Good response to long-term therapy with growth hormone in a patient with 9p trisomy syndrome: A case report and review of the literature.

The 9p trisomy syndrome is a rare condition, clinically characterized by a wide range of dysmorphic features, intellectual disability, and, in most patients, by short stature. Recombinant human growth hormone (rhGH) therapy is still controversial in syndromic disorders, the reason for which it is not currently indicated. Here we report a 7-year-old boy with 9p trisomy syndrome and marked short stature. Results of routine laboratory assessments were normal. IGF1 and IGFBP3 levels were both in the normal range (-1.6 and -0.7 SDS, respectively). GH peak in response to oral clonidine stimulation test was 3.5 μg/L, which is considered a normal response. Chromosomal analysis revealed the karyotype 47,XY, + del(9)(pter-q11:) dn. SNP array data indicated absence of mosaicism [arr 9p24.3-p13.1 (203,861-38,787,480) x3]. By the age of 8.3 years, the patient had persistent short stature (-2.9 SDS) with normal growth velocity (4.9 cm/y; -0.7 SDS), not showing spontaneous catch-up. After 5.6 years of rhGH therapy (50 μg/kg/d), height SDS improved from -2.9 to -1.0. This result suggests that rhGH therapy could be considered for patients with 9p trisomy syndrome who present with short stature. The degree of intellectual disability and the potential for social inclusion should be taken into account when recommending this treatment. Additional studies are needed to establish the benefits of height gain in these patients.