NM_000234.3:c.2311C>T
Variant summary
Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B.
The NM_000234.3(LIG1):c.2311C>T(p.Arg771Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000026 in 1,613,568 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 Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R771Q) has been classified as Uncertain significance.
Frequency
Consequence
NM_000234.3 missense
Scores
Clinical Significance
Conservation
Publications
- immunodeficiency 96Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
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ACMG classification
Our verdict: Likely_pathogenic. The variant received 7 ACMG points.
Transcripts
RefSeq
Ensembl
Frequencies
GnomAD3 genomes AF: 0.00000657 AC: 1AN: 152136Hom.: 0 Cov.: 32 show subpopulations
GnomAD2 exomes AF: 0.0000361 AC: 9AN: 248984 AF XY: 0.0000222 show subpopulations
GnomAD4 exome AF: 0.0000281 AC: 41AN: 1461432Hom.: 0 Cov.: 31 AF XY: 0.0000179 AC XY: 13AN XY: 727026 show subpopulations
Age Distribution
GnomAD4 genome AF: 0.00000657 AC: 1AN: 152136Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1AN XY: 74336 show subpopulations
ClinVar
Submissions by phenotype
Immunodeficiency 96 Pathogenic:3Uncertain:1
ACMG classification criteria: PS3 supporting, PM2 supporting, PM3 moderated, PP1 supporting, PP3 supporting -
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The heterozygous p.Arg771Trp variant in LIG1 was identified by our study, in the compound heterozygous state along with a variant of uncertain significance (Variation ID: 1145405), in 1 individual with LIG1 immunodeficiency 96. Trio genome analysis revealed that this variant was in trans with the variant of uncertain significance. The p.Arg771Trp variant in LIG1 has been reported in 4 individuals with LIG1 immunodeficiency 96 (PMID: 30395541,1581963), and has been identified in 0.002% (32/1179888) of European (non-Finnish) chromosomes by the Genome Aggregation Database (gnomAD, http://gnomad.broadinstitute.org; dbSNP rs121434561). Although this variant has been seen in the general population in a heterozygous state, its frequency is low enough to be consistent with a recessive carrier frequency. This variant has also been reported in ClinVar (Variation ID: 16776) and has been interpreted as pathogenic/likely pathogenic by OMIM and Laboratorio de Genetica e Diagnostico Molecular (Hospital Israelita Albert Einstein), and as a variant of uncertain significance by Labcorp Genetics and Fulgent Genetics. Of the 4 affected individuals, 1 was a compound heterozygote that carried a reported pathogenic variant in trans, which increases the likelihood that the p.Arg771Trp variant is pathogenic (Variation ID: 16775; PMID: 1581963). In vitro functional studies provide some evidence that the p.Arg771Trp variant may impact protein function (PMID: 30395541, 32914844). However, these types of assays may not accurately represent biological function. Computational prediction tools and conservation analyses suggest that this variant may impact the protein, though this information is not predictive enough to determine pathogenicity. In summary, although additional studies are required to fully establish its clinical significance, this variant is likely pathogenic for autosomal recessive LIG1 immunodeficiency 96. ACMG/AMP Criteria applied: PP3_moderate, PS3_moderate, PM3, PM2_supporting (Richards 2015). -
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not provided Uncertain:2
This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 771 of the LIG1 protein (p.Arg771Trp). This variant is present in population databases (rs121434561, gnomAD 0.006%). This missense change has been observed in individual(s) with DNA ligase I deficiency (PMID: 1581963, 30395541). ClinVar contains an entry for this variant (Variation ID: 16776). Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive. Experimental studies have shown that this missense change affects LIG1 function (PMID: 30395541, 32914844, 33600799). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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. -
Published functional studies demonstrate this variant impairs the function of LIG1 (PMID: 32914844, 30395541); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; This variant is associated with the following publications: (PMID: 18440984, 30395541, 33600799, 19223467, 33444456, 27155933, 21378394, 23469164, Balu[article]2024, 38896336, 8264597, 1581963, 1351188, 32914844) -
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at