1-156115274-G-C

Variant summary

Our verdict is Pathogenic. Variant got 11 ACMG points: 11P and 0B. PM1PM2PM5PP2PP3_Strong

The NM_170707.4(LMNA):​c.356G>C​(p.Arg119Pro) variant causes a missense, splice region change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 2/3 splice prediction tools predicting alterations to normal splicing. 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. R119C) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)

Consequence

LMNA
NM_170707.4 missense, splice_region

Scores

11
8
1
Splicing: ADA: 0.9999
2

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:2U:3

Conservation

PhyloP100: 5.89
Variant links:
Genes affected
LMNA (HGNC:6636): (lamin A/C) The protein encoded by this gene is part of the nuclear lamina, a two-dimensional matrix of proteins located next to the inner nuclear membrane. The lamin family of proteins make up the matrix and are highly conserved in evolution. During mitosis, the lamina matrix is reversibly disassembled as the lamin proteins are phosphorylated. Lamin proteins are thought to be involved in nuclear stability, chromatin structure and gene expression. Vertebrate lamins consist of two types, A and B. Alternative splicing results in multiple transcript variants. Mutations in this gene lead to several diseases: Emery-Dreifuss muscular dystrophy, familial partial lipodystrophy, limb girdle muscular dystrophy, dilated cardiomyopathy, Charcot-Marie-Tooth disease, and Hutchinson-Gilford progeria syndrome. [provided by RefSeq, May 2022]

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ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 11 ACMG points.

PM1
In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 16 uncertain in NM_170707.4
PM2
Very rare variant in population databases, with high coverage;
PM5
Other missense variant is known to change same aminoacid residue: Variant chr1-156115274-G-A is described in Lovd as [Likely_pathogenic].
PP2
Missense variant in the LMNA gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 178 curated pathogenic missense variants (we use a threshold of 10). The gene has 69 curated benign missense variants. Gene score misZ: 2.3673 (below the threshold of 3.09). Trascript score misZ: 3.0905 (above the threshold of 3.09). GenCC associations: The gene is linked to familial partial lipodystrophy, Dunnigan type, autosomal recessive Emery-Dreifuss muscular dystrophy, LMNA-related cardiocutaneous progeria syndrome, atrioventricular block, dilated cardiomyopathy 1A, Emery-Dreifuss muscular dystrophy 2, autosomal dominant, atypical Werner syndrome, restrictive dermopathy 1, autosomal semi-dominant severe lipodystrophic laminopathy, Emery-Dreifuss muscular dystrophy 3, autosomal recessive, dilated cardiomyopathy, Charcot-Marie-Tooth disease type 2B1, dilated cardiomyopathy-hypergonadotropic hypogonadism syndrome, arrhythmogenic right ventricular cardiomyopathy, familial isolated dilated cardiomyopathy, mandibuloacral dysplasia with type A lipodystrophy, autosomal dominant Emery-Dreifuss muscular dystrophy, heart-hand syndrome, Slovenian type, congenital muscular dystrophy due to LMNA mutation, lethal restrictive dermopathy, Hutchinson-Gilford progeria syndrome.
PP3
Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF. Scorers claiming Uncertain: max_spliceai. No scorers claiming Benign.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
LMNANM_170707.4 linkc.356G>C p.Arg119Pro missense_variant, splice_region_variant Exon 1 of 12 ENST00000368300.9 NP_733821.1 P02545-1A0A384MQX1
LMNANM_005572.4 linkc.356G>C p.Arg119Pro missense_variant, splice_region_variant Exon 1 of 10 ENST00000677389.1 NP_005563.1 P02545-2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
LMNAENST00000368300.9 linkc.356G>C p.Arg119Pro missense_variant, splice_region_variant Exon 1 of 12 1 NM_170707.4 ENSP00000357283.4 P02545-1
LMNAENST00000677389.1 linkc.356G>C p.Arg119Pro missense_variant, splice_region_variant Exon 1 of 10 NM_005572.4 ENSP00000503633.1 P02545-2

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
Cov.:
31
GnomAD4 genome
Cov.:
32

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Pathogenic:2Uncertain:3
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

not provided Pathogenic:2
Jan 09, 2025
GeneDx
Significance: Likely pathogenic
Review Status: criteria provided, single submitter
Collection Method: clinical testing

Reported in association with dilated cardiomyopathy; however, additional clinical information was not provided (PMID: 27532257, 24503780); Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; In silico analysis suggests this variant may impact gene splicing. In the absence of RNA/functional studies, the actual effect of this sequence change is unknown.; This variant is associated with the following publications: (PMID: 27532257, 28679633, 34461741, 37652022, 38979608, 36548481, 24503780, 10939567) -

Dec 15, 2017
Stanford Center for Inherited Cardiovascular Disease, Stanford University
Significance: Likely pathogenic
Review Status: no assertion criteria provided
Collection Method: provider interpretation

