Paediatrics: Management of sex development disorders

Disorder of sexual differentiation

Investigations

Laboratory

• Genetic sex determination: FISH for Y and X chromosomes; karyotype(takes 3–5 days).
• Serum electrolytes.
• Blood sugar (hypoglycaemia).
• Adrenal androgens: plasma testosterone; 17-OH progesterone; urine steroid profile; LH and FSH.
• Molecular genetic studies; blood (DNA).

If a male/mosaic karyotype is confirmed, further investigations are directed at establishing whether testicular tissue is capable of producing androgens:

• hCG stimulation test;
• testosterone: DHT ratio;
• androgen receptor binding studies;
• genital skin biopsy (fibroblast).

Imaging studies

• US scan pelvis: anatomy of urogenital sinus/vagina/uterus.
• US scan abdomen: renal anomalies.
• Urogenital sonogram.
• MRI.

Internal examination

• Examination under anaesthesia (+/– cystography).
• Laparoscopy.
• Gonadal biopsy.

Management

This is professionally challenging and requires a multidisciplinary team including the following:

• Paediatric endocrinologist.
• Neonatologist.
• Paediatric urologist.
• Gynaecologist.
• Geneticist.
• Radiologist.
• Psychologist.

Clinical biochemistry

Most infants presenting with a disorder of sexual differentiation will pre-sent with ambiguous genitalia at birth.

• Parents and their relatives will be anxious to know the sex of their newborn baby.
• Decisions about an infant’s sex (sex assignment) must be delayed until the multidisciplinary team has carried out a thorough assessment.
• Birth registration must be delayed until this has been completed and an agreement on sex assignment has been made with the parents.