Neurological ciliopathies

Gene: CCDC28B

Red List (low evidence)

Not associated with a Joubert syndrome phenotype in OMIM, Gen2Phen or MONDO. PMID: 32139166 reports one homozygous CCDC28B variant (rs1407134) in a child with features of Joubert syndrome - polydactyly, severe intellectual disability and molar tooth sign in brain imaging. The fetal sibbling of this child (terminated) was also homozygous for this variant. The allele frequency of rs1407134 (gnomAD Exomes (V 2.1.1) ƒ = 0.0326) makes it unlikely to be disease causing, plus, it is classified as Benign in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/1271446/)
PMID: 23727834 demonstrates that CCDC28B is involved in the control of cilial length.

Created: 18 Apr 2023, 5:23 p.m. | Last Modified: 18 Apr 2023, 5:25 p.m.

Panel Version: 3.10

I don't know

Note new publication relating to this gene, which has previously been postulated to be a modifier for BBS. PMID: 32139166 - Single family with Joubert syndrome. Patient was homozygous for a missense, with polydactyly, severe ID, and the molar tooth sign observed in MRI. Sibling fetus MRI showed vermis hypoplasia, and was also homozygous for the variant. Parents confirmed unaffected carriers.

Borderline Amber/Red but note knockdown of CCDC28B in human TERT retinal pigment epithelial cells reduced both the number and length of cilia, providing some supportive evidence.
Sources: Expert list

Created: 21 May 2020, 4:34 a.m.

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Phenotypes
Joubert syndrome

Publications

• 32139166