Dual activating FGFR1 mutations in pediatric pilomyxoid astrocytoma

Fibroblast growth factor receptor 1 gene mutation as a potential risk factor for spontaneous intracranial hemorrhage in pediatric low-grade glioma patients

Background

Fibroblast growth factor receptor 1 (FGFR1) mutations have been associated with poorer prognoses in pediatric central nervous system tumor patients. A recent study highlighted a link between FGFR1 mutations and spontaneous intracranial hemorrhage (ICH), demonstrating that all patients with an FGFR1 alteration experienced hemorrhage at some point during their course of treatment.

Methods

The current study examined 50 out of 67 pediatric patients with low-grade gliomas (LGGs) who had genomic testing between 2011 and 2022 at our institution to determine whether a correlation exists between FGFR1 mutations and spontaneous ICH.

Results

We found that of the 50 patients with genomic data, 7 (14%) experienced ICH, and an additional spontaneous hemorrhage was recorded; however, no genomic testing was performed for this case. Five of the seven patients (71.4%) had an FGFR1 modification. In our patient population, 6 expressed a detectable FGFR1 mutation (66.7% [4/6] had N546K alteration, 16.7% [1/6] FGFR1 exons duplication, and 16.7% [1/6] had a variant of unknown significance [VUS]). The patient with the FGFR1 VUS had no reported spontaneous hemorrhage. Statistical analysis found a significant association between FGFR1 and spontaneous intracranial hemorrhage (P-value = < .0001). In the patient population, all cases of PTPN11 alterations (n = 3) co-occurred with FGFR1 mutations.

Conclusions

Our case series highlights this link between the FGFR1 mutation and spontaneous intracranial hemorrhage in pediatric LGGs.