Patients (aged 4.0-15.1 years) had proportionate short stature (height −2.8 ± 0.5 SDS), failure to thrive with low appetite (n = 4), a mean serum insulin-like growth factor-I (IGF-I) of −1.6 ± 0.7 SDS, and a normal stimulated GH response. The gene discussed is IGF1; the disease is Failure to thrive.