Growth hormone deficiency in children with neurofibromatosis type 1 without suprasellar lesions

Risk factors for shortness of stature in children with neurofibromatosis type 1 (NF-1) include suprasellar lesions, which can lead to growth hormone deficiency (GHD), skeletal deformities, nutritional insufficiency, and methylphenidate use. At our Neurofibromatosis Clinic, we have observed short children growing poorly without these risk factors. This study investigated whether GHD occurs in children with NF-1 in the absence of suprasellar lesions. Of 251 children with NF-1, 112 were at or below the 25th percentile for height (68 were at or below the 10th). Of these, 51 children, 5-16 years of age were short, growing poorly, and without medical or radiologic findings to explain the poor growth. In 19 of 51, we evaluated GH secretion; 15 of 19 had GHD (peak GH level less than 5 ng/mL in most cases). These findings suggest that GHD may be relatively common in short children with NF-1 without suprasellar abnormalities, suggesting an association with NF-1 independent of organic, pituitary damage. Larger cohorts of NF-1 children should be evaluated to clarify whether NF-1 represents a novel etiology of GHD. Also, a careful assessment of GH secretion in children with NF-1 who are growing poorly in the absence of another clinical explanation is warranted.