Note puberty lines on RCPCH growth charts, for starting puberty (girls 8), delayed beginning (girls 13, boys 14) and completing (girls 16, boys 17). Delayed completion (especially menses) also needs investigation. Also a shaded triangle for short boys and girls during this time, to remind that probably ok if puberty not yet started, but potentially a problem if nearly completing.
In girls, rule out Turner’s syndrome.
Otherwise look for evidence of dysmorphism, that might suggest another chromosomal or genetic issue, and evidence for broader pituitary issue (midline facial defects, visual defects, poor growth, child looks younger than their age).
If not central, then must be gonadal issue – check testes, do USS scan to look at ovaries.
Blood tests then to assess pituitary hormones, particularly FSH/LH, plus oestradiol and testosterone.
In girls with amenorrhoea but normal pubertal progression, haematocolpos due to imperforate hymen presents with abdominal pain, urinary retention.