rs149226993

Positions:

• chr9-97684965-G-A

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_Strong PM2 PP5_Very_Strong

The NM_000380.4(XPA):​c.631C>T​(p.Arg211Ter) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,212 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: XPA NM_000380.4 stop_gained
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:5
• Conservation: PhyloP100: 1.93

Genes affected

XPA (HGNC:12814): (XPA, DNA damage recognition and repair factor) This gene encodes a zinc finger protein plays a central role in nucleotide excision repair (NER), a specialized type of DNA repair. NER is responsible for repair of UV radiation-induced photoproducts and DNA adducts induced by chemical carcinogens and chemotherapeutic drugs. The encoded protein interacts with DNA and several NER proteins, acting as a scaffold to assemble the NER incision complex at sites of DNA damage. Mutations in this gene cause Xeroderma pigmentosum complementation group A (XP-A), an autosomal recessive skin disorder featuring hypersensitivity to sunlight and increased risk for skin cancer. [provided by RefSeq, Aug 2017]

ACMG classification

Verdict is Pathogenic. Variant got 14 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. There are 19 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 9-97684965-G-A is Pathogenic according to our data. Variant chr9-97684965-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 551809.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr9-97684965-G-A is described in Lovd as [Likely_pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
XPA	NM_000380.4	c.631C>T	p.Arg211Ter	stop_gained	5/6	ENST00000375128.5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
XPA	ENST00000375128.5	c.631C>T	p.Arg211Ter	stop_gained	5/6	1	NM_000380.4	P1
XPA	ENST00000496104.1	n.425C>T		non_coding_transcript_exon_variant	4/4	3
XPA	ENST00000462523.5	c.631C>T	p.Arg211Ter	stop_gained, NMD_transcript_variant	5/7	5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251114 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135728

Gnomad AFR exome AF: 0.0000616

Gnomad AMR exome AF: 0.00

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: 0.00000342 AC: 5 AN: 1461212 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726928

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000180

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.0000113

ESP6500AA AF: 0.000227 AC: 1

ESP6500EA AF: 0.00 AC: 0

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:5

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Xeroderma pigmentosum group A Pathogenic:2

Likely pathogenic, criteria provided, single submitter	clinical testing	Counsyl	May 09, 2017	- -
Pathogenic, criteria provided, single submitter	clinical testing	Baylor Genetics	Oct 30, 2023	- -

not provided Pathogenic:2

Pathogenic, criteria provided, single submitter	clinical testing	Invitae	Jan 03, 2024	This sequence change creates a premature translational stop signal (p.Arg211*) in the XPA gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 63 amino acid(s) of the XPA protein. This variant is present in population databases (rs149226993, gnomAD 0.007%). This premature translational stop signal has been observed in individuals with xeroderma pigmentosum (PMID: 1372103, 27607234). ClinVar contains an entry for this variant (Variation ID: 551809). This variant disrupts a region of the XPA protein in which other variant(s) (p.Arg228*) have been determined to be pathogenic (PMID: 8105686, 9671271, 24135642, 27607234). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. For these reasons, this variant has been classified as Pathogenic. -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Apr 06, 2022	Nonsense variant in the C-terminus predicted to result in protein truncation, as the last 63 amino acids are lost, and other loss-of-function variants have been reported downstream in HGMD; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 25525159, 1372103, 15214909, 31350202, 27607234) -

Xeroderma pigmentosum Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

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

Nov 29, 2018

Variant summary: XPA c.631C>T (p.Arg211X) 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. The variant allele was found at a frequency of 4.1e-06 in 245906 control chromosomes (gnomAD). c.631C>T has been reported in the literature in multiple homozygote and compound heterozygote individuals affected with Xeroderma Pigmentosum (Satokata_1992, Zhou_2017). These data indicate that the variant is very likely to be associated with disease. A functional study indicates that the variant would "cause instability of the XPAC mRNA and loss of repair activity of the XPAC protein." (Satokata_1992) A ClinVar submission from a clinical diagnostic laboratory (evaluation after 2014) cties the variant as likely pathogenic. Based on the evidence outlined above, the variant was classified as pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.49	D
BayesDel_noAF	Pathogenic	0.58
CADD	Pathogenic	38
DANN	Uncertain	1.0
Eigen	Uncertain	0.61
Eigen_PC	Uncertain	0.45
FATHMM_MKL	Uncertain	0.90	D
MutationTaster	Benign	1.0	D
Vest4		0.96
GERP RS		3.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

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: rs149226993; hg19: chr9-100447247; COSMIC: COSV105318953;