chr12-106357934-C-G

Variant names:

• chr12-106357934-C-G
• NM_018082.6:c.55C>G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 3P and 1B. PM2 PP2 BP4

The NM_018082.6(POLR3B):​c.55C>G​(p.Pro19Ala) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: POLR3B NM_018082.6 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 6.48

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• 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.
• BP4: Computational evidence support a benign effect (MetaRNN=0.33520788).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
POLR3B	NM_018082.6	c.55C>G	p.Pro19Ala	missense_variant	Exon 1 of 28	ENST00000228347.9	NP_060552.4
POLR3B	XM_017019621.3	c.55C>G	p.Pro19Ala	missense_variant	Exon 1 of 26		XP_016875110.1
POLR3B	NM_001160708.2	c.-391C>G		upstream_gene_variant			NP_001154180.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
POLR3B	ENST00000228347.9	c.55C>G	p.Pro19Ala	missense_variant	Exon 1 of 28	1	NM_018082.6	ENSP00000228347.4
POLR3B	ENST00000539066.5	c.-391C>G		upstream_gene_variant		2		ENSP00000445721.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Jul 09, 2024

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Uncertain	0.15	D
BayesDel_noAF	Uncertain	-0.030
CADD	Uncertain	24
DANN	Uncertain	1.0
DEOGEN2	Benign	0.28	T
Eigen	Benign	0.038
Eigen_PC	Uncertain	0.24
FATHMM_MKL	Uncertain	0.94	D
LIST_S2	Benign	0.84	T
M_CAP	Benign	0.057	D
MetaRNN	Benign	0.34	T
MetaSVM	Benign	-0.61	T
MutationAssessor	Benign	1.9	L
PrimateAI	Uncertain	0.63	T
PROVEAN	Pathogenic	-5.2	D
REVEL	Uncertain	0.35
Sift	Benign	0.030	D
Sift4G	Uncertain	0.048	D
Polyphen		0.18	B
Vest4		0.46
MutPred		0.46		Loss of stability (P = 0.0625);
MVP		0.61
MPC		0.74
ClinPred		1.0	D
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.43
gMVP		0.58

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr12-106751712;