rs121908333
Variant summary
Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2PP5
The NM_001368067.1(LDB3):c.439G>A(p.Ala147Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,888 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. A147V) has been classified as Uncertain significance.
Frequency
Consequence
NM_001368067.1 missense
Scores
Clinical Significance
Conservation
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ACMG classification
Verdict is Uncertain_significance. Variant got 3 ACMG points.
Transcripts
RefSeq
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | MANE | UniProt |
---|---|---|---|---|---|---|---|
LDB3 | NM_001368067.1 | c.439G>A | p.Ala147Thr | missense_variant | 6/9 | ENST00000263066.11 | |
LDB3 | NM_007078.3 | c.690-4733G>A | intron_variant | ENST00000361373.9 |
Ensembl
Gene | Transcript | HGVSc | HGVSp | Effect | #exon/exons | TSL | MANE | Appris | UniProt |
---|---|---|---|---|---|---|---|---|---|
LDB3 | ENST00000263066.11 | c.439G>A | p.Ala147Thr | missense_variant | 6/9 | 1 | NM_001368067.1 | ||
LDB3 | ENST00000361373.9 | c.690-4733G>A | intron_variant | 1 | NM_007078.3 | P4 |
Frequencies
GnomAD3 genomes ? Cov.: 33
GnomAD4 exome AF: 6.84e-7 AC: 1AN: 1461888Hom.: 0 Cov.: 33 AF XY: 0.00 AC XY: 0AN XY: 727246
GnomAD4 genome ? Cov.: 33
ClinVar
Submissions by phenotype
Myofibrillar myopathy 4 Pathogenic:4
Pathogenic, no assertion criteria provided | literature only | OMIM | Feb 01, 2005 | - - |
Pathogenic, criteria provided, single submitter | clinical testing | Victorian Clinical Genetics Services, Murdoch Childrens Research Institute | Feb 02, 2022 | Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Pathogenic. Following criteria are met: 0102 - Loss of function is the proposed mechanism of disease in this gene and is associated with myofibrillar myopathy 4 (MIM#609452). (I) 0107 - This gene is associated with autosomal dominant disease. (I) 0200 - Variant is predicted to result in a missense amino acid change from alanine to threonine. (I) 0251 - This variant is heterozygous. (I) 0301 - Variant is absent from gnomAD (both v2 and v3). (SP) 0502 - Missense variant with conflicting in silico predictions and uninformative conservation. (I) 0604 - Variant is not located in an established domain, motif, hotspot or informative constraint region. (I) 0801 - This variant has strong previous evidence of pathogenicity in unrelated individuals. It has been reported in multiple unrelated individuals with myofibrillar myopathy (ClinVar, PMID: 18055494). (SP) 1208 - Inheritance information for this variant is not currently available in this individual. (I) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign - |
Likely pathogenic, criteria provided, single submitter | clinical testing | Molecular Genetics, Royal Melbourne Hospital | Aug 10, 2021 | This sequence change is predicted to replace alanine with threonine at codon 147 of the LDB3 protein (p.(Ala147Thr), also known as NM_007078.2:c.690-4733G>A). The alanine residue is evolutionarily conserved (100 vertebrates, UCSC), and is located in the striated muscle ZASP-like motif in exon 6 of the skeletal muscle isoform (PMID: 28349680). There is a small physicochemical difference between alanine and threonine. The variant is absent in a large population cohort (gnomAD v2.1 and v3.1). It has been identified in multiple individuals with myofibrillar myopathy, including variable cardiac and neuropathic involvement, and segregates with disease in at least one large family (PMID: 15668942, 18765652, 21676617, 23263837, 32721234). The variant demonstrates isoform-specific disruption of skeletal muscle actin filaments in functional assays (PMID: 24668811). Multiple lines of computational evidence have conflicting predictions for the missense substitution (3/4 algorithms predict benign). Based on the classification scheme RMH Modified ACMG Guidelines v1.4.0, this variant is classified as LIKELY PATHOGENIC. Following criteria are met: PS4_Moderate, PP1_Moderate, PS3_Supporting, PM2_Supporting. - |
Pathogenic, criteria provided, single submitter | clinical testing | Invitae | Jan 29, 2024 | This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 147 of the LDB3 protein (p.Ala147Thr). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with autosomal dominant myofibrillar myopathy (PMID: 15668942, 23263837). ClinVar contains an entry for this variant (Variation ID: 4727). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be tolerated. Experimental studies have shown that this missense change affects LDB3 function (PMID: 24668811). For these reasons, this variant has been classified as Pathogenic. - |
not provided Pathogenic:4
Pathogenic, criteria provided, single submitter | clinical testing | Athena Diagnostics | Apr 21, 2022 | This variant has not been reported in large, multi-ethnic general populations (http://gnomad.broadinstitute.org). This variant has been identified in multiple unrelated individuals with myofibrillar myopathy and appears to segregate with disease in at least one family. - |
Likely pathogenic, criteria provided, single submitter | clinical testing | Revvity Omics, Revvity | Mar 31, 2023 | - - |
Pathogenic, criteria provided, single submitter | clinical testing | GeneDx | Nov 19, 2020 | Published functional studies demonstrate disruption of the actin cytoskeleton in mouse muscle cells (Lin et. al., 2014); Not observed in large population cohorts (Lek et al., 2016); This variant is associated with the following publications: (PMID: 16427346, 32721234, 23263837, 15668942, 24668811, 18765652, no PMID, 19377068, 27546599, 28349680, 21676617) - |
Pathogenic, criteria provided, single submitter | clinical testing | CeGaT Center for Human Genetics Tuebingen | May 01, 2022 | LDB3: PP1:Strong, PM2, PS4:Moderate, PP3, PS3:Supporting - |
Cardiomyopathy Uncertain:1
Uncertain significance, criteria provided, single submitter | clinical testing | CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario | Apr 21, 2020 | - - |
Dilated cardiomyopathy 1C;C4721886:Myofibrillar myopathy 4 Other:1
not provided, no classification provided | phenotyping only | GenomeConnect - Invitae Patient Insights Network | - | Variant interpreted as Pathogenic and reported on 05-08-2018 by Lab Invitae. GenomeConnect-Invitae Patient Insights Network assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. Registry team members make no attempt to reinterpret the clinical significance of the variant. Phenotypic details are available under supporting information. - |
Computational scores
Source:
Splicing
Find out detailed SpliceAI scores and Pangolin per-transcript scores at