rs267607579

chr1-156136961-G-GAGA

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PM4_Supporting

The NM_170707.4(LMNA):c.1422_1424dup(p.Gly474_Asp475insGlu) variant causes a inframe insertion change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000342 in 1,461,866 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000034 (0 hom.)
• Consequence: LMNA NM_170707.4 inframe_insertion
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:6 O:1
• Conservation: PhyloP100: 0.440

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, 10 uncertain in NM_170707.4
• PM2: Very rare variant in population databases, with high coverage
• PM4: Nonframeshift variant in NON repetitive region in NM_170707.4. Strenght limited to Supporting due to length of the change: 1aa.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LMNA	NM_005572.4	c.1422_1424dup	p.Gly474_Asp475insGlu	inframe_insertion	8/10	ENST00000677389.1
LMNA	NM_170707.4	c.1422_1424dup	p.Gly474_Asp475insGlu	inframe_insertion	8/12	ENST00000368300.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LMNA	ENST00000368300.9	c.1422_1424dup	p.Gly474_Asp475insGlu	inframe_insertion	8/12	1	NM_170707.4	P1
LMNA	ENST00000677389.1	c.1422_1424dup	p.Gly474_Asp475insGlu	inframe_insertion	8/10		NM_005572.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000342 AC: 5 AN: 1461866 Hom.: 0 Cov.: 32 AF XY: 0.00000550 AC XY: 4 AN XY: 727234

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000450

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:6 Other:1

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Uncertain:2 Other:1

not provided, no classification provided	literature only	Epithelial Biology; Institute of Medical Biology, Singapore	-	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Eurofins Ntd Llc (ga)	Mar 06, 2013	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Revvity Omics, Revvity	Dec 01, 2020	- -

Cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Color Diagnostics, LLC DBA Color Health

Nov 07, 2018

Variant of Uncertain Significance due to insufficient evidence: This variant insert glutamate between codons 474 and 475 in the lamin tail domain of the LMNA protein. Computational splicing tools suggest that this variant may not impact RNA splicing. To our knowledge, functional assays have not been performed for this variant. This variant has been reported in an individual affected with dilated cardiomyopathy (PMID: 18585512). This variant is rare in the general population and has been identified in 0/277264 chromosomes by the Genome Aggregation Database (gnomAD). Available evidence is insufficient to determine the pathogenicity of this variant conclusively. -

Charcot-Marie-Tooth disease type 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Apr 25, 2022

This variant, c.1422_1424dup, results in the insertion of 1 amino acid(s) of the LMNA protein (p.Gly474_Asp475insGlu), but otherwise preserves the integrity of the reading frame. This variant is not present in population databases (gnomAD no frequency). This variant has been observed in individuals with dilated cardiomyopathy and in an individual affected with limb-girdle muscular dystrophy (PMID: 18585512; Invitae). This variant is also known as c.1424_1425insAGA. ClinVar contains an entry for this variant (Variation ID: 95287). Experimental studies and prediction algorithms are not available or were not evaluated, and the functional significance of this variant is currently unknown. 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. -

Primary dilated cardiomyopathy Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

All of Us Research Program, National Institutes of Health

May 23, 2023

Variant of Uncertain Significance due to insufficient evidence: This variant insert glutamate between codons 474 and 475 in the lamin tail domain of the LMNA protein. Computational splicing tools suggest that this variant may not impact RNA splicing. To our knowledge, functional assays have not been performed for this variant. This variant has been reported in an individual affected with dilated cardiomyopathy (PMID: 18585512). This variant is rare in the general population and has been identified in 0/277264 chromosomes by the Genome Aggregation Database (gnomAD). Available evidence is insufficient to determine the pathogenicity of this variant conclusively. -

Cardiovascular phenotype Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 17, 2019

The c.1422_1424dupAGA variant (also known as p.G474_D475insE), located in coding exon 8 of the LMNA gene, results from an in-frame duplication of AGA at nucleotide positions 1422 to 1424. This results in the insertion of a glutamic acid between codons 474 and 475. This variant was reported (as c.1424_1425insAGA) in a dilated cardiomyopathy case with limited clinical details provided (Parks SB et al. Am. Heart J., 2008 Jul;156:161-9). Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs267607579; hg19: chr1-156106752;