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Pediatric Radiology

, Volume 43, Issue 9, pp 1190–1195 | Cite as

Temporal and occipital lobe features in children with hypochondroplasia/FGFR3 gene mutation

  • Cristina M. PhilpottEmail author
  • Elysa Widjaja
  • Charles Raybaud
  • Helen M. Branson
  • Peter Kannu
  • Susan Blaser
Original Article

Abstract

Background

Thanatophoric dysplasia (TD) and hypochondroplasia are both caused by FGFR3 (fibroblast growth factor receptor 3) gene mutations. Temporal lobe dysplasia has been well described in thanatophoric dysplasia; however, only a couple of anecdotal cases of temporal lobe dysplasia in hypochondroplasia have been described.

Objective

To define temporal lobe abnormalities in patients with hypochondroplasia, given that they share the same genetic mutation.

Materials and methods

We identified brain imaging studies of nine children with hypochondroplasia. The temporal lobes were assessed on CT and MRI for size and configuration of the temporal horn and aberrant sulcation of the inferior surface of the temporal lobe.

Results

All children had a triangular-shape temporal horn and deep transverse fissures of the inferior temporal lobe surface. Neuroimaging in our cohort revealed enlarged temporal lobes and oversulcation of the mesial temporal and occipital lobes, with abnormal inferomedial orientation of these redundant gyri. Hippocampal dysplasia was also universal.

Conclusion

We confirmed frequent inferomesial temporal and occipital lobe abnormalities in our cohort of children with hypochondroplasia. Murine models with mutant fgfr3 display increased neuroprogenitor proliferation, cortical thickness and surface area in the temporo-occipital cortex. This is thought to result in excessive convolution and likely explains the imaging findings in this patient cohort. (Note that fgfr3 is the same genetic mutation in mice as FGFR3 is in humans.)

Keywords

FGFR3 gene mutation Hypochondroplasia Mesial temporal lobe Hippocampal dysplasia MRI Children 

Notes

Conflicts of interest

None

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Copyright information

© Springer-Verlag Berlin Heidelberg 2013

Authors and Affiliations

  • Cristina M. Philpott
    • 1
    Email author
  • Elysa Widjaja
    • 2
  • Charles Raybaud
    • 2
  • Helen M. Branson
    • 2
  • Peter Kannu
    • 3
  • Susan Blaser
    • 2
  1. 1.Department of NeuroradiologyThe Hospital for Sick ChildrenTorontoCanada
  2. 2.Diagnostic ImagingThe Hospital for Sick ChildrenTorontoCanada
  3. 3.Division of Clinical and Metabolic GeneticsThe Hospital for Sick ChildrenTorontoCanada

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