NM_018082.6:c.3173A>G

Variant names:

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PP2PP3_Strong

The NM_018082.6(POLR3B):c.3173A>G(p.Tyr1058Cys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000682 in 1,614,046 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000068 ( 0 hom. )

Consequence

POLR3B
NM_018082.6 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1U:3

Conservation

PhyloP100: 9.29

Variant links:

Genes affected

POLR3B (HGNC:30348): (RNA polymerase III subunit B) This gene encodes the second largest subunit of RNA polymerase III, the polymerase responsible for synthesizing transfer and small ribosomal RNAs in eukaryotes. The largest subunit and the encoded protein form the catalytic center of RNA polymerase III. Mutations in this gene are a cause of hypomyelinating leukodystrophy. Alternatively spliced transcript variants encoding multiple isoforms have been observed for this gene. [provided by RefSeq, Dec 2011]

POLR3B links:

ENSG00000257545 (HGNC:):

ENSG00000257545 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Uncertain_significance. Variant got 5 ACMG points.

PP2

Missense variant in the POLR3B gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 24 curated pathogenic missense variants (we use a threshold of 10). The gene has 6 curated benign missense variants. Gene score misZ: 3.1978 (above the threshold of 3.09). Trascript score misZ: 3.4842 (above the threshold of 3.09). GenCC associations: The gene is linked to hypomyelination-hypogonadotropic hypogonadism-hypodontia syndrome, Charcot-Marie-Tooth disease, demyelinating, IIA 1I, hypomyelinating leukodystrophy 8 with or without oligodontia and-or hypogonadotropic hypogonadism, endosteal sclerosis-cerebellar hypoplasia syndrome.

PP3

MetaRNN computational evidence supports a deleterious effect, 0.984

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POLR3B	NM_018082.6 link	c.3173A>G	p.Tyr1058Cys	missense_variant	Exon 27 of 28	ENST00000228347.9	NP_060552.4	Q9NW08-1Q7Z3R8
POLR3B	NM_001160708.2 link	c.2999A>G	p.Tyr1000Cys	missense_variant	Exon 27 of 28		NP_001154180.1	Q9NW08-2
LOC100287944	NR_040246.1 link	n.325+3473T>C		intron_variant	Intron 2 of 3

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
POLR3B	ENST00000228347.9 link	c.3173A>G	p.Tyr1058Cys	missense_variant	Exon 27 of 28	1	NM_018082.6	ENSP00000228347.4	Q9NW08-1
POLR3B	ENST00000539066.5 link	c.2999A>G	p.Tyr1000Cys	missense_variant	Exon 27 of 28	2		ENSP00000445721.1	Q9NW08-2
ENSG00000257545	ENST00000549203.2 link	n.325+3473T>C		intron_variant	Intron 2 of 3	4
ENSG00000257545	ENST00000551505.4 link	n.230-3973T>C		intron_variant	Intron 1 of 2	4

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152260

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.0000654

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:

0.0000358

AC:

AN:

251476

Hom.:

AF XY:

0.0000368

AC XY:

AN XY:

135910

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.000260

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.00000684

AC:

AN:

1461786

Hom.:

Cov.:

AF XY:

0.00000825

AC XY:

AN XY:

727218

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.000201

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152260

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74394

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.0000654

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:

0.0000508

Hom.:

Bravo

AF:

0.00000378

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1Uncertain:3

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

Hypomyelinating leukodystrophy 8 with or without oligodontia and-or hypogonadotropic hypogonadism

Pathogenic:1Uncertain:1

Feb 28, 2022

Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: curation

The p.Tyr1058Cys variant in POLR3B has not been previously reported in the literature in individuals with 4H leukodystrophy but has been identified in 0.03% (9/34588) of Latino/Admixed American chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP ID: rs751459271). Although this variant has been seen in the general population in a heterozygous state, its frequency is not high enough to rule out a pathogenic role. This variant has also been reported in ClinVar (Variation ID#: 211934) and has been interpreted as likely pathogenic by Genetic Services Laboratory (University of Chicago). Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. The number of missense variants reported in POLR3B in the general population is lower than expected, suggesting there is little benign variation in this gene and slightly increasing the possibility that a missense variant in this gene may not be tolerated. In summary, the clinical significance of the p.Tyr1058Cys variant is uncertain. ACMG/AMP Criteria applied: PP3, PP2 (Richards 2015). -

Dec 05, 2014

Genetic Services Laboratory, University of Chicago

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Inborn genetic diseases

Uncertain:1

Mar 20, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.3173A>G (p.Y1058C) alteration is located in exon 27 (coding exon 27) of the POLR3B gene. This alteration results from a A to G substitution at nucleotide position 3173, causing the tyrosine (Y) at amino acid position 1058 to be replaced by a cysteine (C). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

not provided

Uncertain:1

Nov 11, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 1058 of the POLR3B protein (p.Tyr1058Cys). This variant is present in population databases (rs751459271, gnomAD 0.03%). This missense change has been observed in individual(s) with leukodystrophy (internal data). In at least one individual the data is consistent with being in trans (on the opposite chromosome) from a pathogenic variant. ClinVar contains an entry for this variant (Variation ID: 211934). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) indicates that this missense variant is expected to disrupt POLR3B protein function with a positive predictive value of 80%. 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. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.60

BayesDel_addAF

Pathogenic

0.25

BayesDel_noAF

Pathogenic

0.41

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Uncertain

0.51

D;.

Eigen

Pathogenic

1.1

Eigen_PC

Pathogenic

1.0

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Pathogenic

0.99

D;D

M_CAP

Pathogenic

0.65

MetaRNN

Pathogenic

0.98

D;D

MetaSVM

Pathogenic

0.99

MutationAssessor

Pathogenic

4.2

H;.

PrimateAI

Pathogenic

0.91

PROVEAN

Pathogenic

-8.3

D;D

REVEL

Pathogenic

0.92

Sift

Uncertain

0.0010

D;D

Sift4G

Uncertain

0.0020

D;D

Polyphen

1.0

D;.

Vest4

0.95

MutPred

0.89

Gain of disorder (P = 0.0269);.;

MVP

0.95

MPC

1.8

ClinPred

1.0

GERP RS

5.5

Varity_R

0.83

gMVP

0.95

Splicing

Name

Calibrated prediction

Score

Prediction

SpliceAI score (max)

0.0

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over