1. Academic Validation
  2. TTC21B contributes both causal and modifying alleles across the ciliopathy spectrum

TTC21B contributes both causal and modifying alleles across the ciliopathy spectrum

  • Nat Genet. 2011 Mar;43(3):189-96. doi: 10.1038/ng.756.
Erica E Davis 1 Qi Zhang Qin Liu Bill H Diplas Lisa M Davey Jane Hartley Corinne Stoetzel Katarzyna Szymanska Gokul Ramaswami Clare V Logan Donna M Muzny Alice C Young David A Wheeler Pedro Cruz Margaret Morgan Lora R Lewis Praveen Cherukuri Baishali Maskeri Nancy F Hansen James C Mullikin Robert W Blakesley Gerard G Bouffard NISC Comparative Sequencing Program Gabor Gyapay Susanne Rieger Burkhard Tönshoff Ilse Kern Neveen A Soliman Thomas J Neuhaus Kathryn J Swoboda Hulya Kayserili Tomas E Gallagher Richard A Lewis Carsten Bergmann Edgar A Otto Sophie Saunier Peter J Scambler Philip L Beales Joseph G Gleeson Eamonn R Maher Tania Attié-Bitach Hélène Dollfus Colin A Johnson Eric D Green Richard A Gibbs Friedhelm Hildebrandt Eric A Pierce Nicholas Katsanis
Affiliations

Affiliation

  • 1 Center for Human Disease Modeling, Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, USA.
Abstract

Ciliary dysfunction leads to a broad range of overlapping phenotypes, collectively termed ciliopathies. This grouping is underscored by genetic overlap, where causal genes can also contribute modifier alleles to clinically distinct disorders. Here we show that mutations in TTC21B, which encodes the retrograde intraflagellar transport protein IFT139, cause both isolated nephronophthisis and syndromic Jeune asphyxiating thoracic dystrophy. Moreover, although resequencing of TTC21B in a large, clinically diverse ciliopathy cohort and matched controls showed a similar frequency of rare changes, in vivo and in vitro evaluations showed a significant enrichment of pathogenic alleles in cases (P < 0.003), suggesting that TTC21B contributes pathogenic alleles to ∼5% of ciliopathy cases. Our data illustrate how genetic lesions can be both causally associated with diverse ciliopathies and interact in trans with other disease-causing genes and highlight how saturated resequencing followed by functional analysis of all variants informs the genetic architecture of inherited disorders.

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