Exome Analysis Reveals Novel Missense and Deletion Variants in the CC2D2A Gene as Causative of Joubert Syndrome

Genes (Basel). 2023 Mar 28;14(4):810. doi: 10.3390/genes14040810.


The CC2D2A gene is essential for primary cilia formation, and its disruption has been associated with Joubert Syndrome-9 (JBTS9), a ciliopathy with typical neurodevelopmental features. Here, we describe an Italian pediatric patient with typical features of Joubert Syndrome (JBTS): "Molar Tooth Sign", global developmental delay, nystagmus, mild hypotonia, and oculomotor apraxia. Whole exome sequencing and segregation analysis identified in our infant patient a novel heterozygous germline missense variant c.3626C > T; p.(Pro1209Leu) inherited from the father and a novel 7.16 kb deletion inherited from the mother. To the best of our knowledge, this is the first report showing a novel missense and deletion variant involving exon 30 of the CC2D2A gene.

Keywords: CC2D2A; Joubert Syndrome; compound heterozygous; deletion; missense; pediatric.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abnormalities, Multiple* / genetics
  • Cerebellum
  • Child
  • Cytoskeletal Proteins / genetics
  • Exome / genetics
  • Eye Abnormalities* / genetics
  • Humans
  • Infant
  • Kidney Diseases, Cystic* / genetics
  • Mutation
  • Retina


  • CC2D2A protein, human
  • Cytoskeletal Proteins

Supplementary concepts

  • Agenesis of Cerebellar Vermis

Grants and funding

This work was funded by the Italian Ministry of Health: Rete IDEA—Fondo progetti di Ricerca corrente Reti IRCCS RCR-2021-23671215 and RCR-2022-23682289.