A site for medical students - Practical,Theory,Osce Notes

Dwarfism and its causes

Dwarfism is defined as marked permanent shortness of stature, with predicted adult height of the person less than 4 standard deviations from the mean. An adult may be called a dwarf, if his height is less than 4 feet.
What are the causes of short stature?
Normal variant of short stature
  • Familial short stature
  • Constitutional growth delay
  • Racial.
Pathological causes of short stature
Proportionate dwarfism
  • Prenatal
  • Intrauterine growth retardation 
  • Antenatal infection in mother (TORCH*,syphilis, AIDS)
  • Antenatal consumption of alcohol, tobacco, heroin
  • Chromosomal disorders (Down's syndrome, Turner's syndrome). 
  • Postnatal
  • Malnutrition ,Protein-energy malnutrition, anorexia nervosa
  • Endocrine disorder growth hormone deficiency, hypothyroidism, congenital adrenal hyperplasia, precocious puberty pseudohypoparathyroidism
  • Cardiovascular disorders of cyanotic and acyanotic congenital heart disease, early onset rheumatic heart disease.
  • Respiratory disorders Kartagener's syndrome, cystic lung disease, childhood asthma 
  • Renal disorders renal tubular acidosis, renal rickets, nephrotic syndrome, chronic' pyelonephritis
  • Blood disorders ,chronic anemia like thalassemia or sickle cell anemia leukemia
  • Psychosocial disorders (maternal deprivation)
Disproportionate dwarfism
  • Rickets 
  • Skeletal dysplasia (kyphosis, lordosis, scoliosis)
  • Defective bone formation (osteopetrosis, osteogenesis imperfecta)
  • Defective cartilage growth (achondroplasia multiple cartilagenous exostosis)
  • Defective bone matrix (fibrous dysplasia)
  • Inborn error of metabolism (mucopolysaccharidosis)
  • Calcium and phosphorus metabolism defects (hyperphosphatemic rickets)
  • Metabolic disease (Wilson's disease, zinc deficiency).
What are the common causes of shortstature?
  • Hereditory
  • Constitutiona; delay in growth
  • Protein energy malnutrition (this is the commonest cause of malnutrition in developing countries)
  • Rickets.
  • Cretinism.
  • Pituitary dwarf.
  • Achondroplasia: mucopolysaccharidosis
  • Congenital cyanotic heart diseases e.g. Fallot s tetralogy
  • Gross kyphoscoliosis
  • Down’s syndrome or Turner's syndrome.