rs267608683

Positions:

• chr12-106432361-C-A

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM2 PP2 PP3_Strong PP5

The ENST00000228347.9(POLR3B):​c.1508C>A​(p.Thr503Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,450 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 Pathogenic (no stars).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: POLR3B ENST00000228347.9 missense
• Clinical Significance: Pathogenic no assertion criteria provided P:1 O:1
• Conservation: PhyloP100: 7.54

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 Likely_pathogenic. Variant got 8 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), POLR3B. . Gene score misZ 3.1978 (greater than the threshold 3.09). Trascript score misZ 3.4842 (greater than threshold 3.09). GenCC has associacion of gene with 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, 0.944
• PP5: Variant 12-106432361-C-A is Pathogenic according to our data. Variant chr12-106432361-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 31164.Status of the report is no_assertion_criteria_provided, 0 stars. Variant chr12-106432361-C-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
POLR3B	NM_018082.6	c.1508C>A	p.Thr503Lys	missense_variant	15/28	ENST00000228347.9	NP_060552.4
POLR3B	NM_001160708.2	c.1334C>A	p.Thr445Lys	missense_variant	15/28		NP_001154180.1
POLR3B	XM_017019621.3	c.1508C>A	p.Thr503Lys	missense_variant	15/26		XP_016875110.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
POLR3B	ENST00000228347.9	c.1508C>A	p.Thr503Lys	missense_variant	15/28	1	NM_018082.6	ENSP00000228347	P1
POLR3B	ENST00000539066.5	c.1334C>A	p.Thr445Lys	missense_variant	15/28	2		ENSP00000445721

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461450 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727070

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1 Other:1

Revision: no assertion criteria provided

Submissions by phenotype

Hypomyelinating leukodystrophy 8 with or without oligodontia and-or hypogonadotropic hypogonadism Pathogenic:1 Other:1

not provided, no classification provided	literature only	GeneReviews	-	- -
Pathogenic, no assertion criteria provided	literature only	OMIM	Nov 11, 2011	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.44	D
BayesDel_noAF	Pathogenic	0.39
CADD	Pathogenic	28
DANN	Uncertain	0.99
DEOGEN2	Uncertain	0.79	D;.
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	1.0
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Pathogenic	0.99	D;D
M_CAP	Pathogenic	0.58	D
MetaRNN	Pathogenic	0.94	D;D
MetaSVM	Uncertain	0.65	D
MutationAssessor	Pathogenic	3.8	H;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Pathogenic	0.93	D
PROVEAN	Pathogenic	-5.5	D;D
REVEL	Pathogenic	0.82
Sift	Pathogenic	0.0	D;D
Sift4G	Pathogenic	0.0010	D;D
Polyphen		1.0	D;.
Vest4		0.93
MutPred		0.75		Gain of ubiquitination at T503 (P = 0.0219);.;
MVP		0.88
MPC		1.7
ClinPred		1.0	D
GERP RS		6.1
Varity_R		0.93
gMVP		0.96

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs267608683; hg19: chr12-106826139;