IGF-I and IGF Binding Protein-3 Generation Tests and Response to Growth Hormone in Children with Silver-Russell Syndrome

Russell Silver syndrome: a perspective on growth and the influence of growth hormone therapy

A 6 years male child was referred to our Endocrinology clinic with complaints of failure to thrive and he displayed the characteristic features of Russell Silver Syndrome which included short stature, relative macrocephaly, triangular facies and bilateral clinodactyly. He had a birth weight of 2.14 kg and an expected target height of 170 cm. He was subjected to a hormonal analysis which revealed a normal thyroid profile, but low serum markers of growth namely IGF-1=68 ng/ml (52-297 ng/ml) and basal growth hormone (GH) (1.5 μg/l). No defects were detected on MRI of the sella. Therefore a growth hormone stimulation test with Clonidine was performed which confirmed complete GH deficiency (at 0 min=0.16 μg/l, 60 min=0.27 μg/l, 120 min=4.73 μg/l). He was commenced on rhGH therapy at 8 years of age (height=102 cm, SDS=-4.53), due to financial restraints. Following initiation of GH therapy (1.5 IU/day) for 19 months, a height gain of 15 cm was obtained (Height=117 cm, SDS=-3.05). Bone age at 9 yr. was between 7-8 years.