1-156114992-G-T

Variant names:

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1PM2PM5PP2PP3

The NM_170707.4(LMNA):c.74G>T(p.Arg25Leu) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.0000163 in 1,598,306 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. R25C) has been classified as Likely pathogenic.

Frequency

Genomes: 𝑓 0.000026 ( 0 hom., cov: 32)

Exomes 𝑓: 0.000015 ( 0 hom. )

Consequence

LMNA
NM_170707.4 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:6B:1

Conservation

PhyloP100: 7.99

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]

LMNA links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

PM1

In a hotspot region, there are 7 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 12 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 chr1-156114991-C-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 66929.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

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

MetaRNN computational evidence supports a deleterious effect, 0.813

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LMNA	NM_170707.4 link	c.74G>T	p.Arg25Leu	missense_variant	Exon 1 of 12	ENST00000368300.9	NP_733821.1	P02545-1A0A384MQX1
LMNA	NM_005572.4 link	c.74G>T	p.Arg25Leu	missense_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
LMNA	ENST00000368300.9 link	c.74G>T	p.Arg25Leu	missense_variant	Exon 1 of 12	1	NM_170707.4	ENSP00000357283.4		P02545-1
LMNA	ENST00000677389.1 link	c.74G>T	p.Arg25Leu	missense_variant	Exon 1 of 10		NM_005572.4	ENSP00000503633.1		P02545-2

Frequencies

GnomAD3 genomes

AF:

0.0000263

AC:

AN:

152202

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.000576

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000543

AC:

AN:

220954

Hom.:

AF XY:

0.0000751

AC XY:

AN XY:

119854

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00106

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000205

Gnomad OTH exome

AF:

0.00

GnomAD4 exome

AF:

0.0000152

AC:

AN:

1446104

Hom.:

Cov.:

AF XY:

0.0000181

AC XY:

AN XY:

717908

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.000621

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00000272

Gnomad4 OTH exome

AF:

0.0000503

GnomAD4 genome

AF:

0.0000263

AC:

AN:

152202

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74360

show subpopulations

Gnomad4 AFR

AF:

0.00

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.000576

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.0000294

Gnomad4 OTH

AF:

0.00

Alfa

AF:

0.000130

Hom.:

Bravo

AF:

0.0000151

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:6Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Jan 01, 2024

CeGaT Center for Human Genetics Tuebingen

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

LMNA: PM2, PM5, PP3 -

Jan 15, 2019

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The R25L variant of uncertain significance in the LMNA gene has not been published as a pathogenic variant or been reported as a benign variant to our knowledge. This variant was not observed in approximately 6,500 individuals of European and African American ancestry in the NHLBI Exome Sequencing Project, indicating it is not a common benign variant in these populations. The R25L variant is a non-conservative amino acid substitution, which is likely to impact secondary protein structure as these residues differ in polarity, charge, size and/or other properties. Additionally, this substitution occurs at a position that is conserved across species. Consequently, in silico analysis predicts this variant is probably damaging to the protein structure/function. Missense variants in this residue (R25G, R25C, R25P) and missense variants in nearby residues (S22L, T27I, T27S, R28W, R28Q) have been reported in the Human Gene Mutation Database in association with LMNA-related disorders (Stenson et al., 2014), supporting the functional importance of this region of the protein. -

Cardiomyopathy

Uncertain:1

Apr 28, 2023

Color Diagnostics, LLC DBA Color Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces arginine with leucine at codon 25 of the LMNA protein. Computational prediction suggests that this variant may have a deleterious impact on protein structure and function (internally defined REVEL score threshold >= 0.7, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in two individuals affected with conduction defects (PMID: 31383942). It has also been reported in two individuals affected with familial partial lipodystrophy type 2 (PMID: 30418556, 36397776). This variant has been identified in 14/252328 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Primary dilated cardiomyopathy

Uncertain:1

Jul 29, 2024

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Hutchinson-Gilford syndrome;C0410190:Emery-Dreifuss muscular dystrophy 2, autosomal dominant;C0796031:Dilated cardiomyopathy-hypergonadotropic hypogonadism syndrome;C1449563:Dilated cardiomyopathy 1A;C1720860:Familial partial lipodystrophy, Dunnigan type;C1854154:Charcot-Marie-Tooth disease type 2B1;C1857829:Heart-hand syndrome, Slovenian type;C2750035:Emery-Dreifuss muscular dystrophy 3, autosomal recessive;C2750785:Congenital muscular dystrophy due to LMNA mutation;C5399785:Mandibuloacral dysplasia with type A lipodystrophy;C5676942:Restrictive dermopathy 2

Uncertain:1

Mar 08, 2024

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Cardiovascular phenotype

Uncertain:1

Dec 20, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R25L variant (also known as c.74G>T), located in coding exon 1 of the LMNA gene, results from a G to T substitution at nucleotide position 74. The arginine at codon 25 is replaced by leucine, an amino acid with dissimilar properties. This variant was reported in individual(s) with features consistent with laminopathies (Patni N et al. J Clin Endocrinol Metab, 2019 04;104:1099-1108; Park J et al. Genet Med. 2020 Jan;22(1):102-111; Vasandani C et al. J Endocr Soc. 2022 Oct;6(12):bvac155). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Charcot-Marie-Tooth disease type 2

Benign:1

Jan 29, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Pathogenic

0.95

CardioboostCm

Pathogenic

1.0

BayesDel_addAF

Pathogenic

0.44

BayesDel_noAF

Pathogenic

0.39

CADD

Pathogenic

DANN

Uncertain

1.0

DEOGEN2

Pathogenic

0.88

.;.;.;D;.

Eigen

Uncertain

0.62

Eigen_PC

Uncertain

0.65

FATHMM_MKL

Pathogenic

0.99

LIST_S2

Uncertain

0.96

D;D;D;D;D

M_CAP

Pathogenic

0.72

MetaRNN

Pathogenic

0.81

D;D;D;D;D

MetaSVM

Uncertain

0.29

MutationAssessor

Uncertain

2.1

M;.;M;M;M

PrimateAI

Pathogenic

0.87

PROVEAN

Pathogenic

-5.8

D;D;D;D;D

REVEL

Pathogenic

0.87

Sift

Uncertain

0.0020

D;D;D;D;D

Sift4G

Uncertain

0.0070

D;D;D;D;D

Polyphen

0.97

D;.;P;P;.

Vest4

0.92

MutPred

0.62

Loss of MoRF binding (P = 0.0142);Loss of MoRF binding (P = 0.0142);Loss of MoRF binding (P = 0.0142);Loss of MoRF binding (P = 0.0142);Loss of MoRF binding (P = 0.0142);

MVP

0.99

MPC

1.3

ClinPred

0.94

GERP RS

4.8

RBP_binding_hub_radar

0.0

RBP_regulation_power_radar

1.9

Varity_R

0.86

gMVP

0.99

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