The WDR19 gene (also known as IFT144) provides instructions for making a protein that is involved in the formation and maintenance of cilia, which are microscopic, finger-like projections that stick out from the surface of cells. Cilia participate in signaling pathways that transmit information within and between cells and are important for the development and function of many types of cells and tissues, including cells in the kidneys and liver and the light-sensitive tissue at the back of the eye (the retina). Cilia also play a role in the development of the bones, although the mechanism is not well understood.
The movement of substances within cilia and similar structures called flagella is known as intraflagellar transport. This process is essential for the assembly and maintenance of these cell structures. During intraflagellar transport, cells use molecules called IFT particles to carry materials to and from the tips of cilia. Each IFT particle is made up of two groups of IFT proteins: complex A and complex B. The protein produced from the WDR19 gene forms part of IFT complex A (IFT-A). During intraflagellar transport, this complex carries materials from the tip to the base of cilia.
The IFT-A complex is essential for proper regulation of the Sonic Hedgehog signaling pathway, which is important for the growth and maturation (differentiation) of cells and the normal shaping (patterning) of many parts of the body, especially during embryonic development. The exact role of the complex in this pathway is unclear.
Health Conditions Related to Genetic Changes
At least two mutations in the WDR19 gene have been found in individuals with cranioectodermal dysplasia. This condition is characterized by an elongated head (dolichocephaly) with a prominent forehead and other distinctive facial features; short bones; and abnormalities of certain tissues known as ectodermal tissues, which include the teeth, hair, nails, and skin. Cranioectodermal dysplasia can also cause a variety of other problems, including a kidney condition called nephronophthisis and eye abnormalities.
The WDR19 gene mutations involved in cranioectodermal dysplasia reduce the amount of functional WDR19 protein. A shortage or reduction in activity of this component of the IFT-A complex impairs the function of the entire complex, disrupting transport of proteins and materials from the tips of cilia. As a result, assembly and maintenance of cilia is impaired, which leads to a smaller number of cilia and abnormalities in their shape and structure. Although the mechanism is unclear, a loss of normal cilia impedes proper development of bone and other tissues, leading to the features of cranioectodermal dysplasia. Some researchers suggest that disrupted intraflagellar transport prevents signaling through the Sonic Hedgehog pathway, which could impact cell growth and other functions in several tissues throughout the body.More About This Health Condition
Asphyxiating thoracic dystrophy
MedlinePlus Genetics provides information about Asphyxiating thoracic dystrophyMore About This Health Condition
MedlinePlus Genetics provides information about NephronophthisisMore About This Health Condition
MedlinePlus Genetics provides information about Retinitis pigmentosaMore About This Health Condition
MedlinePlus Genetics provides information about Senior-Løken syndromeMore About This Health Condition
Other Names for This Gene
- intraflagellar transport 144 homolog
Additional Information & Resources
Tests Listed in the Genetic Testing Registry
Scientific Articles on PubMed
Catalog of Genes and Diseases from OMIM
- Bredrup C, Saunier S, Oud MM, Fiskerstrand T, Hoischen A, Brackman D, Leh SM, Midtbo M, Filhol E, Bole-Feysot C, Nitschke P, Gilissen C, Haugen OH, Sanders JS, Stolte-Dijkstra I, Mans DA, Steenbergen EJ, Hamel BC, Matignon M, Pfundt R, Jeanpierre C, Boman H, Rodahl E, Veltman JA, Knappskog PM, Knoers NV, Roepman R, Arts HH. Ciliopathies with skeletal anomalies and renal insufficiency due to mutations in the IFT-A gene WDR19. Am J Hum Genet. 2011 Nov 11;89(5):634-43. doi: 10.1016/j.ajhg.2011.10.001. Epub 2011 Oct 20. Citation on PubMed or Free article on PubMed Central
- Coussa RG, Otto EA, Gee HY, Arthurs P, Ren H, Lopez I, Keser V, Fu Q, Faingold R, Khan A, Schwartzentruber J, Majewski J, Hildebrandt F, Koenekoop RK. WDR19: an ancient, retrograde, intraflagellar ciliary protein is mutated in autosomal recessive retinitis pigmentosa and in Senior-Loken syndrome. Clin Genet. 2013 Aug;84(2):150-9. doi: 10.1111/cge.12196. Citation on PubMed or Free article on PubMed Central
- Liem KF Jr, Ashe A, He M, Satir P, Moran J, Beier D, Wicking C, Anderson KV. The IFT-A complex regulates Shh signaling through cilia structure and membrane protein trafficking. J Cell Biol. 2012 Jun 11;197(6):789-800. doi: 10.1083/jcb.201110049. Citation on PubMed or Free article on PubMed Central
- Tan W, Lin A, Keppler-Noreuil K. Cranioectodermal Dysplasia. 2013 Sep 12 [updated 2022 Dec 15]. In: Adam MP, Feldman J, Mirzaa GM, Pagon RA, Wallace SE, Bean LJH, Gripp KW, Amemiya A, editors. GeneReviews(R) [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2024. Available from http://www.ncbi.nlm.nih.gov/books/NBK154653/ Citation on PubMed