Paediatrics chapters
Short stature
How to define and classify short stature, separate normal variants (familial short stature and constitutional delay) from disease, use bone age and growth velocity, and when to suspect growth hormone deficiency, hypothyroidism or Turner syndrome.
- Short stature is height below the 3rd (or 5th) centile for age and sex, judged against family height; a child under 3.5 SD or growing under 5 cm/year needs work-up.
- The two commonest causes are normal variants: familial short stature (short parents, normal bone age, normal timing of puberty) and constitutional delay (normal parents, delayed bone age, late puberty, normal adult height).
- Pathological causes show slow growth velocity: hypothyroidism, GH deficiency, Cushing syndrome, Turner syndrome, chronic disease, malnutrition, skeletal dysplasia; key tests are bone age, TFTs, karyotype in girls, IGF-1 and GH stimulation tests.
On this page
Overview
Short stature is one of the commonest reasons for referral to a paediatric endocrine clinic. Most short children are healthy and have a normal variant (familial short stature or constitutional delay). The task is to pick out the minority with disease, mainly by measuring growth velocity over time, comparing with parental heights, and checking the bone age. A normal growth pattern is good evidence of overall health.
Definitions
- Short stature: height below the 3rd (or 5th) centile for age and sex, taking ethnic background and family heights into account.
- Pathological short stature is usually more than 3.5 SD below the mean (Akbar, Nelson).
- Growth failure: a slow growth rate whatever the height; on a chart, the child crosses centiles downwards, with height velocity below the 5th centile for age.
- The lower limit of normal growth velocity from about 1 year to before puberty is roughly 5 cm per year (Akbar).
A short child growing at a normal rate is unlikely to have significant disease. A child whose growth rate is slow needs investigation, even if the height is still within the normal range.
Measuring growth properly
- Supine length from birth to 2 years; standing height (stadiometer, barefoot) after 2 years.
- Plot height, weight and head circumference on centile charts; serial measurements give growth velocity.
- Arm span and upper-to-lower segment ratio show body proportions.
| Age | Normal upper:lower segment ratio |
|---|---|
| Term newborn | 1.7 : 1 |
| 1 year | 1.4 : 1 |
| 10 years | 1 : 1 |
- High ratio (short limbs): untreated hypothyroidism, short-limbed skeletal dysplasias.
- Low ratio (long limbs): hypogonadism in adults (e.g. Klinefelter).
Mid-parental (target) height
Nelson: average the parents' heights and add 2.5 inches (about 6.5 cm) for a boy or subtract 2.5 inches for a girl; the normal range is about ±2 SD (about 10 cm).
Father 175 cm, mother 160 cm; average = (175 + 160) ÷ 2 = 167.5 cm
Boy: 167.5 + 6.35 ≈ 174 cm (range about 164 to 184 cm)
Girl: 167.5 − 6.35 ≈ 161 cm (range about 151 to 171 cm)
Classification by cause
| Group | Examples |
|---|---|
| Normal variants (commonest) | Familial (genetic) short stature, constitutional delay of growth and puberty |
| Prenatal | Small for gestational age / intrauterine growth restriction without catch-up (primordial), congenital infections |
| Nutritional | Malnutrition (the most important factor worldwide), iron or zinc deficiency |
| Chronic systemic disease | Coeliac disease, Crohn disease, chronic kidney disease, renal tubular acidosis, cyanotic heart disease, heart failure, cystic fibrosis, severe asthma, thalassaemia, sickle cell disease, chronic infection, poorly controlled diabetes |
| Endocrine | Hypothyroidism, GH deficiency, Cushing syndrome (usually from steroid treatment), poorly controlled diabetes, pseudohypoparathyroidism |
| Chromosomal and syndromes | Turner, Down, Noonan, Prader-Willi, Russell-Silver, Laurence-Moon-Bardet-Biedl |
| Skeletal dysplasias | Achondroplasia, osteogenesis imperfecta, spinal dysplasias |
| Metabolic | Rickets, mucopolysaccharidoses, glycogen storage disease |
| Psychosocial | Emotional deprivation (psychosocial dwarfism): functional, reversible GH deficiency |
Proportionate versus disproportionate
- Disproportionate (abnormal segment ratio or arm span): skeletal dysplasia (Akbar notes osteogenesis imperfecta as an exception); a skeletal survey helps.
- Proportionate: most endocrine, nutritional, chronic disease and familial causes; hypothyroidism is the endocrine exception, with infantile (short-limbed) proportions.
In endocrine short stature the child is usually overweight for height ("short and chubby"); in nutritional or chronic disease short stature, weight falls before height.
