Growth in a case of Russell-Silver syndrome treated for hypopituitarism.

The growth characteristics of Russell-Silver syndrome (RSS) include dwarfism of prenatal onset, moderate retardation of bone age and normal postnatal height velocity. We describe a case of hypopituitarism in a girl with typical RSS who suffered from a severe trauma at birth. Signs of hypopituitarism appeared during childhood. Before substitutive treatment, a short course of human growth hormone (hGH) induced a moderate rise in plasma IGF-I levels which was within the range observed in other pituitary dwarfs. Under replacement therapy, catch-up growth was similar to what is observed in other growth hormone deficient children. However, bone age matured much faster than chronological age. This observation appears to be a particular feature of RSS, possibly enhanced by hGH therapy. An improvement of adult height beyond the final height usually observed in RSS children without endocrine disturbances should therefore not be expected from hGH therapy. Growth hormone deficiency and RSS do not appear to be causally related. However, in each child with RSS, a particular attention should be given to a decreased height velocity, a severely delayed bone age as well as a history of major perinatal problems. Should one of these factors be found, a careful evaluation of the hypothalamo-pituitary axis ought to be performed with, accordingly, an appropriate substitutive therapy.