NM_003401.5:c.166G>A

Variant names:

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 0P and 4B. BS2

The NM_003401.5(XRCC4):c.166G>A(p.Ala56Thr) variant causes a missense change. The variant allele was found at a frequency of 0.000786 in 1,608,256 control chromosomes in the GnomAD database, including 3 homozygotes. Variant has been reported in ClinVar as Uncertain significance (★★).

Frequency

Genomes: 𝑓 0.00053 ( 0 hom., cov: 33)

Exomes 𝑓: 0.00081 ( 3 hom. )

Consequence

XRCC4
NM_003401.5 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:3

Conservation

PhyloP100: 6.49

Publications

14 publications found

Variant links:

Genes affected

XRCC4 (HGNC:12831): (X-ray repair cross complementing 4) The protein encoded by this gene functions together with DNA ligase IV and the DNA-dependent protein kinase in the repair of DNA double-strand breaks. This protein plays a role in both non-homologous end joining and the completion of V(D)J recombination. Mutations in this gene can cause short stature, microcephaly, and endocrine dysfunction (SSMED). Alternate transcript variants such as NM_022406 are unlikely to be expressed in some individuals due to a polymorphism (rs1805377) in the last splice acceptor site. [provided by RefSeq, Oct 2019]

XRCC4 Gene-Disease associations (from GenCC):

short stature, microcephaly, and endocrine dysfunction
Inheritance: AR Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), G2P, Laboratory for Molecular Medicine
microcephalic primordial dwarfism-insulin resistance syndrome
Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
hereditary nonpolyposis colon cancer
Inheritance: AD Classification: LIMITED Submitted by: ClinGen

XRCC4 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -4 ACMG points.

BS2

High Homozygotes in GnomAdExome4 at 3 AD,AR gene

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
XRCC4	NM_003401.5 link	c.166G>A	p.Ala56Thr	missense_variant	Exon 3 of 8	ENST00000396027.9	NP_003392.1	Q13426-2A0A024RAL0Q7Z763

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
XRCC4	ENST00000396027.9 link	c.166G>A	p.Ala56Thr	missense_variant	Exon 3 of 8	5	NM_003401.5	ENSP00000379344.4		Q13426-2

Frequencies

GnomAD3 genomes

AF:

0.000533

AC:

AN:

152052

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.000720

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:

0.000839

Gnomad OTH

AF:

0.00144

GnomAD2 exomes

AF:

0.000429

AC:

105

AN:

244886

AF XY:

0.000400

show subpopulations

Gnomad AFR exome

AF:

0.000125

Gnomad AMR exome

AF:

0.000758

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.000681

Gnomad OTH exome

AF:

0.000336

GnomAD4 exome

AF:

0.000812

AC:

1183

AN:

1456086

Hom.:

Cov.:

AF XY:

0.000787

AC XY:

570

AN XY:

724190

show subpopulations

African (AFR)

AF:

0.000181

AC:

AN:

33132

American (AMR)

AF:

0.000896

AC:

AN:

43530

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

25996

East Asian (EAS)

AF:

0.00

AC:

AN:

39364

South Asian (SAS)

AF:

0.00

AC:

AN:

84602

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53366

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5752

European-Non Finnish (NFE)

AF:

0.000985

AC:

1093

AN:

1110182

Other (OTH)

AF:

0.000748

AC:

AN:

60162

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.452

Heterozygous variant carriers

117

175

234

292

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

GnomAD4 genome

AF:

0.000532

AC:

AN:

152170

Hom.:

Cov.:

AF XY:

0.000336

AC XY:

AN XY:

74414

show subpopulations

African (AFR)

AF:

0.000241

AC:

AN:

41546

American (AMR)

AF:

0.000720

AC:

AN:

15288

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3472

East Asian (EAS)

AF:

0.00

AC:

AN:

5194

South Asian (SAS)

AF:

0.00

AC:

AN:

4822

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10614

Middle Eastern (MID)

AF:

0.00

AC:

AN:

294

European-Non Finnish (NFE)

AF:

0.000839

AC:

AN:

67922

Other (OTH)

AF:

0.00142

AC:

AN:

2106

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.509

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.000385

Hom.:

Bravo

AF:

0.000691

TwinsUK

AF:

0.000809

AC:

ALSPAC

AF:

0.000519

AC:

ESP6500AA

AF:

0.000227

AC:

ESP6500EA

AF:

0.000698

AC:

ExAC

AF:

0.000404

AC:

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Jun 19, 2025

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Published case-control studies suggest A56T, referred to as rs28383151-GA, may modify the risk and prognosis of hepatocellular carcinoma caused by exposure to aflatoxin B1, a chemical carcinogen (PMID: 23390017, 25337275); In silico analysis, which includes protein predictors and evolutionary conservation, supports a deleterious effect; This variant is associated with the following publications: (PMID: 29452234, 25337275, 23390017, Taha[thesis]2023) -

Oct 13, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces alanine with threonine at codon 56 of the XRCC4 protein (p.Ala56Thr). The alanine residue is highly conserved and there is a small physicochemical difference between alanine and threonine. This variant is present in population databases (rs28383151, gnomAD 0.08%), and has an allele count higher than expected for a pathogenic variant. This variant has not been reported in the literature in individuals affected with XRCC4-related conditions. ClinVar contains an entry for this variant (Variation ID: 1307675). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt XRCC4 protein function. 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. -

Short stature, microcephaly, and endocrine dysfunction

Uncertain:1

Mar 29, 2022

Fulgent Genetics, Fulgent Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.65

BayesDel_addAF

Benign

-0.13

BayesDel_noAF

Uncertain

-0.030

CADD

Pathogenic

(source)

DANN

Pathogenic

1.0

DEOGEN2

Benign

0.32

.;T;.;T

Eigen

Pathogenic

0.82

Eigen_PC

Pathogenic

0.79

FATHMM_MKL

Uncertain

0.96

LIST_S2

Uncertain

0.91

D;.;.;D

M_CAP

Benign

0.064

MetaRNN

Uncertain

0.46

T;T;T;T

MetaSVM

Benign

-0.89

MutationAssessor

Uncertain

2.8

M;M;M;M

PhyloP100

6.5

PrimateAI

Uncertain

0.51

PROVEAN

Uncertain

-3.2

D;D;D;D

REVEL

Uncertain

0.34

Sift

Pathogenic

0.0

D;D;D;D

Sift4G

Pathogenic

0.0

D;D;D;D

Polyphen

1.0

D;D;D;D

Vest4

0.85

MVP

0.35

MPC

0.20

ClinPred

0.21

GERP RS

5.6

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.7

Varity_R

0.56

gMVP

0.40

Mutation Taster

=45/55

disease causing

(source)

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

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NM_003401.5:c.166G>A

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over