rs267607557

Positions:

• chr1-156137182-T-A
• chr1-156137182-T-C
• chr1-156137182-T-G

Variant summary

Our verdict is Pathogenic. Variant got 17 ACMG points: 17P and 0B. PS1 PM1 PM2 PM5 PP2 PP3_Strong PP5_Moderate

The NM_170707.4(LMNA):​c.1558T>A​(p.Trp520Arg) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 13/22 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Another nucleotide change resulting in same amino acid change has been previously reported as Pathogenicin ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. W520G) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: LMNA NM_170707.4 missense
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 8.02

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 (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 17 ACMG points.

• PS1: Transcript NM_170707.4 (LMNA) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar as 476824
• PM1: In a hotspot region, there are 5 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 9 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 chr1-156137184-G-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 2734000.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), LMNA. . Gene score misZ 2.3673 (greater than the threshold 3.09). Trascript score misZ 3.0905 (greater than threshold 3.09). GenCC has associacion of gene with 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, 0.993
• PP5: Variant 1-156137182-T-A is Pathogenic according to our data. Variant chr1-156137182-T-A is described in ClinVar as [Pathogenic]. Clinvar id is 943114.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LMNA	NM_170707.4	c.1558T>A	p.Trp520Arg	missense_variant	9/12	ENST00000368300.9	NP_733821.1
LMNA	NM_005572.4	c.1558T>A	p.Trp520Arg	missense_variant	9/10	ENST00000677389.1	NP_005563.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LMNA	ENST00000368300.9	c.1558T>A	p.Trp520Arg	missense_variant	9/12	1	NM_170707.4	ENSP00000357283.4
LMNA	ENST00000677389.1	c.1558T>A	p.Trp520Arg	missense_variant	9/10		NM_005572.4	ENSP00000503633.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Charcot-Marie-Tooth disease type 2 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 02, 2019

This sequence change replaces tryptophan with arginine at codon 520 of the LMNA protein (p.Trp520Arg). The tryptophan residue is highly conserved and there is a moderate physicochemical difference between tryptophan and arginine. This variant disrupts the p.Trp520 amino acid residue in LMNA. Other variant(s) that disrupt this residue have been observed in individuals with LMNA-related conditions (PMID: 28688748, 10939567, 29211919), which suggests that this may be a clinically significant amino acid residue. For these reasons, this variant has been classified as Pathogenic. A different variant (c.1558T>C) giving rise to the same protein effect observed here (p.Trp520Arg) has been determined to be pathogenic (PMID: 25572245, 26098624,29211919, 29770364). This suggests that this variant is also likely to be causative of disease. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with LMNA-related conditions. This variant is not present in population databases (ExAC no frequency). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
CardioboostCm	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.59	D
BayesDel_noAF	Pathogenic	0.60
CADD	Pathogenic	28
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.99	.;.;D;.;.;.;.;D
Eigen	Pathogenic	0.83
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Pathogenic	0.97	D
LIST_S2	Benign	0.62	T;D;T;T;T;T;T;D
M_CAP	Pathogenic	0.85	D
MetaRNN	Pathogenic	0.99	D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.8	H;H;H;H;.;.;.;.
PrimateAI	Pathogenic	0.81	D
PROVEAN	Pathogenic	-13	D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.98
Sift	Uncertain	0.0060	D;D;D;D;D;D;D;D
Sift4G	Pathogenic	0.0	D;D;D;D;D;D;D;D
Polyphen		1.0	D;D;D;.;.;D;.;.
Vest4		0.95
MutPred		0.93		Gain of methylation at W520 (P = 0.0263);Gain of methylation at W520 (P = 0.0263);Gain of methylation at W520 (P = 0.0263);Gain of methylation at W520 (P = 0.0263);.;.;.;.;
MVP		0.98
MPC		1.5
ClinPred		1.0	D
GERP RS		4.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.99
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

Other links and lift over

dbSNP: rs267607557; hg19: chr1-156106973;