Before a parent becomes concerned about the failure of a child to grow in height or weight, they should look at themselves. If both parents are small, it is unlikely that the child is going to reach average height. Genetics play a vital part in development and growth, and many of the causes of abnormally reduced growth are caused by a defect in the individual’s genes.
A child that is deprived of adequate nutrition will obviously not reach his or her expected height or weight, and anyone who suffers from a long-term illness will have his or her growth affected. Conditions as varied as severe asthma, underactive thyroid gland, heart disease (e.g. hole in the heart), kidney infections or failure, coeliac disease (inability to digest gluten in wheat), other conditions in which food is poorly absorbed, deficiencies of vitamins or minerals (particularly zinc), Crohn disease (thickening and ulceration of a segment of gut) and cystic fibrosis (thick mucus in lungs and gut) are examples.
Steroid drugs may be used to control some long-term diseases, but can affect growth as a side-effect.
Psychiatric conditions such as anorexia nervosa may severely affect the nutrition of teenagers (particularly girls) and prevent them from ever reaching their expected height or weight.
The pituitary gland in the centre of the brain controls every other gland (eg. thyroid, ovary, testes) in the body. If this becomes diseased or damaged by a tumour it will have generalised adverse effects including altered growth rates.
Precocious puberty is the term for a very early development of adult sexual characteristics. Growth may cease early when this occurs, resulting in the individual being shorter than expected.
Foetal alcohol syndrome is caused by the mother drinking excessive amounts of alcohol during pregnancy, and results in a small baby that grows very slowly in the first few years of life. Small amounts of social drinking, and even the occasional episode of drunkenness during pregnancy do NOT cause this problem (although they are not advisable).
A large number of rare syndromes that affect the individual’s genetic make-up, bodily functions and general health can affect growth and result in dwarfism. A few of these include:-
- Bassen-Kornzweig syndrome (poor food absorption, poor coordination)
- Cockayne syndrome (blind and deaf)
- de Lange syndrome (intellectual disability, small head, hairy skin)
- Down syndrome (broad face, intellectual disability, slanted eyes)
- Hurler syndrome (abnormal facial development, inflamed joints)
- Laron dwarfism (due to lack of somatomedin C)
- Noonan syndrome (wide neck, prominent chest)
- Turner syndrome (female who fails to develop sexually due to a genetic defect)
- Von Gierke syndrome (low blood sugar, persistent diarrhoea)
- Russell-Silver syndrome (uneven size of body sides)