Genetic Variant LIG4:p.Arg505CysfsTer12 (chr13-108209755-CGA-C) – ACMG Classification: Pathogenic (14 pts)

Variant summary

Our verdict is Pathogenic. Variant got 14 ACMG points: 14P and 0B. PVS1_StrongPM2PP5_Very_Strong

The NM_206937.2(LIG4):c.1512_1513delTC(p.Arg505CysfsTer12) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000124 in 1,613,978 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Pathogenic (★★).

Frequency

Genomes: 𝑓 0.000013 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000012 ( 0 hom. )

Consequence

LIG4
NM_206937.2 frameshift

Scores

Not classified

Clinical Significance

Pathogenic criteria provided, multiple submitters, no conflicts P:6

Conservation

PhyloP100: 9.82

Variant links:

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

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 exon, not predicted to undergo nonsense mediated mRNA decay. There are 4 pathogenic variants in the truncated region.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 13-108209755-CGA-C is Pathogenic according to our data. Variant chr13-108209755-CGA-C is described in ClinVar as [Pathogenic]. Clinvar id is 433156.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr13-108209755-CGA-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LIG4	NM_206937.2 link	c.1512_1513delTC	p.Arg505CysfsTer12	frameshift_variant	Exon 3 of 3	ENST00000442234.6	NP_996820.1	P49917A0A024RE06

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LIG4	ENST00000442234.6 link	c.1512_1513delTC	p.Arg505CysfsTer12	frameshift_variant	Exon 3 of 3	1	NM_206937.2	ENSP00000402030.1		P49917

Frequencies

GnomAD3 genomes

AF:

0.0000131

AC:

AN:

152128

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000483

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:

0.00

Gnomad OTH

AF:

0.00

GnomAD4 exome

AF:

0.0000123

AC:

AN:

1461850

Hom.:

AF XY:

0.0000124

AC XY:

AN XY:

727222

show subpopulations

Gnomad4 AFR exome

AF:

0.000119

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000252

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.0000108

Gnomad4 OTH exome

AF:

0.0000166

GnomAD4 genome

AF:

0.0000131

AC:

AN:

152128

Hom.:

Cov.:

AF XY:

0.0000135

AC XY:

AN XY:

74320

show subpopulations

Gnomad4 AFR

AF:

0.0000483

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:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.0000416

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:6

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

DNA ligase IV deficiency

Pathogenic:3

Mar 28, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Arg505Cysfs*12) in the LIG4 gene. While this is not anticipated to result in nonsense mediated decay, it is expected to disrupt the last 407 amino acid(s) of the LIG4 protein. This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with microcephalic primordial dwarfism (PMID: 24123394). ClinVar contains an entry for this variant (Variation ID: 433156). This variant disrupts a region of the LIG4 protein in which other variant(s) (p.Arg814*) have been determined to be pathogenic (PMID: 11779494, 16088910, 25239263, 27063650, 27612988). 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. -

Apr 20, 2023

Duke University Health System Sequencing Clinic, Duke University Health System

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

- -

Apr 02, 2024

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

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Variant summary: LIG4 c.1512_1513delTC (p.Arg505CysfsX12) results in a premature termination codon in the last exon (exon 2), predicted to cause a truncation of the encoded protein. Although, nonsense mediated decay is not expected to occur, multiple downstream loss of function variants have been classified as pathogenic in ClinVar. The variant was absent in 251388 control chromosomes. c.1512_1513delTC has been reported in the literature in at least one compound heterozygous individual affected with LIG4 Syndrome (e.g. Murray_2014). To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication has been ascertained in the context of this evaluation (PMID: 24123394). ClinVar contains an entry for this variant (Variation ID: 433156). Based on the evidence outlined above, the variant was classified as pathogenic. -

not provided

Pathogenic:1

Jan 06, 2016

Molecular Diagnostics Lab, Nemours Children's Health, Delaware

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Multiple myeloma;C1847827:DNA ligase IV deficiency

Pathogenic:1

Apr 11, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

prenatal LIG4 syndrome with aqueductal stenosis

Pathogenic:1

Dec 28, 2023

Molecular Genetics laboratory, Necker Hospital

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

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

Below is the list of publications found by LitVar. It may be empty.

13-108209755-CGAGA-CGA

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over