chr1-156115152-G-C

Variant names:

• chr1-156115152-G-C
• rs727505038
• NM_170707.4:c.234G>C

Variant summary

Our verdict is Pathogenic. The variant received 10 ACMG points: 10P and 0B. PS1 PM1 PM2 PP3_Moderate

The NM_170707.4(LMNA):​c.234G>C​(p.Lys78Asn) variant causes a missense change involving the alteration of a non-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 Uncertain significance (★★). Another nucleotide change resulting in the same amino acid substitution has been previously reported as Likely pathogenic in ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K78E) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: LMNA NM_170707.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 3.48

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

Our verdict: Pathogenic. The variant received 10 ACMG points.

• PS1: Transcript NM_170707.4 (LMNA) is affected with MISSENSE_VARIANT having same AA change as one Pathogenic present in ClinVar as 444011
• PM1: In a hotspot region, there are 6 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 11 uncertain in NM_170707.4
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.849

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
LMNA	NM_170707.4	c.234G>C	p.Lys78Asn	missense_variant	Exon 1 of 12	ENST00000368300.9	NP_733821.1
LMNA	NM_005572.4	c.234G>C	p.Lys78Asn	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.234G>C	p.Lys78Asn	missense_variant	Exon 1 of 12	1	NM_170707.4	ENSP00000357283.4
LMNA	ENST00000677389.1	c.234G>C	p.Lys78Asn	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: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:1

Apr 04, 2014

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.Lys78Asn variant in LMNA has been identified in 1 individual with DCM and atrial fibrillation (LMM data) and was absent from large population studies. Com putational prediction tools and conservation analysis suggest that the variant m ay impact the protein, though this information is not predictive enough to deter mine pathogenicity. In summary, the clinical significance of this variant is unc ertain. ACMG/AMP Criteria applied: PM2, PP3, PP4. -

Charcot-Marie-Tooth disease type 2 Uncertain:1

Oct 18, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces lysine, which is basic and polar, with asparagine, which is neutral and polar, at codon 78 of the LMNA protein (p.Lys78Asn). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individual(s) with clinical features of LMNA-related conditions (PMID: 27884249, 36548481). ClinVar contains an entry for this variant (Variation ID: 179669). 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. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
CardioboostCm	Uncertain	0.77
BayesDel_addAF	Uncertain	0.15	D
BayesDel_noAF	Uncertain	-0.030
CADD	Pathogenic	31
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.94	.;.;.;D;.
Eigen	Uncertain	0.60
Eigen_PC	Uncertain	0.58
FATHMM_MKL	Uncertain	0.92	D
LIST_S2	Uncertain	0.96	D;D;D;D;D
M_CAP	Pathogenic	0.36	D
MetaRNN	Pathogenic	0.85	D;D;D;D;D
MetaSVM	Uncertain	0.73	D
MutationAssessor	Pathogenic	3.0	M;.;M;M;M
PrimateAI	Pathogenic	0.83	D
PROVEAN	Uncertain	-3.7	D;D;D;D;D
REVEL	Pathogenic	0.67
Sift	Uncertain	0.0010	D;D;D;D;D
Sift4G	Uncertain	0.015	D;D;D;D;D
Polyphen		0.86	P;.;D;P;.
Vest4		0.86
MutPred		0.44		Loss of ubiquitination at K78 (P = 0.0047);Loss of ubiquitination at K78 (P = 0.0047);Loss of ubiquitination at K78 (P = 0.0047);Loss of ubiquitination at K78 (P = 0.0047);Loss of ubiquitination at K78 (P = 0.0047);
MVP		0.90
MPC		2.3
ClinPred		1.0	D
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.8
Varity_R		0.95
gMVP		0.99
Mutation Taster		=1/99	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

Publications

LitVar

Other links and lift over

dbSNP: rs727505038; hg19: chr1-156084943;