short stature
DESCRIPTION
A basic presentation for orientation of undergraduate and postgraduate studentsTRANSCRIPT
Short Stature
A detailed review
By
Saptharishi L G
Napoleon Bonaparte
Definition
Failure To Thrive Vs Short Stature
FTT – primarily poor weight gain in infants & young children
FTT – linear growth may be secondarily affected
SS – primarily subnormal linear growth thru’out childhood & adolescence
Approach
Approach to a child presenting to OPD with complaints of short stature
IDIOPATHIC short stature
DEFN ‘heterogeneous state that encompasses individuals
of short stature, including those of FSS, for which there is currently No recognized cause’
‘condition in which the height of an individual is > 2 SD score (SDS) below the corresponding mean height for a given age, sex, and population group without evidence of systemic, endocrine, nutritional, or chromosomal abnormalities’
Steps in assessment
Accurate ht measurement
Assessment of body proportions
Assessment of height velocity
Compare with population norms
Compare with genetic potential
Sexual Maturity Rating
Calculation Of Genetic Potential
Underlying conceptGrowth until 2 yrs : 66% drift across centiles2 yr onwards : ‘Growth Channels’
Mid Parental Height
Estimated Target Height
Target Height Range
Practical demonstration
Bone age
Aka skeletal age
Two internationally accepted methodsGruelich – Pyle atlas methodTanner & Whitehouse (TW2) method
Underlying concept – further growth potential
Usefulness in short stature
Recent Korean study comparing bone age in FSS Vs CDGP
CAUSES OF SHORT STATURE
Familial short statureComes from a short but otherwise normal family
One or both parents (and usually few other family members) 1.5 to 2 SD below mean ht
Growth channel is low but parallels normal curve
If GV is low or stature is extremely low out of keeping with the family pattern, Suspect other problems
NORMAL bone age IMPLICATION
FSS contd…
Etiology:Not clearClassified under ISSSubtle disorders of GH or its receptors- beyond
sensitivity of tests ??Neuro-secretory dysfunction : abnormal release
pattern but normal response to testing
ManagementCounselling & Reassurance
Constitutional delay in growth & adolescence
Aka CDGP, CDGD
Also considered a normal variant
Delayed onset of puberty & delayed growth spurt
H/o delayed puberty/ growth spurt in one or both parents (or other family members)
The final stature of that family member is NORMAL
CDGA contd..
Delayed bone age ‘Room for growth’
Subtle dysregulation of GH secretion?
DDx – Chronic illness, Panhypopituitarism
Differentiated by GnRH testing / LH assay
MANAGEMENT:Reassurance & CounsellingRole of short course of low-dose sex steroidsRole of GH therapy
Endocrine causes
GH deficiencyCongenital – with midline defects, with pituitary
agenesis, genetic defectsAcquired – Tumors, LCH, Infxns, trauma,
hydrocephalus, autoimmune, psycho-social, radiation
Laron dwarfism
Hypothyroidism
Glucocorticoid excess – endo and exogenous
DM / DI /Hypophosphatemic rickets
GH deficiency
Severe GHD : 1 in 4000Truncal obesity with ‘fat marbling’ / MICROPENISCrowding of mid-facial features with cherubic faciesHigh pitched voice / poor musculature / adiposityDelayed puberty Inadequate response on stimultn test (<7 mU/L)
Partial GHD : 7 -15 mU/L reponse on testing
Disorder of hypothalamic release of GHRH
GHD contd..
Any case of GHD, Neuro-imaging (MRI)Midline defects – septo-optic dysplasia, absent
septum pellucidumAny compressive lesions / tumors / hydrocephalus
NOTE : GH biosynthesis affected in primary hypothyroidism and celiac diseae
NOTE : GH testing – only in an euthyroid individual
Management : GH 15 -21 U (5-7mg/sq m/wk) in daily SC divided doses.
