Summary of findings
Report each measurement with its centile or z-score and a percentage of expected, then give the overall pattern.
Emeka is a 9-month-old boy. His weight is 6 kg against an expected 9 kg — 67% of expected, below −3 SD. His length is 62 cm against 72 cm, 86% of expected, below −3 SD. His head circumference is 40 cm against 44 cm, below −2 SD. All three are reduced, with the head affected least. This is global growth failure with relative head sparing; my concern is chronic undernutrition or an underlying chronic illness, and I would also consider a congenital cause because the head is small.
Differential diagnoses
| Finding | Causes |
|---|---|
| Upper-to-lower segment ratio above normal (short limbs) | Achondroplasia and other skeletal dysplasias, rickets, untreated hypothyroidism, Turner syndrome |
| Ratio below normal (long limbs) | Marfan syndrome, Klinefelter syndrome, homocystinuria, delayed puberty or hypogonadism |
| Arm span more than 5 cm above height | Marfan syndrome, Klinefelter syndrome |
| True limb length unequal | Hip or femur disease, growth plate injury, hemihypertrophy (Beckwith–Wiedemann), Klippel–Trénaunay syndrome, neurofibromatosis, vascular malformations |
| Only apparent length unequal | Pelvic tilt from scoliosis or a hip contracture |
| Weight, length and head all small from birth | Congenital infection, fetal alcohol exposure, chromosomal disorders |
Normal segment ratios: about 1.7 at birth, 1.3 at 3 years and 1.0 by about 7–10 years. Arm span is slightly less than height in young children, equal in adolescence and a few centimetres more in adult men.
Investigations
- Growth chart review — serial points and growth velocity matter more than one reading
- Bone age (left hand and wrist X-ray) — delayed in constitutional delay, hypothyroidism and malnutrition; normal in familial short stature
- Full blood count, urea and electrolytes, calcium, phosphate and alkaline phosphatase — chronic kidney disease, rickets
- Thyroid function
- Karyotype in any short girl, and where dysmorphism is present
- Coeliac serology, HIV test and stool studies where there is diarrhoea or poor weight gain
- Skeletal survey where limbs are disproportionate
Treatment
Treatment follows the cause. The immediate step is nutritional: classify by WHO criteria, start feeding support, treat infection and deficiencies, and review growth monthly. See Growth assessment.
Examiner questions
References
- Kliegman RM, St Geme JW, Blum NJ, Tasker RC, Wilson KM, et al., eds. Nelson Textbook of Pediatrics. 22nd ed. Philadelphia: Elsevier; 2025.
- WHO Multicentre Growth Reference Study Group. WHO Child Growth Standards: length/height-for-age, weight-for-age, weight-for-length, weight-for-height and body mass index-for-age. Geneva: WHO; 2006.
- World Health Organization. WHO guideline on the prevention and management of wasting and nutritional oedema (acute malnutrition) in infants and children under 5 years. Geneva: WHO; 2023.