Growth and Puberty: Short Stature Flashcards
What is short stature usually defined as?
Height below the second centile
How many children are shorter than the 0.4 centile?
Only 1 in 250
These children should be assessed for a cause
The rate of growth may be abnormal a long time prior to the child being below the second centile. How can this be identified?
From the child’s height falling across centile lines plotted on a height velocity chart
What is a sensitive indicator for growth failure?
Height velocity
What is a disadvantage of using height velocity calculations?
They are highly dependent on accuracy of height measurements - tend not to be used outside specialist growth clinics
How can the genetic expected height be calculated?
The mean of the father and mother’s height with 7cm added for boy and 7cm subtracted for a girl
The 9th to 91st centile range is given by +and- 10cm for boy and +and- 8.5cm in a girl
Most short children have short parents. What is this called?
Familial short stature
- but care should be taken that there is no inherited growth disorder e.g skeletal dysplasia
What is constitutional delay in growth and puberty?
A variation of normal growth
Presents as short stature in teenage years due to a delay in onset of puberty
Growth in childhood in lower limits, bone age delayed and onset of secondary sexual development delayed
Final growth height is normal
Usually FH of delayed growth and puberty
What percentage of children born small for gestational age or extremely premature, remain short?
About 10%
GH may be needed if insufficient catch up growth by 4 years
What chromosomal disorders/syndromes are associated with short stature?
Down syndrome - usually diagnosed at birth
Turner syndrome
Russell-Silver
Noonan
Last 3 may present with short stature and minimal symptoms
Nutritional/long term illness is a relatively common cause of abnormal growth. These children are usually short and…
Underweight - their weight is on the same or a lower centile than their height
What may inadequate nutrition be due to?
Insufficient food
Restricted diet
Poor appetite associated with long term illness
Increased nutritional requirement from increased metabolic rate
What chronic illnesses present with short stature?
Coeliac disease - can have short stature without GI symptoms
Crohn’s
CKD - may be present in absence of a history of renal disease
CF - malabsorption, recurrent infections, increased work of breathing, reduced appetite
CHD - increased work of breathing
Children subject to emotional and physical deprivation may be short and underweight and show delayed puberty. What usually happens if placed in a nurturing environment?
Catch up growth
What endocrine causes of short stature are there?
Hypothyroidism
GH deficiency
IGF1 deficiency
Steroid excess
What typically causes hypothyroidism in children?
Autoimmune thyroiditis
How is growth affected in cases of hypothyroidism?
Growth failure
Excess weight gain
May go undiagnosed for many years and lead to short stature
When hypothyroidism is treated, what can occur?
Catch up growth occurs rapidly
Often with a rapid entry into puberty - this can limit final height
Does congenital hypothyroidism, with treatment result in any abnormality of growth?
No
GH deficiency may be isolated or secondary to…
Wider pituitary dysfunction
Pituitary function may be abnormal in congenital mid facial or midline defects or due to a craniopharyngioma (tumour affecting pituitary region), a hypothalamic tumour, trauma, meningitis, cranial irritation
How does a craniopharyngioma present?
In late childhood
May cause abnormal visual fields - bitemporal hemianopia as it impinges on optic chiasm
Optic atrophy or papilloedema on fundoscopy
What is Laron syndrome?
A condition due to defective GH receptors resulting in GH insensitivity
Patients have high GH levels, but low levels of the downstream active product of GH - IGF1
Where is IGF1 produced?
Liver and growth plate
Is corticosteroid therapy a potent growth suppressor?
Yes
Can some growth suppression be seen even with relatively low doses of inhaled or topical steroids?
Yes
Is noniatrogenic Cushing’s syndrome rare in childhood?
Yes
Does normalisation of height and weight occur once steroids stopped?
Yes
What rare conditions cause extreme short stature?
Abnormalities in the gene called short stature homeobox (SHOX) located on the X chromosome, leads to severe short stature and skeletal abnormalities when present on both copies of gene
In Turner syndrome there is thought to be absence of one SHOX gene
How is disproportionate short stature measured?
Sitting height - base of spine to top of head
Subischial leg length - subtraction of sitting height from total height
Limited radiographic skeletal survey to identify the skeletal abnormalities
Conditions with abnormal body proportions are rare and may be due to…
Disorders of the formation of bone e.g skeletal dysplasia
- they include achondroplasia and other short limb dysplasias
The back may be short from severe scoliosis or some storage disorders e.g the mucopolysaccharidoses
What is achondroplasia?
Normal sized torso, but shorter limbs
How is GH deficiency treated?
Biosynthetic GH given by subcutaneous injection, usually daily
It is expensive
Management undertaken at specialist centres
Best response seen in those with most severe GH deficiency
What are some other indications for biosynthetic GH ?
Turner syndrome Prader-Willi syndrome CKD SHOX deficiency Intrauterine growth restriction or small for gestational age with failure to catch up
What investigations should be considered for short stature?
X-ray of left hand and wrist for bone age - some delay in constitutional delay do puberty, marked delay for hypothyroidism or GH deficiency
FBC - anaemia in coeliac or Crohns
Creatinine and electrolytes - CKD
TSH - raised in primary hypothyroidism
Karyotype - Turner syndrome (45XO) and other chromosomal disorders
EMA and anti-tTTG - coeliac disease
CRP and ESR - raised in crohns
Growth hormone provocation test - GH deficiency
IGF-1
Cortisol and dexamethasone suppression test - Cushing’s syndrome
MRI - craniopharyngioma or intracranial tumour
