NM_170707.4:c.94A>G

Variant names:

• chr1-156115012-A-G
• rs1553261891
• NM_170707.4:c.94A>G

Variant summary

Our verdict is Pathogenic. Variant got 17 ACMG points: 17P and 0B. PM1 PM2 PM5 PP2 PP3_Moderate PP5_Very_Strong

The NM_170707.4(LMNA):​c.94A>G​(p.Lys32Glu) 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. 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. K32T) has been classified as Pathogenic.

• 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
• Conservation: PhyloP100: 7.32

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 9 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 15 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 chr1-156115013-A-C is described in ClinVar as [Pathogenic]. Clinvar id is 2503449.Status of the report is no_assertion_criteria_provided, 0 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, 0.927
• PP5: Variant 1-156115012-A-G is Pathogenic according to our data. Variant chr1-156115012-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 476837.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr1-156115012-A-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LMNA	NM_170707.4	c.94A>G	p.Lys32Glu	missense_variant	Exon 1 of 12	ENST00000368300.9	NP_733821.1
LMNA	NM_005572.4	c.94A>G	p.Lys32Glu	missense_variant	Exon 1 of 10	ENST00000677389.1	NP_005563.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
LMNA	ENST00000368300.9	c.94A>G	p.Lys32Glu	missense_variant	Exon 1 of 12	1	NM_170707.4	ENSP00000357283.4
LMNA	ENST00000677389.1	c.94A>G	p.Lys32Glu	missense_variant	Exon 1 of 10		NM_005572.4	ENSP00000503633.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Charcot-Marie-Tooth disease type 2 Pathogenic:1

Sep 15, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces lysine, which is basic and polar, with glutamic acid, which is acidic and polar, at codon 32 of the LMNA protein (p.Lys32Glu). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with autosomal dominant LMNA-related neuromuscular conditions (PMID: 28688748, 32571898; Clinvar). In at least one individual the variant was observed to be de novo. ClinVar contains an entry for this variant (Variation ID: 476837). 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. For these reasons, this variant has been classified as Pathogenic. -

Congenital muscular dystrophy due to LMNA mutation Pathogenic:1

Jun 15, 2018

Broad Center for Mendelian Genomics, Broad Institute of MIT and Harvard

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

The heterozygous p.Lys32Glu variant was identified by our study in one individual with congenital muscular dystrophy. Trio exome analysis showed this variant to be de novo. This variant has been identified in the literature in one affected heterozygous proband (Monges et al. 2011). This variant was absent from large population studies. The Lysine (Lys) at position 32 is highly conserved in mammals and evolutionarily distant species, supporting that a change at this position may not be tolerated. Additionally, computational prediction tools suggest that this variant may impact the protein. A lab has reported this variant as likely pathogenic in Clinvar; however, the phenotype listed is Charcot-Marie-Tooth disease. In summary, although additional studies are required to fully establish its pathogenicity, this variant is likely pathogenic for congenital muscular dystrophy. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
CardioboostCm	Pathogenic	0.99
BayesDel_addAF	Pathogenic	0.46	D
BayesDel_noAF	Pathogenic	0.42
CADD	Pathogenic	30
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.96	.;.;.;D;.
Eigen	Pathogenic	0.90
Eigen_PC	Pathogenic	0.81
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D;D;D;D
M_CAP	Pathogenic	0.92	D
MetaRNN	Pathogenic	0.93	D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	4.1	H;.;H;H;H
PrimateAI	Pathogenic	0.87	D
PROVEAN	Uncertain	-3.5	D;D;D;D;D
REVEL	Pathogenic	0.93
Sift	Uncertain	0.0010	D;D;D;D;D
Sift4G	Uncertain	0.0030	D;D;T;D;D
Polyphen		1.0	D;.;D;D;.
Vest4		0.86
MutPred		0.63		Loss of ubiquitination at K32 (P = 0.0067);Loss of ubiquitination at K32 (P = 0.0067);Loss of ubiquitination at K32 (P = 0.0067);Loss of ubiquitination at K32 (P = 0.0067);Loss of ubiquitination at K32 (P = 0.0067);
MVP		0.96
MPC		2.4
ClinPred		1.0	D
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		3.1
Varity_R		0.93
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: rs1553261891; hg19: chr1-156084803;