Normal variants compared
| Feature | Familial short stature | Constitutional delay | Pathological (e.g. GH deficiency, hypothyroidism) |
|---|---|---|---|
| Family history | Short parent(s) | Parent with late puberty ("late bloomer"), parents of average height | Usually none |
| Sex | Both | Boys much more often | Both |
| Growth velocity | Normal (over 4 to 5 cm/year) | Normal (low-normal) | Slow (under 5 cm/year) |
| Bone age | Equal to chronological age | Delayed (equal to height age) | Delayed (markedly) |
| Puberty | Normal age | Delayed | Often delayed |
| Final height | Short, but normal for family | Normal for family | Reduced if untreated |
| Treatment | Reassurance | Reassurance; short course of low-dose testosterone in selected boys | Treat cause |
Familial = "Family short, Fine bone age"; Constitutional = "Catches up, delayed bone age."
Constitutional delay
- Slow tempo of maturation; growth curve runs parallel to and below the centile lines, then late pubertal spurt (often 15 to 17 years), growth continuing to 18 to 20 years.
- Bone age delayed, matching height age.
- Reassurance is the main treatment; low-dose testosterone for 3 to 6 months in boys can bring puberty forward but does not increase final height. GH has no role.
Familial short stature
- Child sets a growth curve at or below the 5th centile by 2 to 3 years and follows it.
- Bone age normal; puberty on time; healthy on examination.
Pathological causes: key points
Hypothyroidism
- Marked growth failure (under 5 cm/year), markedly delayed bone age, overweight.
- Because it is easily treated, almost every short child should have T4 and TSH checked, even without symptoms.
- Treatment: thyroxine.
Growth hormone deficiency
- GH is pulsatile (mostly during sleep and exercise); its growth effect on bones is mediated by IGF-1 from the liver.
- Idiopathic (usually a hypothalamic GRF defect) is the commonest cause; others: brain tumours (craniopharyngioma), cranial irradiation, trauma, infection, midline defects (septo-optic dysplasia, cleft palate).
- Normal size at birth (GH is not needed for fetal growth); growth slows after 6 to 12 months.
- Newborn clues: hypoglycaemia, micropenis (gonadotrophin deficiency), prolonged jaundice.
- Older child: very short, slow growth (under 5 cm/year), chubby, immature "cherub" face, frontal bossing, flat nasal bridge, high-pitched voice, truncal fat, delayed bone age; intelligence normal.
Diagnosis
- Low IGF-1 and IGF-BP3 (screening; also low in malnutrition).
- GH stimulation tests (insulin hypoglycaemia, arginine, clonidine, levodopa, glucagon, exercise). Akbar's cut-offs:
| Peak GH | Interpretation |
|---|---|
| Over 10 ng/mL | Normal |
| 7 to 10 ng/mL | Partial deficiency or neurosecretory defect |
| Under 7 ng/mL on two tests | Classic GH deficiency |
- MRI of the hypothalamic-pituitary area in every case of hypopituitarism.
- Exclude hypothyroidism first: hypothyroid children can look falsely GH-deficient.
Treatment
- Recombinant human GH by daily subcutaneous injection; dose titrated to growth.
- A rise in growth velocity from under 5 to at least 7 to 8 cm/year confirms true deficiency; a poor response means checking the diagnosis or adherence.
- Other approved uses: Turner syndrome, chronic renal failure, Prader-Willi syndrome, SGA without catch-up (by 2 years), idiopathic short stature.
- Side effects: slipped capital femoral epiphysis and raised intracranial pressure (pseudotumour cerebri).
Laron syndrome is GH resistance (GH receptor defect): high GH, low IGF-1. GH injections do not help.
Hypothyroidism must be treated before GH tests are read, because a hypothyroid child can appear falsely GH-deficient.
Turner syndrome
- Consider in every short girl, even without typical features.
- 45,X or mosaic karyotype. Look for short stature, a broad (shield) chest with widely spaced nipples, increased carrying angle, high-arched palate and ovarian failure, with renal and aortic arch anomalies.
- Karyotype confirms; treat with GH early and oestrogen (then progesterone) at puberty.
Others
- Cushing syndrome: growth arrest with weight gain, delayed bone age; usually iatrogenic steroids.
- Psychosocial deprivation: functional GH deficiency that reverses when the child is moved to a caring environment.
- Chronic disease and malnutrition: slow growth from poor intake, losses and high metabolic demand; treat the disease.
Clinical approach
History
- Birth weight and gestation (SGA), pregnancy and neonatal problems.
- Parental heights; timing of parents' puberty (mother's menarche, father's growth spurt).
