rs755686359

Variant names:

• chr1-156136311-C-T
• rs755686359
• NM_170707.4:c.1255C>T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PP3_Moderate

The NM_170707.4(LMNA):​c.1255C>T​(p.Arg419Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000105 in 1,612,146 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. R419L) has been classified as Uncertain significance.

• Frequency:
  • Genomes: 𝑓 0.000033 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000082 (0 hom.)
• Consequence: LMNA NM_170707.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5 B:1
• Conservation: PhyloP100: 2.35
• Publications: 9 publications found

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 Gene-Disease associations (from GenCC):

• dilated cardiomyopathy

  Inheritance: AD Classification: DEFINITIVE Submitted by: ClinGen
• dilated cardiomyopathy 1A

  Inheritance: AD Classification: DEFINITIVE, SUPPORTIVE Submitted by: G2P, Ambry Genetics, Orphanet
• familial partial lipodystrophy, Dunnigan type

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp, G2P, Labcorp Genetics (formerly Invitae)
• Hutchinson-Gilford progeria syndrome

  Inheritance: AD, SD Classification: DEFINITIVE, STRONG, MODERATE, SUPPORTIVE Submitted by: Orphanet, G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae)
• restrictive dermopathy 2

  Inheritance: AR, AD Classification: DEFINITIVE, LIMITED Submitted by: G2P
• Emery-Dreifuss muscular dystrophy 2, autosomal dominant

  Inheritance: SD, AD Classification: DEFINITIVE, STRONG Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
• atrioventricular block

  Inheritance: AD Classification: STRONG Submitted by: Genomics England PanelApp
• heart-hand syndrome, Slovenian type

  Inheritance: AD Classification: STRONG, MODERATE, SUPPORTIVE, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Orphanet, Ambry Genetics, G2P
• Charcot-Marie-Tooth disease type 2B1

  Inheritance: AR, AD Classification: STRONG, MODERATE, SUPPORTIVE, LIMITED Submitted by: G2P, Ambry Genetics, Orphanet, Labcorp Genetics (formerly Invitae)
• Emery-Dreifuss muscular dystrophy 3, autosomal recessive

  Inheritance: AR Classification: STRONG Submitted by: Labcorp Genetics (formerly Invitae)
• mandibuloacral dysplasia with type A lipodystrophy

  Inheritance: AR Classification: STRONG, SUPPORTIVE Submitted by: Labcorp Genetics (formerly Invitae), Orphanet
• atrial fibrillation

  Inheritance: AD Classification: MODERATE Submitted by: Ambry Genetics
• atypical Werner syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• autosomal dominant Emery-Dreifuss muscular dystrophy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• congenital muscular dystrophy due to LMNA mutation

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial isolated dilated cardiomyopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• lethal restrictive dermopathy

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• LMNA-related cardiocutaneous progeria syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• autosomal recessive Emery-Dreifuss muscular dystrophy

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• dilated cardiomyopathy-hypergonadotropic hypogonadism syndrome

  Inheritance: AR Classification: SUPPORTIVE Submitted by: Orphanet
• autosomal semi-dominant severe lipodystrophic laminopathy

  Inheritance: SD Classification: SUPPORTIVE Submitted by: Orphanet
• arrhythmogenic right ventricular cardiomyopathy

  Inheritance: AD Classification: LIMITED Submitted by: ClinGen

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PP3: MetaRNN computational evidence supports a deleterious effect, 0.844

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LMNA	NM_170707.4	c.1255C>T	p.Arg419Cys	missense_variant	Exon 7 of 12	ENST00000368300.9	NP_733821.1
LMNA	NM_005572.4	c.1255C>T	p.Arg419Cys	missense_variant	Exon 7 of 10	ENST00000677389.1	NP_005563.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LMNA	ENST00000368300.9	c.1255C>T	p.Arg419Cys	missense_variant	Exon 7 of 12	1	NM_170707.4	ENSP00000357283.4
LMNA	ENST00000677389.1	c.1255C>T	p.Arg419Cys	missense_variant	Exon 7 of 10		NM_005572.4	ENSP00000503633.1

Frequencies

GnomAD3 genomes AF: 0.0000329 AC: 5 AN: 152206 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.0000241

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000588

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.0000160 AC: 4 AN: 250618 AF XY: 0.0000148

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000264

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000822 AC: 12 AN: 1459940 Hom.: 0 Cov.: 34 AF XY: 0.00000826 AC XY: 6 AN XY: 726308

African (AFR) AF: 0.00 AC: 0 AN: 33436

American (AMR) AF: 0.00 AC: 0 AN: 44724

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26136

East Asian (EAS) AF: 0.00 AC: 0 AN: 39700

South Asian (SAS) AF: 0.0000116 AC: 1 AN: 86188

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52866

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4632

European-Non Finnish (NFE) AF: 0.00000989 AC: 11 AN: 1111996

Other (OTH) AF: 0.00 AC: 0 AN: 60262

GnomAD4 genome AF: 0.0000329 AC: 5 AN: 152206 Hom.: 0 Cov.: 32 AF XY: 0.0000269 AC XY: 2 AN XY: 74352

