NM_001368067.1:c.439G>A

Variant names:

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM2PP5_Very_Strong

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 Likely pathogenic (★★).

Frequency

Genomes: not found (cov: 33)

Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

LDB3
NM_001368067.1 missense

Scores

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:10O:1

Conservation

PhyloP100: 10.0

Variant links:

Genes affected

LDB3 (HGNC:15710): (LIM domain binding 3) This gene encodes a PDZ domain-containing protein. PDZ motifs are modular protein-protein interaction domains consisting of 80-120 amino acid residues. PDZ domain-containing proteins interact with each other in cytoskeletal assembly or with other proteins involved in targeting and clustering of membrane proteins. The protein encoded by this gene interacts with alpha-actinin-2 through its N-terminal PDZ domain and with protein kinase C via its C-terminal LIM domains. The LIM domain is a cysteine-rich motif defined by 50-60 amino acids containing two zinc-binding modules. This protein also interacts with all three members of the myozenin family. Mutations in this gene have been associated with myofibrillar myopathy and dilated cardiomyopathy. Alternatively spliced transcript variants encoding different isoforms have been identified; all isoforms have N-terminal PDZ domains while only longer isoforms (1, 2 and 5) have C-terminal LIM domains. [provided by RefSeq, Jan 2010]

LDB3 links:

ENSG00000289258 (HGNC:):

ENSG00000289258 links:

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 10 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 10-86687163-G-A is Pathogenic according to our data. Variant chr10-86687163-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 4727.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr10-86687163-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LDB3	NM_001368067.1 link	c.439G>A	p.Ala147Thr	missense_variant	Exon 6 of 9	ENST00000263066.11	NP_001354996.1
LDB3	NM_007078.3 link	c.690-4733G>A		intron_variant	Intron 5 of 13	ENST00000361373.9	NP_009009.1	O75112-1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	UniProt
LDB3	ENST00000263066.11 link	c.439G>A	p.Ala147Thr	missense_variant	Exon 6 of 9	1	NM_001368067.1	ENSP00000263066.7	O75112-6
LDB3	ENST00000361373.9 link	c.690-4733G>A		intron_variant	Intron 5 of 13	1	NM_007078.3	ENSP00000355296.3	O75112-1
ENSG00000289258	ENST00000443292.2 link	c.2199-4733G>A		intron_variant	Intron 15 of 17	1		ENSP00000393132.2	C9JWU6

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.84e-7

AC:

AN:

1461888

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

727246

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

8.99e-7

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:10Other:1

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Myofibrillar myopathy 4

Pathogenic:4

Aug 10, 2021

Molecular Genetics, Royal Melbourne Hospital

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. -

Feb 01, 2005

OMIM

Significance: Pathogenic

Review Status: no assertion criteria provided

Collection Method: literature only

- -

Feb 02, 2022

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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 -

Sep 30, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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

Nov 19, 2020

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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) -

Oct 31, 2024

Athena Diagnostics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

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. -

May 01, 2022

CeGaT Center for Human Genetics Tuebingen

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

LDB3: PP1:Strong, PM2, PS4:Moderate, PP3, PS3:Supporting -

Mar 31, 2023

Revvity Omics, Revvity

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Dilated cardiomyopathy 1C;C4721886:Myofibrillar myopathy 4

Pathogenic:1Other:1

Apr 11, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

GenomeConnect - Invitae Patient Insights Network

Significance: not provided

Review Status: no classification provided

Collection Method: phenotyping only

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. -

Cardiomyopathy

Pathogenic:1

Sep 25, 2024

CHEO Genetics Diagnostic Laboratory, Children's Hospital of Eastern Ontario

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has also been referred to as p.Ala147Thr using alternate transcripts, and reported using the historical gene name, ZASP. The c.690-4733G nucleotide is highly conserved. It has not been reported in control populations in the Genome Aggregation Database (gnomAD). It has been previously reported in at >5 apparently unrelated individuals with myofibrillar myopathy (MFM) (PMID 15668942, 18765652, 23263837, 21676617) and is considered to be one of the most common MFM-related LDB3 variants (PMID 33802723). This variant was reported to segregate with disease in 1 family (PMID 15668942). Functional studies showed conflicting results for this variant. One study demonstrated significant biological impact for this variant in relation to myofibrillar myopathy: this variant disrupted the actin cytoskeleton in transfected mouse muscle cells (PMID 24668811). However, another functional study demonstrated that this variant does not impact binding to phosphoglucomutase I, which is thought to be the mechanism of LDB3 involvement in dilated cardiomyopathy (PMID 19377068). In silico splicing analyses do not predict the c.690-4733G>A variant to have a significant effect on splicing. However, this prediction has not been confirmed by RNA functional studies. This variant is listed in ClinVar (VCV000004727). Based on the above evidence, we classify this variant as likely pathogenic for myofibrillar myopathy, which, in rare cases, could also produce cardiomyopathy. -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.30

BayesDel_noAF

Pathogenic

0.19

CADD

Benign

DANN

Pathogenic

1.0

Eigen

Uncertain

0.51

Eigen_PC

Uncertain

0.57

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Pathogenic

0.98

D;.;D;D;D

M_CAP

Benign

0.084

MetaRNN

Uncertain

0.73

D;D;D;D;D

MetaSVM

Uncertain

0.46

PROVEAN

Benign

-1.2

N;.;N;N;N

REVEL

Pathogenic

0.67

Sift

Uncertain

0.019

D;.;T;D;D

Sift4G

Benign

0.53

T;T;T;T;T

Polyphen

0.065, 1.0, 1.0

.;.;B;D;D

Vest4

0.75

MutPred

0.46

.;.;Gain of ubiquitination at K146 (P = 0.0762);.;Gain of ubiquitination at K146 (P = 0.0762);

MVP

0.87

MPC

0.72

ClinPred

0.93

GERP RS

5.0

gMVP

0.92

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.

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