Larger doses (10 mg/sq m/wk) Turner’s and CRF
Placebo effect of GH – considerable (latest studies)
GH provocation testing
Screening – post exercise / 3- 4 hr post prandial / 1 hr after sleep onset
Pharmacological – Clonidine / ITT /arginine / glucagon
Miscellaneous – Physiologic sleep studies / urinary GH
Insulin Hypoglycemia Tolerance Testing85 % Normal children > 15 mU/L after 30 -60 minPotentially dangerous – expert endocrinologist
Role of Urinary GH testing – non invasive but how useful?
Hypothyroidism
Congenital or acquired (IDD/auto-immune)
Impaired linear growth + Goitre + Relative obesity
O/E : Bradycardia, dry hair/skin, delayed reflexes
Classical history of dry skin / constipation / cold intolerance not frequent in children
BONE age – significant delay
Rx – Thyroxine replacement
Corticosteroid excess
Endogenous – Cushing syndrome / cushing disease / adrenal tumor
Mostly exogenous – in our settings (Chooran) / prescribed steroids
Cotinues to gain wt at a rapid rate despite a fall in ht velocity (compare with exogenous obesity)
24 hr urine sample for cortisol testing
Treat primary cause
Disproportionate Short stature
Innate failure of bone or cartilage to grow normally
Usually inherited (AD) with clear-cut family history
NOTE : In these children, Bone age NOT reliable
Achondroplasia / Hypochondroplasia Characteristic radiologic findings with Increased US/LS
ratio Progressive deceleration of growth in infancy Humerus & femur – particularly short 125 cm /131 cm – final stature
Other osteochondrodysplasias
Chromosomal disordersTurner syndrome
SHOX gene (also plays role in ISS)SS + ovarian failureCharacteristic features of TurnersHigh dose GH therapySeparate growth charts
Prader Willi – uniparental disomy
Down syndrome – independent of hypothyroidism
Russel- Silver (primordial dwarfism)
Bloom / Williams / Fetal alcohol / Fanconi / LMB
Emotional deprivation
Aka deprivation dwarfism / psychosocial dwarfism
Two types – with food deprivation / Pure emotional
Height age < weight age
May mimic hypopituitarism- abnormal GH response to testing
Rapidly normalizes after initiating therapy
When to suspect ? History – typical . Good social history required ‘Frozen watchfulness’ & lack of emotional bonding Munchhausen by proxy
Nutritional
MOST common cause in INDIA
Chronic PEM / Under nutrition
Cause – poverty
Weight age < Height age
3 day diet record – prospective
Dietary management as per protocol
Chronic diseases
Why short stature ?? Poor appetite / poor intake – IBD / renal dysfunction Poor absorption – Malabsorption syn., Celiac disease Medications used – Bronchial asthma Chronic acidosis - RTA Secondary endocrine dysfunction
Typical history
SS may be the presenting feature of a chronic disease esp IBD, celiac disease and renal dysfunction
Rx– primary disease ; GH therapy in CRF
HOW TO INVESTIGATE A CHILD WITH SHORT STATURE ??
RED FLAGS in short stature
Height > 2-2.5 SD below mean for age
Subnormal growth velocity
Abnormal body proportions
Abnormal Height : weight ratio
Dysmorphic features
Goitre
Abnormal CNS & eye findings
GROWTHHORMONE
Role & Issues
Role of Growth Hormone
Placebo effect of GH
What is the response to GH ? >90% children with GHD achieve adult ht within their
target range ht Response in CRF & Turner’s is also prominent
Side effects of GH therapy Glucose intolerance, Hyperinsulinism, hyperlipidemia,
Hypertension, Type II DM, Benign intracranial hypertension
When to avoid GH ? Chromosome fragility syndromes
UPCOMING CONCEPTS>>>
Actually how advantageous is tall stature ??
How to identify ideal ht for a person ?
Are there any benefits of ‘pushing a child into normalcy’ ?
Psychosocial benefits of Tall stature
Pitfalls of the concept of GENETIC POTENTIAL
Child –also inherits an ‘environment’
Possibility of an unrecognized & untreated growth disorder in parents
GH deficiency / skeletal dysplasia / pseudohypoparathyroidism must be excluded