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
  • 1. Center for Human Disease Modeling, Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, USA.
PMID: 21258341 DOI: 10.1038/ng.756
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.