Background: The association of NF1 with optic pathway glioma (OPT) and GH hypersecretion was initially described in some isolated cases, while the presence of PP was more frequently reported in these patients. Association of gigantism and precocious puberty (PP) in five children with OPT (isolated in two and associated with NF1 in three cases) has been recently published.
Aims: To evaluate the frequency of GH hypersecretion in children with NF1 and OPT, to verify the association of gigantism and PP in these patients, to find a possible correlation of GH hypersecretion and the MRI patterns of OPT.
Methods: We selected all patients with NF1 and OPT followed in our hospital. All of them underwent auxological evaluation. Children with clinical signs of gigantism (height >2 S.D. and/or growth velocity >2 S.D.) were submitted to biochemical study, including IGF1, IGFBP3, FT4, TSH, PRL, OGTT for glucose, insulin and GH levels, and bone age. Children with clinical signs of PP underwent GnRH test for LH and FSH and testosterone/estradiol levels, bone age, pelvic ultrasound in girls. MRI patterns of gliomas was reassessed by the same neuroradiologist.
Results: Sixty one patients with NF1 and OPT (35 boys, age 2.117.9 years) were included in the study. Seven out of 61 (11.5%) presented clinical signs of gigantism. All of them showed IGF1 and IGFBP3 levels >2 S.D. and lack of GH levels suppression after OGTT was demonstrated in four cases. PP was confirmed in four children, isolated in three cases and associated with gigantism in one boy. MRI in all children with gigantism showed extension of OPT at least to pre-chiasmal region.
Conclusion: GH hypersecretion is often associated with OPT in NF1 children and it is more frequent than PP. There is evident correlation between extention of glioma and presence of GH hypersecretion.
01 - 03 Oct 2015
European Society for Paediatric Endocrinology