Ophthalmological ciliopathies

Gene: POC1B

Amber List (moderate evidence)

POC1B (POC1 centriolar protein B)
EnsemblGeneIds (GRCh38): ENSG00000139323
EnsemblGeneIds (GRCh37): ENSG00000139323
OMIM: 614784, Gene2Phenotype
POC1B is in 8 panels

4 reviews

Eleanor Williams (Genomics England Curator)

Amber rating confirmed with the Genomics England rare disease clinical team. This appears to be a single organ presentation of a disorder affecting cilia. It is appropriately green on the retinal disorders panel.
Created: 27 Jun 2019, 10:56 a.m. | Last Modified: 27 Jun 2019, 10:58 a.m.
Panel Version: 1.115
Comment on list classification: Multiple cases of a single feature (retinal dystrophy) disease, only one case plus disease model for multisystem ciliopathy. Rating Amber.
Created: 20 Jun 2019, 10:23 p.m. | Last Modified: 20 Jun 2019, 10:23 p.m.
Panel Version: 1.112
Associated with Cone-rod dystrophy 20 (615973) in OMIM and AUTOSOMAL-RECESSIVE CONE-ROD DYSTROPHY in Gene2Phenotype (confirmed).

PMID: 25044745 - Beck et al 2014 - consanguineous Iraqi family with Leber congenital amaurosis (LCA), Joubert syndrome (JBTS), and polycystic kidney disease (PKD). Whole-exome sequencing identified a homozygous missense variant, c.317G>C (p.Arg106Pro), in POC1B, a gene essential for ciliogenesis, basal body, and centrosome integrity. Both parents were heterozygous for the variant. The mutation affects an evolutionarily highly conserved residue of POC1B, and is expected to perturb the structure of the top face of the protein, to destabilize the protein and to compromise protein-protein interactions. POC1B localised to the basal body and centriole adjacent to the connecting cilium of photoreceptors and in synapses of the outer plexiform layer in human and mouse retina. Knockdown of Poc1b in zebrafish caused cystic kidneys and retinal degeneration with shortened and reduced photoreceptor connecting cilia, compatible with the human syndromic ciliopathy. The same variant was found by Durlu et al 2014 and in 1 family by Noosing et al 2014 but in both cases only eyes were affected.

PMID: 24945461 - Durlu et al 2014 - large consanguineous family (ethnicity not stated) with 4 individuals with Cone-rod dystrophy (CORD) only. POC1B c.317G>C (p.R106P) was found to segregate with the condition in the family. The affected individuals also shared a novel homozygous deletion at the disease locus but this was found to contain no genes and no evidence indicative of a gene regulatory function.

PMID: 25018096 - Roosing et al 2014 - 2 cases - a nonconsanguineous Turkish family (family A) with three siblings affected by cone dystrophy(COD) and cone-rod dystrophy (CRD) and an isolated Dutch individual (family B) with achromatopsia (ACHM) that evolved into a progressive retinal dystrophy. Affected individuals in family A were homozygous for c.317G>C [p.Arg106Pro]. The affected individual in family B was compound heterozygous for 3 nt deletion, c.199_201del (p.Gln67del), and a mutation affecting a canonical splice-site nucleotide, c.810+1G>T. The splice site variant is preIn both families the variants segregated as expected in the family.

PMID: 29220607 - Kominami et al 2018- 1 case. 20-year-old Japanese man whose chief complaint was a progressive decrease in his central vision. Whole-exome sequence with targeted analysis identified new compound heterozygous mutations of c.G1355A (p R452Q) and c.C987A (pY329X) in the POC1B gene. The patient was then diagnosed with cone dystrophy. No access to full article.

PMID: 29377742 - Jin et al 2018 - 1 case - a Chinese family with peripheral cone dystrophy (PCD). The novel compound heterozygous mutation, c.1354C>T and c.710A>G, in POC1B was identified in the patient, the mutations were segregated with the PCD phenotype in the family and were absent from ethnically matched control chromosomes. Prediction analysis demonstrated the novel missense mutation, POC1B c.710A>G, might be damaging. No access to full article.

Summary - 6 cases of homozygous or compound heterozygous variants in POC1B and retinal dystrophy. 1 case plus zebrafish model of multisystem ciliopathy.
Created: 20 Jun 2019, 10:22 p.m. | Last Modified: 20 Jun 2019, 10:22 p.m.
Panel Version: 1.111

Zornitza Stark (Australian Genomics)

Green List (high evidence)

While the majority of reported cases have had retinal dystrophy only (PubMed IDs 25018096, 24945461, 29220607, 29377742), please note this report of multi-system disease and animal model that also had multi-system features.
Created: 7 Aug 2018, 4:33 a.m.

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal


Variants in this GENE are reported as part of current diagnostic practice

Alice Gardham (Genomics England)

Comment when marking as ready: Retinal phenotype only and only identified in two families
Created: 25 Jan 2017, 2:01 p.m.

Penny Clouston (Oxford)

Red List (low evidence)

On current diagnostic panel; no positive families in patient cohort to date. Evidence in literature.
Created: 16 Mar 2016, 9:46 a.m.

Mode of inheritance
BIALLELIC, autosomal or pseudoautosomal

Joubert syndrome; cone-rod dystrophy


Variants in this GENE are reported as part of current diagnostic practice


Mode of Inheritance
BIALLELIC, autosomal or pseudoautosomal
  • Expert Review Amber
  • Expert list
  • Expert Review Amber
  • Senior-Loken Syndrome 24 gene panel
  • Cone-rod dystrophy 20 615973
  • Joubert Syndrome
Clinvar variants
Variants in POC1B
Panels with this gene

History Filter Activity

10 Jul 2019, Gel status: 2

Created, Added New Source, Set mode of inheritance, Set publications, Set Phenotypes

Ivone Leong (Genomics England Curator)

gene: POC1B was added gene: POC1B was added to Ophthalmological ciliopathies. Sources: UKGTN,Expert list,Expert Review Amber Mode of inheritance for gene: POC1B was set to BIALLELIC, autosomal or pseudoautosomal Publications for gene: POC1B were set to 29377742; 25044745; 29220607; 25018096; 24945461 Phenotypes for gene: POC1B were set to Senior-Loken Syndrome 24 gene panel; Cone-rod dystrophy 20 615973; Joubert Syndrome; AUTOSOMAL-RECESSIVE CONE-ROD DYSTROPHY