Growth hormone is responsible for stimulating cell reproduction and the growth of organs, muscles, bones and height; it stimulates the release of insulin-like growth factor 1 (IGF-1) by the liver, which is also important in promoting growth in children and adolescents

Aetiology

• Congenital growth hormone deficiency results from a disruption to the growth hormone axis at the hypothalamus or pituitary gland
  • It can be due to a known genetic mutation such as the GH1 (growth hormone 1) or GHRHR (growth hormone releasing hormone receptor) genes, or due to another condition such as empty sella syndrome where the pituitary gland is under-developed or damaged
• Acquired growth hormone deficiency can be secondary to infection, trauma or interventions such as surgery
• Growth hormone deficiency can occur in isolation or in combination with other pituitary hormone deficiencies like hypothyroidism, adrenal insufficiency and deficiencies of the gonadotrophins (LH and FSH)

Clinical features

Growth hormone deficiency may present at birth or in neonates with:

• Micropenis (in males)
• Hypoglycaemia
• Severe jaundice

Older infants and children can present with:

• Poor growth, usually stopping or severely slowing from age 2-3
• Short stature
• Slow development of movement and strength
• Delayed puberty

Investigations

• Growth hormone stimulation test
• Other investigations:
  • Test for other associated hormone deficiencies, for example thyroid and adrenal deficiency
  • MRI brain for structural pituitary or hypothalamus abnormalities
  • Genetic testing for associated genetic conditions such as Turner syndrome and Prader–Willi syndrome
  • X-ray (usually of the wrist) or a DEXA scan can determine bone age and help predict final height

Management

• Daily subcutaneous injections of growth hormone (somatropin)