rs61295588

Positions:

• chr1-156134809-T-C

Variant summary

Our verdict is Pathogenic. Variant got 17 ACMG points: 17P and 0B. PM1 PM2 PP2 PP3_Strong PP5_Very_Strong

The NM_170707.4(LMNA):​c.644T>C​(p.Leu215Pro) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L215V) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: LMNA NM_170707.4 missense
• Clinical Significance: Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:2 O:2
• Conservation: PhyloP100: 6.20

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]

ACMG classification

Verdict is Pathogenic. Variant got 17 ACMG points.

• PM1: In a hotspot region, there are 4 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
• PP2: Missense variant where missense usually causes diseases, LMNA
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.983
• PP5: Variant 1-156134809-T-C is Pathogenic according to our data. Variant chr1-156134809-T-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 65764.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr1-156134809-T-C is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LMNA	NM_170707.4	c.644T>C	p.Leu215Pro	missense_variant	4/12	ENST00000368300.9
LMNA	NM_005572.4	c.644T>C	p.Leu215Pro	missense_variant	4/10	ENST00000677389.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LMNA	ENST00000368300.9	c.644T>C	p.Leu215Pro	missense_variant	4/12	1	NM_170707.4	P1
LMNA	ENST00000677389.1	c.644T>C	p.Leu215Pro	missense_variant	4/10		NM_005572.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

Alfa AF: 0.00152 Hom.: 0

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2 Other:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Charcot-Marie-Tooth disease type 2 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Jun 22, 2023

For these reasons, this variant has been classified as Pathogenic. Experimental studies have shown that this missense change affects LMNA function (PMID: 20160190). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is expected to disrupt LMNA protein function. ClinVar contains an entry for this variant (Variation ID: 65764). This missense change has been observed in individual(s) with conduction disease and/or dilated cardiomyopathy (PMID: 12486434). It has also been observed to segregate with disease in related individuals. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces leucine, which is neutral and non-polar, with proline, which is neutral and non-polar, at codon 215 of the LMNA protein (p.Leu215Pro). -

Cardiovascular phenotype Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

May 11, 2021

The p.L215P variant (also known as c.644T>C), located in coding exon 4 of the LMNA gene, results from a T to C substitution at nucleotide position 644. The leucine at codon 215 is replaced by proline, an amino acid with similar properties. This alteration has been detected in a family with cardiac conduction defects and dilated cardiomyopathy (DCM), showing segregation within the family (Hershberger RE et al. Am Heart J, 2002 Dec;144:1081-6). Based on internal structural analysis, this variant is anticipated to result in a significant decrease in structural stability (Bunick CG et al. J Invest Dermatol, 2017 01;137:142-150). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). This amino acid position is well conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

not provided Other:1

not provided, no classification provided

literature only

Epithelial Biology; Institute of Medical Biology, Singapore

-

- -

Dilated cardiomyopathy 1A Other:1

not provided, no classification provided

literature only

GeneReviews

-

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
CardioboostCm	Uncertain	0.83
BayesDel_addAF	Pathogenic	0.47	D
BayesDel_noAF	Pathogenic	0.44
CADD	Pathogenic	31
DANN	Uncertain	1.0
Eigen	Pathogenic	0.79
Eigen_PC	Pathogenic	0.72
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.94	D;D;D;D;D;D;D;D;D
M_CAP	Pathogenic	0.85	D
MetaRNN	Pathogenic	0.98	D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.94	D
MutationAssessor	Pathogenic	3.8	H;.;H;H;H;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D
PrimateAI	Pathogenic	0.87	D
PROVEAN	Uncertain	-4.3	D;D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.91
Sift	Uncertain	0.0010	D;D;D;D;D;D;D;D;D
Sift4G	Pathogenic	0.0010	D;D;D;D;D;D;D;D;D
Polyphen		1.0	D;.;D;D;.;.;D;.;.
Vest4		0.94
MutPred		0.90		Loss of stability (P = 0.0134);Loss of stability (P = 0.0134);Loss of stability (P = 0.0134);Loss of stability (P = 0.0134);Loss of stability (P = 0.0134);.;.;.;.;
MVP		0.98
MPC		2.6
ClinPred		0.99	D
GERP RS		5.3
RBP_binding_hub_radar		1.0
RBP_regulation_power_radar		4.0
Varity_R		0.92
gMVP		1.0

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: rs61295588; hg19: chr1-156104600; COSMIC: COSV100738907; COSMIC: COSV100738907;