Validity of height velocity as a diagnostic criterion for idiopathic growth hormone deficiency and Turner syndrome

A deflecting growth curve over several years is sometimes the only indicati on for the possible presence of a growth disorder. In this study we looked at the potential diagnostic role of long-term downward deflection of the gr owth curve;lt reports on the diagnostic validity of height velocity over 1, 2 or 3 years for isolated idiopathic growth hormone deficiency and for Tur ner syndrome in prepubertal children with a height that is still above -2.5 standard deviation scores (SDS), 1-year height velocity was found to have no diagnostic value because of an almost complete overlap of height velocit y distributions with normal prepubertal children. However,height velocity o ver 3 years was found to have an acceptable validity in children 5-12 years old. In this age range a change in height SDS of -0.75 can be used as a va lid criterion for further examination of karyotype and GH secretion capacit y even if there are no other clear signs of a particular growth disorder.