Short Stature in Children
Short stature is a common reason for paediatric referral and is defined as a height below the 2nd centile on a standard UK growth chart. A single height measurement is less useful than a pattern of growth over time, so monitoring height velocity is crucial. A child’s height is a sensitive marker of their overall health and nutrition.
Aetiology and Classification
Causes of short stature can be classified into two broad categories:
Normal Variants: These are the most common causes and do not represent an underlying pathological condition.
Familial Short Stature: The child’s height is consistently below the 2nd centile, but their height velocity is normal, and their final height is consistent with their parents’ short stature.
Constitutional Delay of Growth and Puberty (CDGP): This is a delay in the timing of the pubertal growth spurt. The child’s height velocity is normal, but they will have a delayed bone age. They will eventually achieve a normal adult height.
Pathological Short Stature: These are caused by an underlying medical condition.
Chronic Disease: Coeliac disease, chronic kidney disease, inflammatory bowel disease, or severe asthma can all cause short stature. In these cases, weight is often disproportionately affected before height.
Genetic Syndromes: Conditions like Turner syndrome, Down syndrome, or Prader-Willi syndrome have specific growth patterns that often result in short stature.
Endocrine Causes: Growth hormone (GH) deficiency and hypothyroidism are key endocrine causes.
Skeletal Dysplasia: A group of disorders affecting bone growth, such as Achondroplasia.
Clinical Assessment
History: Take a detailed history of the child’s growth since birth. Ask about any chronic illnesses, medications, and diet. A key part of the assessment is to plot the parents’ heights to calculate the mid-parental height (MPH), which gives an estimate of the child’s genetic height potential.
Examination:
Accurate Measurements: Use a stadiometer to get an accurate height measurement. Plot serial measurements on a growth chart to assess height velocity.
Proportions: Assess the child’s body proportions by measuring the upper-to-lower segment ratio and arm span. This can help distinguish between proportional and disproportionate short stature.
Pubertal Staging: Assess the child’s pubertal stage using Tanner staging.
Dysmorphic Features: Look for any syndromic features that might suggest a specific genetic condition.
Investigations
First-line Investigations: If a pathological cause is suspected, initial tests include a full blood count, U&Es, liver function tests, thyroid function tests, and a coeliac screen.
Bone Age: An X-ray of the left wrist is a key investigation to determine the bone age. In CDGP, the bone age is delayed, while in familial short stature, it is normal.
Endocrine Investigations: If GH deficiency is suspected, a GH provocation test is performed. This is a dynamic test that measures the child’s GH response to a stimulating agent.
Genetic Testing: A karyotype or microarray is recommended if a genetic syndrome like Turner syndrome is suspected.
Management
Normal Variants: No treatment is required, but reassurance and regular monitoring are essential.
Treating the Underlying Cause: For pathological causes, management involves treating the underlying condition (e.g., steroid replacement for adrenal insufficiency, levothyroxine for hypothyroidism, or a gluten-free diet for coeliac disease).
Growth Hormone (GH) Therapy: GH replacement is used to treat GH deficiency. It is also licensed for other conditions, such as Turner syndrome, Prader-Willi syndrome, and children with short stature born small for gestational age (SGA) who have not shown catch-up growth.