rs1553261932

Positions:

• chr1-156115100-T-C

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PM2 PP2 PP3_Moderate

The NM_170707.4(LMNA):​c.182T>C​(p.Leu61Pro) 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. L61F) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: LMNA NM_170707.4 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.01

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 Likely_pathogenic. Variant got 7 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, 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, 0.915

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LMNA	NM_170707.4	c.182T>C	p.Leu61Pro	missense_variant	1/12	ENST00000368300.9
LMNA	NM_005572.4	c.182T>C	p.Leu61Pro	missense_variant	1/10	ENST00000677389.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LMNA	ENST00000368300.9	c.182T>C	p.Leu61Pro	missense_variant	1/12	1	NM_170707.4	P1
LMNA	ENST00000677389.1	c.182T>C	p.Leu61Pro	missense_variant	1/10		NM_005572.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Charcot-Marie-Tooth disease type 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 24, 2017

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 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 disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces leucine with proline at codon 61 of the LMNA protein (p.Leu61Pro). The leucine residue is highly conserved and there is a moderate physicochemical difference between leucine and proline. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
CardioboostCm	Uncertain	0.63
BayesDel_addAF	Pathogenic	0.32	D
BayesDel_noAF	Pathogenic	0.22
CADD	Pathogenic	33
DANN	Uncertain	0.99
Eigen	Uncertain	0.52
Eigen_PC	Uncertain	0.51
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Benign	0.81	T;T;T;T;T
M_CAP	Pathogenic	0.77	D
MetaRNN	Pathogenic	0.91	D;D;D;D;D
MetaSVM	Uncertain	0.65	D
MutationAssessor	Pathogenic	3.4	M;.;M;M;M
MutationTaster	Benign	1.0	D;D;D;D;D
PrimateAI	Uncertain	0.77	T
PROVEAN	Uncertain	-4.0	D;D;D;D;D
REVEL	Pathogenic	0.85
Sift	Uncertain	0.0040	D;D;D;D;D
Sift4G	Benign	0.061	T;D;T;D;T
Polyphen		0.98	D;.;B;D;.
Vest4		0.85
MutPred		0.61		Loss of stability (P = 0.0251);Loss of stability (P = 0.0251);Loss of stability (P = 0.0251);Loss of stability (P = 0.0251);Loss of stability (P = 0.0251);
MVP		0.95
MPC		2.0
ClinPred		0.99	D
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.96
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: rs1553261932; hg19: chr1-156084891;