Define Short Stature — Approach, Causes & Evaluation. Describe its investigations and management.

Definition

Short stature is a height below the 3rd percentile (or below −2 SD) for age and sex, OR a height velocity below the 25th percentile sustained over ≥ 6–12 months, OR a height significantly below the genetic (mid-parental) target.

B. Proportionate Pathological Short Stature

• Undernutrition — the commonest cause worldwide.
• Chronic systemic disease — CKD, congenital heart disease, chronic liver disease, malabsorption (coeliac disease), IBD, chronic infections (TB), poorly controlled asthma, chronic anaemia.
• Endocrine — growth hormone (GH) deficiency, hypothyroidism, Cushing syndrome, poorly controlled diabetes, precocious puberty.
• IUGR / small-for-gestational-age with failure of catch-up.
• Psychosocial (deprivation) dwarfism.

C. Disproportionate Short Stature (abnormal Us:ls Ratio)

• Skeletal dysplasias — achondroplasia (short limbs, high US:LS), spondyloepiphyseal dysplasia (short trunk).
• Rickets and other metabolic bone diseases.

D. Genetic / Syndromic

• Turner syndrome (screen every short girl with a karyotype — webbed neck, cubitus valgus, widely spaced nipples, delayed puberty).
• Down syndrome, Noonan syndrome, Prader-Willi syndrome, Russell-Silver syndrome.

Clinical Evaluation — History

• Birth weight/length, antenatal & perinatal events (IUGR, asphyxia).
• Growth records, age of onset of faltering, height velocity.
• Dietary history; chronic symptoms (diarrhoea, cough, polyuria); drug history (steroids).
• Parental heights & pubertal timing; consanguinity; developmental history.

Clinical Evaluation — Examination

• Accurate anthropometry (height, weight, arm span, US:LS, sitting height) plotted on charts.
• Calculate mid-parental height and height velocity.
• Dysmorphic features, goitre, signs of systemic disease, pubertal (Tanner) staging, fundus & visual fields (for a pituitary tumour).

Investigations (stepwise)

First-line screen:

• CBC, ESR; renal & liver function; venous blood gas / electrolytes.
• Thyroid function (TSH, T4); coeliac serology (anti-tTG).
• Bone age (X-ray left hand & wrist); urine routine / microscopy.
• Karyotype in every short girl (to exclude Turner syndrome).

Second-line (if screen normal / GH deficiency suspected):

• IGF-1 & IGFBP-3; GH stimulation (provocation) tests (clonidine, insulin, glucagon).
• MRI brain/pituitary if GH deficiency is confirmed (to exclude craniopharyngioma).
• Serum cortisol / overnight dexamethasone suppression if Cushing is suspected.

Management

• Treat the underlying cause — nutrition, gluten-free diet for coeliac, thyroxine for hypothyroidism, treat systemic disease.
• Recombinant human GH — for proven GH deficiency, Turner syndrome, chronic renal failure, Prader-Willi, and SGA without catch-up.
• Constitutional delay — usually reassurance; a short course of sex steroids in selected distressed adolescents.
• Psychological support; monitor the growth velocity on therapy.