- Diet and psychosocial history.
- Symptoms of chronic disease (diarrhoea, breathlessness, polyuria), headache and vomiting (brain tumour).
Examination
- Accurate height, weight, head circumference, arm span, segment ratio; plot all.
- Dysmorphic features, digits and joints (syndromes, dysplasias).
- Goitre, signs of hypothyroidism.
- Tanner staging; genital anomalies (micropenis).
- Visual fields and fundoscopy (papilloedema, optic atrophy from a pituitary tumour).
- Teeth and nutritional status.
Investigations
Extensive tests are not needed when the history and examination point clearly to a familial or constitutional cause.
| Test | Looks for |
|---|---|
| Bone age (hand and wrist X-ray) | Delayed vs normal; height potential |
| Full blood count, ESR/CRP | Anaemia, chronic inflammation |
| Urine analysis (pH) | Renal disease, renal tubular acidosis |
| Urea, creatinine, electrolytes, bicarbonate, liver tests | Renal, hepatic disease, RTA |
| Calcium, phosphate, alkaline phosphatase | Rickets, hypoparathyroidism |
| T4 and TSH | Hypothyroidism |
| Coeliac serology (or jejunal biopsy) | Coeliac disease |
| Karyotype (girls) | Turner syndrome |
| IGF-1, IGF-BP3, then GH stimulation tests | GH deficiency |
| MRI brain | Pituitary or hypothalamic tumour, midline defects |
| Skeletal survey | Skeletal dysplasia (if disproportionate) |
Bone age interpretation
| Bone age vs chronological age | Suggests |
|---|---|
| Normal (equal) | Familial short stature, skeletal dysplasia |
| Delayed | Constitutional delay, hypothyroidism, GH deficiency, Cushing syndrome, chronic disease, malnutrition |
| Advanced | Precocious puberty, androgen excess (e.g. CAH: tall child, short adult) |
A delayed bone age means growth potential remains; it does not separate constitutional delay from endocrine disease. The growth velocity does.
Management and follow-up
- Treat the cause: thyroxine, GH, nutrition, gluten exclusion for coeliac disease, dialysis or transplant for renal failure, a better home environment for deprivation.
- Normal variants: explain and reassure; keep measuring growth to confirm a normal velocity.
- Psychological support for children with marked short stature.
- Follow-up: regular height on the same chart, growth velocity, bone age, puberty staging and response to treatment.
Expect: definition below the 3rd centile and pathology beyond 3.5 SD or growth under 5 cm/year; familial short stature (short parents, normal bone age, normal puberty) versus constitutional delay (delayed bone age, late puberty, normal adult height, boys); segment ratios 1.7, 1.4 and 1.0; disproportionate short stature pointing to skeletal dysplasia; overweight child with slow growth suggesting endocrine disease; TFTs in all short children; karyotype in every short girl; GH deficiency features (normal birth size, hypoglycaemia, micropenis, cherub face) and GH test cut-offs; Laron syndrome; GH therapy indications and side effects; psychosocial dwarfism.
Quick revision
- Below 3rd centile; worry if under 3.5 SD or velocity under 5 cm/year.
- Commonest causes: familial short stature and constitutional delay.
- Familial: short parents, normal bone age, normal puberty, short adult.
- Constitutional: delayed bone age and puberty, boys, normal adult height.
- Disproportionate = skeletal dysplasia; hypothyroidism gives infantile proportions.
- Short and fat = endocrine; short and thin = nutrition or chronic disease.
- First tests: bone age, FBC, ESR, urine, renal, calcium, TFTs, coeliac, karyotype in girls.
- GH deficiency: peak GH under 7 ng/mL on two tests; MRI pituitary.
- GH side effects: SCFE, pseudotumour cerebri.
- Turner: test every short girl.
Written by The House Job from standard references (Basis of Paediatrics by Pervez Akbar; Nelson Essentials of Paediatrics).
FAQ
What is the commonest cause of short stature?
Normal variants: familial (genetic) short stature and constitutional delay of growth and puberty, which together outnumber all disease causes.
How does bone age help?
A bone age equal to chronological age with normal growth suggests familial short stature; a delayed bone age suggests constitutional delay or an endocrine or chronic disease, which growth velocity helps separate.
Why test thyroid function in every short child?
Hypothyroidism can cause marked growth failure with few other symptoms and is easy to treat, so T4 and TSH are checked even when the child seems well.
Does growth hormone help constitutional delay?
No. These children reach normal adult height; reassurance is enough, with a short course of low-dose testosterone in selected boys to start puberty.