African (AFR) AF: 0.0000241 AC: 1 AN: 41464

American (AMR) AF: 0.00 AC: 0 AN: 15270

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3472

East Asian (EAS) AF: 0.00 AC: 0 AN: 5186

South Asian (SAS) AF: 0.00 AC: 0 AN: 4832

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10624

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 316

European-Non Finnish (NFE) AF: 0.0000588 AC: 4 AN: 68038

Other (OTH) AF: 0.00 AC: 0 AN: 2092

Alfa AF: 0.0000213 Hom.: 0

Bravo AF: 0.0000340

ExAC AF: 0.00000824 AC: 1

EpiCase AF: 0.000109

EpiControl AF: 0.00

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Cardiomyopathy Uncertain:1

Dec 07, 2022

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 cysteine at codon 419 of the lamin A/C proteins. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). Functional studies have shown that this variant may affect localization and binding affinity of the lamin A/C protein (PMID: 23977161, 24943589). This variant has been reported in three individuals from a single family affected with partial lipodystrophy and diabetes (PMID: 12716787). It has also been reported in an individual affected with arrhythmogenic right ventricular cardiomyopathy (PMID: 30847666). This variant has been identified in 6/282010 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. -

not provided Uncertain:1

Dec 21, 2016

Eurofins Ntd Llc (ga)

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Primary dilated cardiomyopathy Uncertain:1

Aug 29, 2024

All of Us Research Program, National Institutes of Health

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This missense variant replaces arginine with cysteine at codon 419 of the lamin A/C proteins. Computational prediction is inconclusive regarding the impact of this variant on protein structure and function (internally defined REVEL score threshold 0.5 < inconclusive < 0.7, PMID: 27666373). Functional studies have shown that this variant may affect localization and binding affinity of the lamin A/C protein (PMID: 23977161, 24943589). This variant has been reported in three individuals from a single family affected with partial lipodystrophy and diabetes (PMID: 12716787). It has also been reported in an individual affected with arrhythmogenic right ventricular cardiomyopathy (PMID: 30847666). This variant has been identified in 6/282010 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. -

Hutchinson-Gilford syndrome;C0410190:Emery-Dreifuss muscular dystrophy 2, autosomal dominant;C0796031:Dilated cardiomyopathy-hypergonadotropic hypogonadism syndrome;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;C5979868:Dilated cardiomyopathy 1A Uncertain:1

Feb 16, 2022

Fulgent Genetics, Fulgent Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Cardiovascular phenotype Uncertain:1

Nov 22, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R419C variant (also known as c.1255C>T), located in coding exon 7 of the LMNA gene, results from a C to T substitution at nucleotide position 1255. The arginine at codon 419 is replaced by cysteine, an amino acid with highly dissimilar properties. This variant has been reported in a family with familial partial lipodystrophy, and has been detected in an individual reported to have limb girdle muscular dystrophy (Haque WA et al. Diabetes Care, 2003 May;26:1350-5; Nishikawa A et al. J Med Genet, 2017 Feb;54:104-110). Functional studies indicate this variant may impact protein function (Kiel T et al. Int J Biochem Cell Biol, 2014 Aug;53:271-80). 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

Nov 13, 2024

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	0.82
CardioboostCm	Uncertain	0.65
BayesDel_addAF	Pathogenic	0.40	D
BayesDel_noAF	Pathogenic	0.44
CADD	Pathogenic	30
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.92	.;.;.;D;.;.;.;.;T
Eigen	Uncertain	0.52
Eigen_PC	Uncertain	0.56
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.97	D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.83	D
MetaRNN	Pathogenic	0.84	D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Uncertain	2.4	M;.;M;M;M;.;.;.;.
PhyloP100		2.4
PrimateAI	Uncertain	0.66	T
PROVEAN	Pathogenic	-4.7	D;D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.67
Sift	Uncertain	0.0010	D;D;D;D;D;D;D;D;D
Sift4G	Uncertain	0.0030	D;D;D;D;D;D;D;D;D
Polyphen		1.0	D;.;D;D;.;.;D;.;.
Vest4		0.68
MutPred		0.42		Gain of methylation at K418 (P = 0.0215);Gain of methylation at K418 (P = 0.0215);Gain of methylation at K418 (P = 0.0215);Gain of methylation at K418 (P = 0.0215);Gain of methylation at K418 (P = 0.0215);.;.;.;.;
MVP		0.96
MPC		1.3
ClinPred		0.97	D
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.9
Varity_R		0.47
gMVP		0.92
Mutation Taster		=0/100	disease causing

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

Other links and lift over

dbSNP: rs755686359; hg19: chr1-156106102;