Syndromes associated with growth deficiency.

There are literally hundreds of syndromes associated with short stature which have different prognoses, complications and responses to treatment (1 -3). A specific diagnosis is essential for accurate prognosis, treatment and genetic counselling. The first step in the clinical evaluation of short stature is to determine whether the body habitus is proportionate or disproportionate (Fig. 1). In general, children with disproportionate short stature have a skeletal dysplasia, whereas those with proportionate short stature usually have a more generalized disorder, such as intrauterine growth retardation (IUGR), malnutrition, chronic disease, psychosocial dwarfism, chromosomal anomalies or an endocrine disorder. Exceptions to this rule d o occur, however, such as the disproportionate dwarfism in severe cretinism or the proportionate shortening in osteogenesis imperfecta. A mildly disproportionate body habitus may not be apparent on casual examination, and thus anthropometric measurements, such as sitting height or upper/lower segment ratio and arm span, must be made before a relatively mild skeletal dysplasia, such as hypochondroplasia, can be excluded. Once a person with short stature is found to be proportionate, it is helpful to determine whether growth deficiency was of prenatal or postnatal onset. Prenatal onset growth deficiency usually implicates a fetal environmental insult or general cellular genetic defect. Late fetal insults are more likely to result in catch-up growth postnatally than prolonged