6-43610556-T-TG

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_006502.3(POLH):c.1078dup(p.Asp360GlyfsTer32) variant causes a frameshift change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000744 in 1,613,768 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: 𝑓 0.000026 (0 hom., cov: 31)
  • Exomes 𝑓: 0.0000055 (0 hom.)
• Consequence: POLH NM_006502.3 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 2.53

Genes affected

POLH (HGNC:9181): (DNA polymerase eta) This gene encodes a member of the Y family of specialized DNA polymerases. It copies undamaged DNA with a lower fidelity than other DNA-directed polymerases. However, it accurately replicates UV-damaged DNA; when thymine dimers are present, this polymerase inserts the complementary nucleotides in the newly synthesized DNA, thereby bypassing the lesion and suppressing the mutagenic effect of UV-induced DNA damage. This polymerase is thought to be involved in hypermutation during immunoglobulin class switch recombination. Mutations in this gene result in XPV, a variant type of xeroderma pigmentosum. Several transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, May 2014]

POLR1C (HGNC:):

GTPBP2 (HGNC:4670): (GTP binding protein 2) GTP-binding proteins, or G proteins, constitute a superfamily capable of binding GTP or GDP. G proteins are activated by binding GTP and are inactivated by hydrolyzing GTP to GDP. This general mechanism enables G proteins to perform a wide range of biologic activities.[supplied by OMIM, Jan 2003]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 6-43610556-T-TG is Pathogenic according to our data. Variant chr6-43610556-T-TG is described in ClinVar as [Pathogenic]. Clinvar id is 1696282.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
POLH	NM_006502.3	c.1078dup	p.Asp360GlyfsTer32	frameshift_variant	10/11	ENST00000372236.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
POLH	ENST00000372236.9	c.1078dup	p.Asp360GlyfsTer32	frameshift_variant	10/11	1	NM_006502.3	P1
POLH	ENST00000372226.1	c.1078dup	p.Asp360GlyfsTer32	frameshift_variant	10/11	1
GTPBP2	ENST00000496137.5	c.*132-5175_*132-5174insC		intron_variant, NMD_transcript_variant		3

Frequencies

GnomAD3 genomes AF: 0.0000263 AC: 4 AN: 152140 Hom.: 0 Cov.: 31

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD4 exome AF: 0.00000547 AC: 8 AN: 1461628 Hom.: 0 Cov.: 31 AF XY: 0.00000275 AC XY: 2 AN XY: 727136

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000630

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000263 AC: 4 AN: 152140 Hom.: 0 Cov.: 31 AF XY: 0.0000269 AC XY: 2 AN XY: 74310

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: 0.0000147

Gnomad4 OTH AF: 0.00

Bravo AF: 0.0000113

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Xeroderma pigmentosum Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

May 11, 2022

Variant summary: POLH c.1078dupG (p.Asp360GlyfsX32) results in a premature termination codon, predicted to cause a truncation of the encoded protein or absence of the protein due to nonsense mediated decay, which are commonly known mechanisms for disease. Truncations downstream of this position have been classified as pathogenic in other databases (ClinVar, HGMD). The variant was absent in 251292 control chromosomes. c.1078dupG has been reported in the literature in individuals affected with Xeroderma Pigmentosum. These data indicate that the variant is likely to be associated with disease. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014. Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Feb 05, 2023

This sequence change creates a premature translational stop signal (p.Asp360Glyfs*32) in the POLH gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in POLH are known to be pathogenic (PMID: 11773631, 24130121, 25256075). This variant is present in population databases (no rsID available, gnomAD 0.01%). This premature translational stop signal has been observed in individual(s) with POLH-related conditions (PMID: 10398605, 31980526). This variant is also known as +1 G at +1078. ClinVar contains an entry for this variant (Variation ID: 1696282). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

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

Other links and lift over

dbSNP: rs1277794845; hg19: chr6-43578293;