A novel splice site mutation in the SDCCAG8 gene in an Iranian family with Bardet–Biedl syndrome



Bardet–Biedl syndrome (BBS: OMIM 209,900) is a rare ciliopathic human genetic disorder that affects many parts of the body systems. BBS is a genetically heterogeneous disorder with a wide spectrum of clinical manifestations which makes its diagnosis and management more challenging. RetNet reports 18 genes that cause BBS and each of genes has had several known mutations. Genetic studies suggesting that serologically defined colon cancer antigen 8 (SDCCAG8) gene mutations are a major cause of BBS.

Materials and methods

In this section, we investigated the consanguineous Iranian family members with BBS. Whole-exome sequencing and Sanger sequencing, were performed to screen and confirm the suspicious pathogenic mutations. The identified mutation was investigated using bioinformatics tools to predict the effect of the mutation on protein structure.


Sequential analysis identified a novel splice site mutation c.1221 + 2 T > A in the SDCCAG8 gene in BBS patients. Structure-based approaches have predicted significant structural alterations in SDCCAG8 protein.


This study was conducted to show the aberrant alternative splicing as one of the single splicing mutations identified can cause BBS by affecting the function of SDCCAG8 protein.

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Bardet–Biedl syndrome


Serologically defined colon cancer antigen 8


Whole-exome sequencing


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This study has been granted by the University of Medical Sciences, Tabriz, Iran (Grant Number: 64764). We would like to thank the University of Medical Sciences Semnan, Iran for their collaboration and support. Moreover, we would like to express our sincere thanks to the family members who participated in this study, and we profoundly appreciate their collaboration in making this study possible.

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Correspondence to Hossein Darvish or Babak Emamalizadeh.

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Bahmanpour, Z., Daneshmandpour, Y., Kazeminasab, S. et al. A novel splice site mutation in the SDCCAG8 gene in an Iranian family with Bardet–Biedl syndrome. Int Ophthalmol 41, 389–397 (2021). https://doi.org/10.1007/s10792-020-01588-x

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  • Bardet–Biedl syndrome (BBS)
  • SDCCAG8 gene
  • Whole-exome sequencing
  • Novel mutation
  • bioinformatics