Short Stature Flashcards
Define short stature
height of 2+ standard deviations below the mean for children of the same age, sex, and, ideally, race and ethnicity;
or an adult height of 4’10″ (147 cm) or less
Types of short stature
Proportionate short stature:
limbs proportionate to trunk;
seen in familial short stature
Disproportionate short stature:
limbs disproportionately short compared to trunk; seen in cases of skeletal dysplasia
What is the normal paediatric growth rate
increased by 50% at 1 year of age
doubles at 4 years of age
and triples at 13 years of age
Different types of causes of short stature
Nonpathological
Prenatal disorders
Endocrine
Gastrointestinal disease
Renal disease (chronic renal failure)
Pulmonary disease
Cardiac disease and chronic oxygen deficiency
Rheumatological diseases (juvenile arthritis)
Metabolic diseases
Immunologic diseases
Genetic
Neoplasms
Psychosocial and psychological
Non pathological causes of short stature (3)
Familial short stature/hereditary.
- most common
- Inheriting short stature from parents
- Normal development
- skeletal age= chronological age
Constitutional growth delay
-2nd most common
-history of one/both parents with delayed development
skeletal age is younger & delayed puberty
normal adult height after puberty is complete
Idiopathic short stature
- Dg of exclusion when other condition’s absent
- Height of at 2 standard deviations below the mean
Endocrine causes of short stature
Congenital hypothyroidism
-PP: Sporadic thyroid dysplasia/ aplasia
hereditary defects in thyroid hormone synthesis.
Peripheral resistance to thyroid hormones
Leads to cretinism if unrx
Cretinism: ↓skeletal age, short stature, ↓ intellect
Pseudohypoparathyroidism
=Albright hereditary osteodystrophy
-autosomal dominant PTH resistance=
-Short stature, obesity, round face, subcutaneous ossification, brachydactyly
Growth hormone deficiencies
-d/2 hypopituitarism causing growth retardation
↓ bone density and muscle atrophy
-short stature and weak muscles
Congenital adrenal hyperplasia
- 21β-hydroxylase deficiency
- Vomiting and dehydration in 1st weeks of life
- Initially above average->adult stature below average
- Cushing’s disease is rare in children.
- d/2 glucocorticoid therapy=iatrogenic Cushing’s syndrome
- Excessive-weight-for-height
Gastrointestinal & renal causes of short stature
Gastrointestinal disease
- IBD & Celiac disease
- malnourishment & malabsorption
- Poor-weight-for-height
chronic renal failure
- Mineral bone disorder
1) vitamin D is not turned into calcitriol, reduced calcium lvls (secondary hypoparathyroidism). 2)phos rises causing ca2+ in blood to decrease, reduces PTH and draws calcium out of the bones, which weakens them) - Chronic anemia d/2reduced EPO
- Anemia of chronic kidney disease reduces growth & Rickets (bone deformities, impaired growth)
Pulmonary disease causing short stature
Asthma
pp:
1)Disturbed skeletal maturation by hypersensitivity dependant imbalances of local and systemic growth factors
2)iatrogenic cushing’s from glucocorticoid therapy of asthma
short stature in atopic children 2–5 times higher
Cystic fibrosis
PP:Mutated CFTR gene (defective chloride channel) → accumulation of secretions and blockage of exocrine glands → chronic inflammation → damage of bowel and lungs
Poor food intake
Maldigestion and malabsorption
Chronic infections, increased
-short stature more likely from malabsorption & increased E requirements
Rheumatologic causes of short stature
juvenile arthritis)
- Chronic inflammation of joints & side effects of long-term high-dose glucocorticoid therapy
- short stature d/2 Stiffening, deformation of joints & growth retardation
Genetic causes of short stature
Turner syndrome
Down syndrome
Skeletal dysplasias
1)achondroplasia,
-most common skeletal dysplasia
-mutatition of fibroblast growth factor receptor 3 gene (FGFR3) → inhibited chondrocyte proliferation → reduced endochondral ossification →reduces longitudinal growth
-sx: short stature w/ short fat limbs, macrocephaly, normal intelligence
Rx: GH therapy, surgery got spinal deformities
2)osteogenesis imperfecta/ brittle bone
-autoDom mutation of COL1A1 or COL1A2 genes causing defective type I collagen synthesis → impaired bone matrix formation (osteogenesis)
-sx:
Growth retardation
Skeletal deformities, brittle bones, and recurrent fractures from minimal trauma
Blue sclerae
Progressive hearing loss
Brittle, opalescent teeth
Rx:
No cure
IV bisphosphonates to increase cortical thickness
How do neoplasms cause short stature
Nausea, and vomiting causes loss of electrolytes and malnourishment by cancer and chemotherapy and radiotherapy
Mass effect of hypothalamic or pituitary tumors → GH deficiency
Damage from radiation therapy:
Hypothalamus or pituitary glands → GH deficiency
Thyroid gland → primary hypothyroidism, reduced metabolism and Growth deficit due to poor appetite
Psychological/ psychosocial causes of short stature
- Childhood neglect/deprivation and abuse
- Anorexia nervosa, depression
Signs of neglect: poor growth or weight gain, poor hygiene, poor record of school attendance and medical care, abnormal parent–child interaction
Behavioral changes: e.g., apathy, anxiety, inattentiveness, aggression
Dg methods to determine short stature
Family history- for no path causes
LAB
- CBC,ESR,
- thyroid tests
- Renal function tests and urinalysis
- Screening GH deficiency IGF-1
- assess puberty status (LH, FSH, estrogen/testosterone)
- Genetic karyotyping: turner, downs etc
Imaging
-X-ray: A/P image of left hand and wrist for bone age. adult height is predicted by comparing x-ray images of the hand to images of bones in a standard atlas of bone development based on data from large numbers of other children of the same age and gender.
Rx of short stature
depends on the underlying cause:
-Reassurance that short stature is normal (familial, constitutional) in most cases
- Discontinue growth-inhibiting medication
- hormone substitution in children with delayed puberty and growth
- GH supplementation in cases of GH deficiency, idiopathic short stature, or Turner syndrome
- Levothyroxine supplementation in hypothyroidism
