Long-Term Results of GH Treatment in Silver-Russell Syndrome (SRS): Do They Benefit the Same as Non-SRS Short-SGA?

CONTEXT: Silver-Russell syndrome (SRS) is a genetically heterogeneous syndrome characterized by low birth weight, severe short stature, and variable dysmorphic features. GH treatment is a registered growth-promoting therapy for short children born small for gestational age, including SRS, but there are limited data on the GH response in SRS children and on differences in response among the (epi)genetic SRS subtypes (11p15 aberrations, maternal uniparental disomy of chromosome 7 [mUPD7], and idiopathic SRS).

OBJECTIVES: To compare growth and adult height between GH-treated small for gestational age children with and without SRS (non-SRS), and to analyze the difference in GH response among SRS genotypes.

DESIGN AND SETTING: A longitudinal study.

PARTICIPANTS: Sixty-two SRS and 227 non-SRS subjects.

INTERVENTION: All subjects received GH treatment (1 mg/m(2)/d).

MAIN OUTCOME MEASURES: Adult height and total height gain.

RESULTS: The SRS group consisted of 31 children with 11p15 aberrations, 11 children with mUPD7, and 20 children with idiopathic SRS. At the start of GH treatment, mean (SD) height standard deviation score [SDS] was significantly lower in SRS (-3.67 [1.0]) than in non-SRS (-2.92 [0.6]; P < .001). Adult height SDS was lower in SRS (-2.17 [0.8]) than in non-SRS (-1.65 [0.8]; P = .002), but the total height gain SDS was similar. There was a trend toward a greater height gain in mUPD7 than in 11p15 (P = .12).

CONCLUSION: Children with SRS have a similar height gain during GH treatment as non-SRS subjects. All (epi)genetic SRS subtypes benefit from GH treatment, with a trend toward mUPD7 and idiopathic SRS having the greatest height gain.