Growth disorder: Constitutional delay/Delayed puberty Flashcards
Define constitutional delay.
Defined as the lack of any pubertal signs ( secondary sexual characteristics, accelerated linear growth, increase in the secretion of sex hormones, maturation of gonads (testes in boys; ovaries in girls), and the potential for reproduction) by the age of 13 years in girls and 14 years in boys.
What happens in normal puberty?
Nocturnal increase in the amplitude and pulsatility of gonadotrophin-releasing hormone (GnRH) secretion from the hypothalamus.
Secretion of pituitary hormones LH and FSH (+other neurotransmitters, including GPR54, a Gprotein coupled receptor that is a ligand for kisspeptin, which is necessary for GnRH).
FSH stimulates Sertoli cells in the male, producing spermatogonia, and follicular cells in the female, resulting in ovulation. LH regulates testosterone and oestrogen production.
What are some causes of constitutional delay which involve normal gonadotrophins?
- Constitutional delay of growth and puberty (CDGP) is a term describing a temporary delay in the skeletal growth and thus height of a child with no physical abnormalities causing the delay. It is a variation of the normal timing of puberty rather than an abnormal condition. It may also be induced by dieting or excessive physical training.
- Chronic illness: Inflammatory bowel disease, cystic fibrosis, renal disease, severe asthma, CNS disorders (Langerhans cell histiocytosis, congenital defects).
- Anorexia nervosa, starvation, excess physical training (ballet, athletes)
- Deprivation.
What are some causes of constitutional delay which involve hypogonadotrophic hypogonadism.
Hypogonadotrophic hypogonadism, resulting from a lack of serum gonadotrophin production or action, and manifesting with an absence of spontaneous pubertal development. This occurs in patients with hypothalamo-pituitary disorders and in those with a functional delay (constitutional delay, underlying chronic disease, malnutrition, excessive exercise).
- Hypothalamo-pituitary disease: panhypopituitarism, intracranial tumours.
- Kallmann syndrome (LHRH deficiency, anosmia) and Prader-Willi syndrome.
- Hypothyroidism (acquired).
- Idiopathic.
What are some causes of constitutional delay involving hypergonadotrophic hypogonadism?
Hypergonadotrophic hypogonadism, resulting from gonadal disorders and manifesting with elevated serum gonadotrophin concentrations in the absence of pubertal signs at the appropriate age for puberty.
- Congenital: Turner syndrome (45X karyotype), Klinefelter syndrome (47XXY)
- Steroid hormone enzyme deficiency
- Acquired gonadal damage: chemotherapy, radiotherapy, trauma, torsion, autoimmune.
Explain the aetiology/risk factors for constitutional delay.
Constitutional delay: These children have delayed puberty, which is often familial, usually having occurred in the parent of the same sex. There is a similarity in the age at onset of puberty between girls and their mothers, especially with age of menarche.
Summarise the epidemiology of constitutional delay.
More common in boys.
What are signs and symptoms of constitutional delay?
Short stature and possibly slow pubertal development: small testes (boys), absent breasts (girls), absence of menarche (girls), absent pubic/axillary hair The condition may cause psychological upset. The onset of puberty can be induced with androgens or oestrogens.
What are some appropriate investigations for constitutional delay?
Bloods: FSH and LH (Laboratory measurement of serum FSH and LH concentrations will help to differentiate patients with hypogonadotrophic hypogonadism (low levels) and hypergonadotrophic hypogonadism (elevated levels), TFTs, androgen/oestrogen.
Radiology: Non dominant (usually left side) wrist X-ray (helps to estimate skeletal age).
Karyotyping.
What is the management for constitutional delay?
Monitor growth and for pubertal signs.
Psychosocial problems: Consider treatment with oxandrolone, a weak androgen, to improve growth velocity.
Greater concern: Short course of intramuscular testosterone (males) or oestrogen replacement therapy (females).
Chronic illness, malnutrition, eating disorder, excess exercise, stress: treat underlying condition.
What are potential complications associated with constitutional delay?
Psychological problems and short stature.
What is the prognosis of constitutional delay?
Excellent in constitutional delay where there is no underlying physical abnormality.
