12-89421235-C-T

Variant names:

• chr12-89421235-C-T
• rs200082142
• NM_172240.3:c.1355G>A

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 2P and 1B. PM2 BP4

The NM_172240.3(POC1B):​c.1355G>A​(p.Arg452Gln) variant causes a missense change. The variant allele was found at a frequency of 0.00000814 in 1,598,018 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000069 (0 hom.)
• Consequence: POC1B NM_172240.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.31

Genes affected

POC1B (HGNC:30836): (POC1 centriolar protein B) POC1 proteins contain an N-terminal WD40 domain and a C-terminal coiled coil domain and are part of centrosomes. They play an important role in basal body and cilia formation. This gene encodes one of the two POC1 proteins found in humans. Mutation in this gene result in autosomal-recessive cone-rod dystrophy. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Oct 2014]

LOC124902981 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.37996703).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POC1B	NM_172240.3	c.1355G>A	p.Arg452Gln	missense_variant	Exon 12 of 12	ENST00000313546.8	NP_758440.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POC1B	ENST00000313546.8	c.1355G>A	p.Arg452Gln	missense_variant	Exon 12 of 12	1	NM_172240.3	ENSP00000323302.3

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152140 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000724

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000286 AC: 7 AN: 244738 Hom.: 0 AF XY: 0.0000227 AC XY: 3 AN XY: 132142

Gnomad AFR exome AF: 0.000259

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000546

Gnomad SAS exome AF: 0.0000672

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000692 AC: 10 AN: 1445878 Hom.: 0 Cov.: 30 AF XY: 0.00000697 AC XY: 5 AN XY: 717272

Gnomad4 AFR exome AF: 0.0000600

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000760

Gnomad4 SAS exome AF: 0.0000354

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000182

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152140 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 74312

Gnomad4 AFR AF: 0.0000724

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000162 Hom.: 0

Bravo AF: 0.0000453

ExAC AF: 0.0000165 AC: 2

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Oct 11, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces arginine with glutamine at codon 452 of the POC1B protein (p.Arg452Gln). The arginine residue is highly conserved and there is a small physicochemical difference between arginine and glutamine. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Possibly Damaging"; Align-GVGD: "Class C0"). This missense change has been observed in individual(s) with clinical features of POC1B-related conditions (PMID: 29220607). In at least one individual the data is consistent with the variant being in trans (on the opposite chromosome) from a pathogenic variant. This variant is present in population databases (rs200082142, ExAC 0.01%). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.81
BayesDel_addAF	Benign	-0.041	T
BayesDel_noAF	Uncertain	-0.010
CADD	Pathogenic	29
DANN	Pathogenic	1.0
DEOGEN2	Uncertain	0.56	.;D;.
Eigen	Uncertain	0.66
Eigen_PC	Pathogenic	0.67
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Pathogenic	0.98	D;D;D
M_CAP	Uncertain	0.19	D
MetaRNN	Benign	0.38	T;T;T
MetaSVM	Uncertain	-0.10	T
MutationAssessor	Uncertain	2.5	.;M;.
PROVEAN	Uncertain	-3.4	D;D;D
REVEL	Uncertain	0.60
Sift	Pathogenic	0.0	D;D;D
Sift4G	Uncertain	0.0040	D;D;D
Polyphen		0.99	.;D;.
Vest4		0.42
MVP		0.85
MPC		0.32
ClinPred		0.77	D
GERP RS		5.6
Varity_R		0.77
gMVP		0.43

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs200082142; hg19: chr12-89815012;