Loss of CHSY1, a secreted FRINGE enzyme, causes syndromic brachydactyly in humans via increased NOTCH signaling

Jing Tian, Ling Ling, Mohammad Shboul, Hane Lee, Brian O'Connor, Barry Merriman, Stanley F. Nelson, Simon Cool, Osama H. Ababneh, Azmy Al-Hadidy, Amira Masri, Hanan Hamamy, Bruno Reversade

Research output: Contribution to journalArticlepeer-review

77 Scopus citations


We delineated a syndromic recessive preaxial brachydactyly with partial duplication of proximal phalanges to 16.8 Mb over 4 chromosomes. High-throughput sequencing of all 177 candidate genes detected a truncating frameshift mutation in the gene CHSY1 encoding a chondroitin synthase with a Fringe domain. CHSY1 was secreted from patients' fibroblasts and was required for synthesis of chondroitin sulfate moieties. Noticeably, its absence triggered massive production of JAG1 and subsequent NOTCH activation, which could only be reversed with a wild-type but not a Fringe catalytically dead CHSY1 construct. In vitro, depletion of CHSY1 by RNAi knockdown resulted in enhanced osteogenesis in fetal osteoblasts and remarkable upregulation of JAG2 in glioblastoma cells. In vivo, chsy1 knockdown in zebrafish embryos partially phenocopied the human disorder; it increased NOTCH output and impaired skeletal, pectoral-fin, and retinal development. We conclude that CHSY1 is a secreted FRINGE enzyme required for adjustment of NOTCH signaling throughout human and fish embryogenesis and particularly during limb patterning. © 2010 by The American Society of Human Genetics. All rights reserved.
Original languageEnglish (US)
Pages (from-to)768-778
Number of pages11
JournalAmerican Journal of Human Genetics
Issue number6
StatePublished - Dec 10 2010
Externally publishedYes

Bibliographical note

Generated from Scopus record by KAUST IRTS on 2023-02-15

ASJC Scopus subject areas

  • Genetics
  • Genetics(clinical)


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