and potassium levels
• Androgens which are male sex hormones

Surgery is often required for the external genitalia in accordance with the chosen sex of rearing, as well as to remove the gonad contrary to the sex of rearing. Some children will also need sex hormone replacement during puberty.