10-78009539-G-C

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PM5 PP2 PP3_Moderate

The NM_007055.4(POLR3A):c.1907C>G(p.Ser636Cys) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000657 in 152,170 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S636Y) has been classified as Uncertain significance.

• Frequency: Genomes: 𝑓 0.0000066 (0 hom., cov: 32)
• Consequence: POLR3A NM_007055.4 missense, splice_region
• Scores: Splicing: ADA: 0.9384
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.49

Genes affected

POLR3A (HGNC:30074): (RNA polymerase III subunit A) The protein encoded by this gene is the catalytic component of RNA polymerase III, which synthesizes small RNAs. The encoded protein also acts as a sensor to detect foreign DNA and trigger an innate immune response. [provided by RefSeq, Aug 2011]

ACMG classification

Verdict is Likely_pathogenic. Variant got 7 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr10-78009539-G-T is described in Lovd as [Pathogenic].
• PP2: Missense variant where missense usually causes diseases, POLR3A
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.914

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
POLR3A	NM_007055.4	c.1907C>G	p.Ser636Cys	missense_variant, splice_region_variant	14/31	ENST00000372371.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POLR3A	ENST00000372371.8	c.1907C>G	p.Ser636Cys	missense_variant, splice_region_variant	14/31	1	NM_007055.4	P1

Frequencies

GnomAD3 genomes AF: 0.00000657 AC: 1 AN: 152170 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000655

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

GnomAD4 exome Cov.: 32

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152170 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74332

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.0000655

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

Bravo AF: 0.0000227

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jul 14, 2022

This variant is not present in population databases (gnomAD no frequency). 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: "Benign"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals affected with POLR3A-related conditions. This sequence change replaces serine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 636 of the POLR3A protein (p.Ser636Cys). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.47
BayesDel_addAF	Pathogenic	0.32	D
BayesDel_noAF	Pathogenic	0.22
Cadd	Pathogenic	32
Dann	Uncertain	0.99
DEOGEN2	Uncertain	0.63	D
Eigen	Pathogenic	0.91
Eigen_PC	Pathogenic	0.90
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.96	D
M_CAP	Benign	0.080	D
MetaRNN	Pathogenic	0.91	D
MetaSVM	Uncertain	-0.15	T
MutationAssessor	Uncertain	2.7	M
MutationTaster	Benign	1.0	D
PrimateAI	Uncertain	0.67	T
PROVEAN	Uncertain	-4.0	D
REVEL	Pathogenic	0.71
Sift	Uncertain	0.0090	D
Sift4G	Uncertain	0.022	D
Polyphen		1.0	D
Vest4		0.87
MutPred		0.72		Loss of disorder (P = 0.0377);
MVP		0.92
MPC		0.53
ClinPred		0.99	D
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.74
gMVP		0.82

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.94
dbscSNV1_RF	Benign	0.64
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: rs267608676; hg19: chr10-79769297;