Iqcb1, also known as NPHP5, is a gene encoding the ciliary protein nephrocystin 5. It is crucial for ciliary function, especially in photoreceptor outer segment formation [4,8]. The protein is involved in ciliopathy-related pathways and plays a significant role in maintaining normal retinal and kidney functions [2,3,5,6,7,8]. Gene knockout models, such as the Nphp5-knockout mice, have been instrumental in studying its function [8].

In human studies, elevated Iqcb1 expression is associated with a poorer prognosis in liver hepatocellular carcinoma patients, indicating its potential as a diagnostic and prognostic molecular marker. It also shows correlations with MKI67, HBV, HCV, and AFP, and is related to immune infiltration and checkpoint mechanisms [1]. In retinopathy, Iqcb1-related diseases present as severe early-onset cone-rod dystrophies. Patients with Iqcb1 mutations may have either syndromic (with renal failure) or non-syndromic retinopathy [2,3,5,7].

In conclusion, Iqcb1 is essential for ciliary-related functions in the retina and kidneys. The use of gene knockout mouse models has helped to reveal its role in photoreceptor outer segment formation. In human diseases, it is implicated in liver cancer prognosis and various retinopathy conditions, highlighting its importance in understanding disease mechanisms and potentially developing new treatments.

References:

1. Han, Dongmei, Ling, Bin, Wu, Caihong, Jin, Hao. 2024. The role of IQCB1 in liver cancer: a bioinformatics analysis. In Translational cancer research, 13, 5021-5036. doi:10.21037/tcr-24-110. https://pubmed.ncbi.nlm.nih.gov/39430824/

2. Sen, Sagnik, Fabozzi, Lorenzo, Fujinami, Kaoru, Georgiou, Michalis, Michaelides, Michel. 2024. IQCB1 (NPHP5)-Retinopathy: Clinical and Genetic Characterization and Natural History. In American journal of ophthalmology, 264, 205-215. doi:10.1016/j.ajo.2024.03.009. https://pubmed.ncbi.nlm.nih.gov/38522724/

3. Wang, Junwen, Li, Shiqiang, Jiang, Yi, Wang, Panfeng, Zhang, Qingjiong. 2023. Pathogenic Variants in CEP290 or IQCB1 Cause Earlier-Onset Retinopathy in Senior-Loken Syndrome Compared to Those in INVS, NPHP3, or NPHP4. In American journal of ophthalmology, 252, 188-204. doi:10.1016/j.ajo.2023.03.025. https://pubmed.ncbi.nlm.nih.gov/36990420/

4. Yu, Tiffany, Matsuda, Miho. 2020. Epb41l5 interacts with Iqcb1 and regulates ciliary function in zebrafish embryos. In Journal of cell science, 133, . doi:10.1242/jcs.240648. https://pubmed.ncbi.nlm.nih.gov/32501287/

5. Estrada-Cuzcano, Alejandro, Koenekoop, Robert K, Coppieters, Frauke, Cremers, Frans P M, den Hollander, Anneke I. 2011. IQCB1 mutations in patients with leber congenital amaurosis. In Investigative ophthalmology & visual science, 52, 834-9. doi:10.1167/iovs.10-5221. https://pubmed.ncbi.nlm.nih.gov/20881296/

6. Kruczek, Kamil, Qu, Zepeng, Welby, Emily, Brooks, Brian P, Swaroop, Anand. 2022. In vitro modeling and rescue of ciliopathy associated with IQCB1/NPHP5 mutations using patient-derived cells. In Stem cell reports, 17, 2172-2186. doi:10.1016/j.stemcr.2022.08.006. https://pubmed.ncbi.nlm.nih.gov/36084637/

7. Vincent, A, AlAli, A, MacDonald, H, VandenHoven, C, Héon, E. 2017. Specific retinal phenotype in early IQCB1-related disease. In Eye (London, England), 32, 646-651. doi:10.1038/eye.2017.283. https://pubmed.ncbi.nlm.nih.gov/29219953/

8. Ronquillo, Cecinio C, Hanke-Gogokhia, Christin, Revelo, Monica P, Jiang, Li, Baehr, Wolfgang. 2016. Ciliopathy-associated IQCB1/NPHP5 protein is required for mouse photoreceptor outer segment formation. In FASEB journal : official publication of the Federation of American Societies for Experimental Biology, 30, 3400-3412. doi:. https://pubmed.ncbi.nlm.nih.gov/27328943/