Classification and Follow-up of Children Referred for Growth Failure
Elizabeth Fudge, MD
Background and Significance
The availability of biosynthetic growth hormone (GH) since 1985 has resulted in a market driven, rather than evidence-based relaxation of the diagnostic criteria for GH deficiency which requires GH replacement therapy, and expansion to treatment of non-GH deficient short children. This development has been referred to as expansive biotechnology, where treatment of conditions for which the conceptual boundary between disease and variation, and therefore, between treatment and enhancement, is blurred. This marketing method, identification of non-disease as a treatable condition, has been termed “disease mongering”.
Most children seen in the growth clinic will have constitutional delay of growth and maturation (CDGM) with expected normal adult stature or familial short stature (FSS) with height expectation appropriate for genetic endowment. A small percentage will have idiopathic short stature (ISS) and a very small percentage of this last group will be found to have genetic mutations in the growth hormone-insulin like growth factor pathway. The FDA approval for treatment of ISS recently has met with considerable controversy, because the definition provided for the indication could include children with CDGM or FSS, the studies on which the approval was based are faulty, and there is no evidence that the modest, at best, height improvement attained is of benefit.
Hypothesis and Rationale
The hypotheses to be pursued in this study are that proper classification of children referred for short stature who do not have an endocrine disorder, or are not chronically ill or syndromic will yield no more than 10% with idiopathic short stature and that nonintervention will be justified by acceptable growth velocity over the 12 to 24 months following referral.
- Identify ~600 patients referred for growth failure before one year preceding the start of the study.
- Applying specific criteria, classify referrals as GH deficient, FSS, CDGM, CDGM + FSS, ISS, or syndromic (Turner, Silver-Russell, etc.).
- Determine growth velocity and associated parameters during follow-up evaluations.