We identified this variant in a patient with dilated cardiomyopathy and limb girdle muscular dystrophy. SCICD Classification: likely pathogenic variant based on absence in the general population, moderate case data, moderate segregation and position of variant. We do feel it is suitable for assessing risk in healthy relatives ("predictive genetic testing"), however family members should be counseled about probabilistic nature of genetic testing. Additional case data or segregation could provide additional evidence towards pathogenicity. Gene-level evidence: LMNA: Pathogenic variants in LMNA cause clinically variable diseases, called the laminopathies. These include dilated cardiomyopathy (DCM), which is typically accompanied by conduction system disease and/or arrhythmias. Sudden cardiac death can occur before the onset of LV dilation, warranting early consideration of an ICD. Other laminopathies include Emery-Dreifuss muscular dystrophy, Hutchinson-Gilford progeria syndrome and lipodystrophies, among others. Region-level evidence: according to Amr et al 2016, this variant falls within the filament domain, a region that is greatly enriched for intolerance to variant in cases vs. controls (OR: 152). Case data (not including our patient): 3 · I contacted Gene Dx and they reported they have seen the variant in 2 probands (one who harbored additional variants) who had cardiomyopathy panels. LMM has seen it in 1 patient and it overlaps with that reported by Pugh 2014. · Cases in the literature: 1 (redudant with lab data_ ? Pugh 2014: reported in 44yo woman with clinical dx of DCM with VF and family history of arrhythmia and sudden death. Classified as likely pathogenic. No other disease causing variants reported. Segregation data: To our knowledge, clnical colleagues at a different institution have seen this variant in a family where it segregates in 4 affected family members (may overlap with cases reported by genetic testing laboratories. Our patient's affected brother was apparently tested and was positive. Functional data: None reported In silico data (missense variants only): Per various prediction models in varsome.com, the variant is disease causing/deleterious. Of note, the variant does alter the last amino acid at the exon/intron junction, which could possible affect splicing. Nearby pathogenic variants at this codon or neighboring codons: A different variant at the same position (c.354_355delGCinsAG; p.Arg119Gly) is listed as likely pathogenic in ClinVar by Blueprint. No summary evidence provided. Population data: Absent The variant is absent from the Genome Aggregation Consortium Dataset (gnomAD; http://gnomad.broadinstitute.org/), which currently includes variant calls on >140,000 unrelated individuals of African, Asian, European, Latino, and Ashkenazi descent. Per Varsome.org, the average coverage at that site in genomes is 33x whereas in exomes it is 60x. -

not specified Uncertain:2
Aug 20, 2014
Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

proposed classification - variant undergoing re-assessment, contact laboratory -

Sep 06, 2016
Athena Diagnostics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Charcot-Marie-Tooth disease type 2 Uncertain:1
Jan 21, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This sequence change replaces arginine, which is basic and polar, with proline, which is neutral and non-polar, at codon 119 of the LMNA protein (p.Arg119Pro). This variant also falls at the last nucleotide of exon 1, which is part of the consensus splice site for this exon. This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with arrhythmogenic cardiomyopathy and/or dilated cardiomyopathy (PMID: 24503780, 27532257, 36548481). ClinVar contains an entry for this variant (Variation ID: 48064). 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 disruptive. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this missense change is associated with inconclusive levels of altered splicing (PMID: 28679633). 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Pathogenic
1.0
CardioboostCm
Uncertain
0.73
BayesDel_addAF
Pathogenic
0.46
D
BayesDel_noAF
Pathogenic
0.42
CADD
Pathogenic
37
DANN
Uncertain
1.0
DEOGEN2
Pathogenic
0.97
.;.;.;D;.
Eigen
Pathogenic
0.81
Eigen_PC
Pathogenic
0.73
FATHMM_MKL
Pathogenic
0.99
D
LIST_S2
Uncertain
0.94
D;D;D;D;D
M_CAP
Pathogenic
0.72
D
MetaRNN
Pathogenic
0.92
D;D;D;D;D
MetaSVM
Uncertain
0.77
D
MutationAssessor
Pathogenic
3.6
H;.;H;H;H
PrimateAI
Uncertain
0.78
T
PROVEAN
Uncertain
-3.4
D;D;D;D;D
REVEL
Pathogenic
0.87
Sift
Uncertain
0.014
D;D;D;D;D
Sift4G
Uncertain
0.029
D;D;D;D;D
Polyphen
1.0
D;.;D;D;.
Vest4
0.88
MutPred
0.70
Loss of MoRF binding (P = 3e-04);Loss of MoRF binding (P = 3e-04);Loss of MoRF binding (P = 3e-04);Loss of MoRF binding (P = 3e-04);Loss of MoRF binding (P = 3e-04);
MVP
0.96
MPC
2.5
ClinPred
0.99
D
GERP RS
4.0
RBP_binding_hub_radar
0.67
RBP_regulation_power_radar
3.5
Varity_R
0.98
gMVP
0.98

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Pathogenic
1.0
dbscSNV1_RF
Pathogenic
0.95
SpliceAI score (max)
0.47
Details are displayed if max score is > 0.2
DS_DG_spliceai
0.47
Position offset: -32

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.

Other links and lift over

dbSNP: rs397517902; hg19: chr1-156085065; API