IFT172 is the largest component of the intraflagellar transport (IFT)-B complex required for primary cilia formation and maintenance 1. It facilitates bidirectional protein trafficking along cilia, essential for ciliary assembly and function 2. IFT172 plays an indirect role in hedgehog signaling, as cilia are required for all hedgehog pathway activity. Mutations in IFT172 cause diverse ciliopathies with variable severity. IFT172 deficiency leads to photoreceptor outer-segment protein mislocalization and rapid retinal degeneration, with complete photoreceptor loss within two months 2. The gene is associated with Bardet-Biedl syndrome 20, retinitis pigmentosa 71, and short-rib thoracic dysplasia 10 3. Recent evidence reveals IFT172 variants cause non-syndromic cholestatic liver disease 4 and autism-like behavioral phenotypes in mice 1. IFT172 haploinsufficiency impairs BDNF-TrkB signaling through transcription factor Gli3, reducing parvalbumin-expressing neurons and synaptic density 1. Additionally, IFT172 mutations may contribute to basal cell carcinoma development by disrupting ciliary-dependent hedgehog signaling 5. The gene's role extends beyond classical ciliopathies to neurodevelopmental and hepatobiliary disorders, expanding the clinical phenotypic spectrum of IFT172 mutations.