rs397517910

Positions:

• chr1-156135236-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP2

The NM_170707.4(LMNA):​c.860C>T​(p.Ala287Val) variant causes a missense change. The variant allele was found at a frequency of 0.00000616 in 1,461,478 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A287T) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000062 (0 hom.)
• Consequence: LMNA NM_170707.4 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 3.96

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 Uncertain_significance. Variant got 5 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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LMNA	NM_170707.4	c.860C>T	p.Ala287Val	missense_variant	5/12	ENST00000368300.9
LMNA	NM_005572.4	c.860C>T	p.Ala287Val	missense_variant	5/10	ENST00000677389.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LMNA	ENST00000368300.9	c.860C>T	p.Ala287Val	missense_variant	5/12	1	NM_170707.4	P1
LMNA	ENST00000677389.1	c.860C>T	p.Ala287Val	missense_variant	5/10		NM_005572.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251034 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135810

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000882

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000616 AC: 9 AN: 1461478 Hom.: 0 Cov.: 34 AF XY: 0.00000550 AC XY: 4 AN XY: 727054

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.0000116

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000719

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Alfa AF: 0.0000282 Hom.: 0

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Feb 13, 2012

The Ala287Val variant (LMNA) has not been reported in the literature nor previou sly identified by our laboratory. Computational analyses (biochemical amino acid properties, conservation, PolyPhen2, SIFT, AlignGVGD) do not provide strong sup port for or against pathogenicity. In the absence of additional information, th e clinical significance of this variant cannot be determined. -

Cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Nov 08, 2019

This missense variant replaces alanine with valine at codon 287 of the LMNA protein. 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). Splice site prediction tools suggest that this variant may not impact RNA splicing. To our knowledge, functional studies have not been performed for this variant. This variant has not been reported in individuals affected with cardiovascular disorders in the literature. This variant has been identified in 1/251034 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. -

Charcot-Marie-Tooth disease type 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Apr 11, 2021

This variant is not present in population databases (ExAC no frequency). 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. 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 tolerated, 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. ClinVar contains an entry for this variant (Variation ID: 48087). This sequence change replaces alanine with valine at codon 287 of the LMNA protein (p.Ala287Val). The alanine residue is highly conserved and there is a small physicochemical difference between alanine and valine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.36
CardioboostCm	Benign	0.0027
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.090
CADD	Pathogenic	26
DANN	Pathogenic	1.0
Eigen	Uncertain	0.24
Eigen_PC	Uncertain	0.36
FATHMM_MKL	Uncertain	0.97	D
LIST_S2	Uncertain	0.92	D;D;D;D;D;D;D;D
M_CAP	Uncertain	0.17	D
MetaRNN	Uncertain	0.61	D;D;D;D;D;D;D;D
MetaSVM	Uncertain	0.25	D
MutationAssessor	Uncertain	2.5	M;.;M;M;M;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.59	T
PROVEAN	Uncertain	-2.6	D;D;D;D;D;D;D;D
REVEL	Uncertain	0.59
Sift	Benign	0.11	T;T;T;T;T;T;T;T
Sift4G	Benign	0.10	T;T;T;T;T;T;T;T
Polyphen		0.32	B;.;B;B;.;.;B;.
Vest4		0.62
MutPred		0.49		Loss of MoRF binding (P = 0.2268);Loss of MoRF binding (P = 0.2268);Loss of MoRF binding (P = 0.2268);Loss of MoRF binding (P = 0.2268);Loss of MoRF binding (P = 0.2268);.;.;.;
MVP		0.86
MPC		1.0
ClinPred		0.90	D
GERP RS		5.6
Varity_R		0.094
gMVP		0.90

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: rs397517910; hg19: chr1-156105027;