13-108209234-C-T

Variant names:

• chr13-108209234-C-T
• rs957569908
• NM_206937.2:c.2035G>A

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM2 PP3_Moderate

The NM_206937.2(LIG4):​c.2035G>A​(p.Glu679Lys) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,850 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. E679Q) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: LIG4 NM_206937.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 7.83
• Publications: 0 publications found

Genes affected

LIG4 (HGNC:6601): (DNA ligase 4) The protein encoded by this gene is a DNA ligase that joins single-strand breaks in a double-stranded polydeoxynucleotide in an ATP-dependent reaction. This protein is essential for V(D)J recombination and DNA double-strand break (DSB) repair through nonhomologous end joining (NHEJ). This protein forms a complex with the X-ray repair cross complementing protein 4 (XRCC4), and further interacts with the DNA-dependent protein kinase (DNA-PK). Both XRCC4 and DNA-PK are known to be required for NHEJ. The crystal structure of the complex formed by this protein and XRCC4 has been resolved. Defects in this gene are the cause of LIG4 syndrome. Alternatively spliced transcript variants encoding the same protein have been observed. [provided by RefSeq, Jul 2008]

LIG4 Gene-Disease associations (from GenCC):

• DNA ligase IV deficiency

  Inheritance: AR Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), Orphanet, G2P
• Dubowitz syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• Omenn syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.869

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_206937.2. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LIG4	NM_206937.2	MANE Select	c.2035G>A	p.Glu679Lys	missense	Exon 3 of 3	NP_996820.1
	LIG4	NM_001352604.2		c.2071G>A	p.Glu691Lys	missense	Exon 3 of 3	NP_001339533.1
	LIG4	NM_001098268.2		c.2035G>A	p.Glu679Lys	missense	Exon 2 of 2	NP_001091738.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	LIG4	ENST00000442234.6	TSL:1 MANE Select	c.2035G>A	p.Glu679Lys	missense	Exon 3 of 3	ENSP00000402030.1
	LIG4	ENST00000405925.2	TSL:1	c.2035G>A	p.Glu679Lys	missense	Exon 2 of 2	ENSP00000385955.1
	LIG4	ENST00000611712.4	TSL:4	c.2035G>A	p.Glu679Lys	missense	Exon 3 of 3	ENSP00000484288.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461850 Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0 AN XY: 727226

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33480

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39698

South Asian (SAS) AF: 0.00 AC: 0 AN: 86256

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53408

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5768

European-Non Finnish (NFE) AF: 8.99e-7 AC: 1 AN: 1111984

Other (OTH) AF: 0.00 AC: 0 AN: 60396

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

DNA ligase IV deficiency Uncertain:1

Aug 17, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. 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 LIG4 protein function. ClinVar contains an entry for this variant (Variation ID: 1429192). This variant has not been reported in the literature in individuals affected with LIG4-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces glutamic acid, which is acidic and polar, with lysine, which is basic and polar, at codon 679 of the LIG4 protein (p.Glu679Lys).

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.79
BayesDel_addAF	Pathogenic	0.28	D
BayesDel_noAF	Pathogenic	0.17
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Uncertain	0.56	D
Eigen	Pathogenic	0.86
Eigen_PC	Pathogenic	0.79
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.90	D
M_CAP	Uncertain	0.11	D
MetaRNN	Pathogenic	0.87	D
MetaSVM	Uncertain	0.57	D
MutationAssessor	Pathogenic	3.4	M
PhyloP100		7.8
PrimateAI	Uncertain	0.62	T
PROVEAN	Uncertain	-3.0	D
REVEL	Pathogenic	0.78
Sift	Uncertain	0.0040	D
Sift4G	Uncertain	0.010	D
Polyphen		1.0	D
Vest4		0.78
MutPred		0.64		Gain of ubiquitination at E679 (P = 0.0177)
MVP		0.84
MPC		0.34
ClinPred		0.96	D
GERP RS		5.7
Varity_R		0.87
gMVP		0.92
Mutation Taster		=36/64	disease causing

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

Other links and lift over

dbSNP: rs957569908; hg19: chr13-108861582;