Tetratricopeptide repeat protein 21B
The TTC21 gene encodes a ciliary protein that is responsible for retrograde intraflagellar transport. Mutations cause various recessive ciliopathies such as Joubert syndrome 11, and Nephronophthisis 12.
Tran PV et. al. (2008) THM1 negatively modulates mouse sonic hedgehog signal transduction and affects retrograde intraflagellar transport in cilia.
Davis EE et. al. (2011) TTC21B contributes both causal and modifying alleles across the ciliopathy spectrum.
Update: Sept. 26, 2018