Mutational Spectrum in Holoprosencephaly Shows That FGF is a New Major Signaling Pathway

Hum Mutat. 2016 Dec;37(12):1329-1339. doi: 10.1002/humu.23038. Epub 2016 Aug 23.


Holoprosencephaly (HPE) is the most common congenital cerebral malformation in humans, characterized by impaired forebrain cleavage and midline facial anomalies. It presents a high heterogeneity, both in clinics and genetics. We have developed a novel targeted next-generation sequencing (NGS) assay and screened a cohort of 257 HPE patients. Mutations with high confidence in their deleterious effect were identified in approximately 24% of the cases and were held for diagnosis, whereas variants of uncertain significance were identified in 10% of cases. This study provides a new classification of genes that are involved in HPE. SHH, ZIC2, and SIX3 remain the top genes in term of frequency with GLI2, and are followed by FGF8 and FGFR1. The three minor HPE genes identified by our study are DLL1, DISP1, and SUFU. Here, we demonstrate that fibroblast growth factor signaling must now be considered a major pathway involved in HPE. Interestingly, several cases of double mutations were found and argue for a polygenic inheritance of HPE. Altogether, it supports that the implementation of NGS in HPE diagnosis is required to improve genetic counseling.

Keywords: FGF signaling pathway; brain malformation; holoprosencephaly; multigenic inheritance; targeted NGS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Female
  • Fibroblast Growth Factors / genetics*
  • Genetic Predisposition to Disease
  • Hedgehog Proteins / genetics
  • High-Throughput Nucleotide Sequencing / methods
  • Holoprosencephaly / genetics*
  • Humans
  • Male
  • Mutation*
  • Receptor, Fibroblast Growth Factor, Type 1
  • Sequence Analysis, DNA / methods
  • Signal Transduction


  • Hedgehog Proteins
  • SHH protein, human
  • Fibroblast Growth Factors
  • FGFR1 protein, human
  • Receptor, Fibroblast Growth Factor, Type 1