rs267607552

Positions:

• chr1-156136437-G-A
• chr1-156136437-G-T

Variant summary

Our verdict is Pathogenic. Variant got 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_170707.4(LMNA):​c.1380+1G>A variant causes a splice donor, intron 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. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: LMNA NM_170707.4 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3 O:2
• Conservation: PhyloP100: 9.92

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]

LMNA (HGNC:):

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, LoF is a know mechanism of disease, No cryptic splice site detected. Exon removal results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 1-156136437-G-A is Pathogenic according to our data. Variant chr1-156136437-G-A is described in ClinVar as [Pathogenic]. Clinvar id is 66817.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr1-156136437-G-A is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LMNA	NM_170707.4	c.1380+1G>A		splice_donor_variant, intron_variant		ENST00000368300.9	NP_733821.1
LMNA	NM_005572.4	c.1380+1G>A		splice_donor_variant, intron_variant		ENST00000677389.1	NP_005563.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LMNA	ENST00000368300.9	c.1380+1G>A		splice_donor_variant, intron_variant		1	NM_170707.4	ENSP00000357283.4
LMNA	ENST00000677389.1	c.1380+1G>A		splice_donor_variant, intron_variant			NM_005572.4	ENSP00000503633.1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:3 Other:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not provided Pathogenic:1 Other:1

not provided, no classification provided	literature only	Epithelial Biology; Institute of Medical Biology, Singapore	-	- -
Pathogenic, criteria provided, single submitter	clinical testing	GeneDx	Feb 21, 2024	Canonical splice site variant predicted to result in a null allele in a gene for which loss of function is a known mechanism of disease; Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 26688388, 18035086, 23349452, 22326558, 25525159, 27813223, 28436997, 31383942, 21846512) -

Charcot-Marie-Tooth disease type 2 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Apr 15, 2023

For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. ClinVar contains an entry for this variant (Variation ID: 66817). This variant is also known as IVS7+1G>A. Disruption of this splice site has been observed in individuals with laminopathies (PMID: 18035086, 22326558). This variant is not present in population databases (gnomAD no frequency). This sequence change affects a donor splice site in intron 7 of the LMNA gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in LMNA are known to be pathogenic (PMID: 18585512, 18926329). -

Cardiovascular phenotype Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 27, 2022

The c.1380+1G>A intronic pathogenic mutation results from a G to A substitution one nucleotide after coding exon 7 of the LMNA gene. This variant has been detected in multiple individual with dilated cardiomyopathy (DCM) and/or cardiac conduction defects, and co-segregation with disease has been reported in some families (van Tintelen JP et al. Am Heart J, 2007 Dec;154:1130-9; Millat G et al. Eur J Med Genet, 2011 Aug;54:e570-5; Jansweijer JA et al. Eur J Heart Fail, 2017 04;19:512-521; Park J et al. Genet Med, 2020 01;22:102-111). This variant has also been reported in an individual with DCM and limb-girdle muscular dystrophy (LGMD) (Magagnotti C et al. Biochim Biophys Acta, 2012 Jun;1822:970-9). This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). In silico splice site analysis predicts that this alteration will weaken the native splice donor site. Alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. Based on the supporting evidence, this alteration is interpreted as a disease-causing mutation. -

Hutchinson-Gilford syndrome;C0410190:Emery-Dreifuss muscular dystrophy 2, autosomal dominant;C1449563:Dilated cardiomyopathy 1A;C1720860:Familial partial lipodystrophy, Dunnigan type;C1854154:Charcot-Marie-Tooth disease type 2B1;C2750035:Emery-Dreifuss muscular dystrophy 3, autosomal recessive;C2750785:Congenital muscular dystrophy due to LMNA mutation;C5399785:Mandibuloacral dysplasia with type A lipodystrophy Other:1

not provided, no classification provided

phenotyping only

GenomeConnect - Invitae Patient Insights Network

-

Variant interpreted as Pathogenic and reported on 09-29-2020 by Invitae. GenomeConnect-Invitae Patient Insights Network assertions are reported exactly as they appear on the patient-provided report from the testing laboratory. Registry team members make no attempt to reinterpret the clinical significance of the variant. Phenotypic details are available under supporting information. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.60	D
BayesDel_noAF	Pathogenic	0.36
CADD	Pathogenic	33
DANN	Uncertain	1.0
Eigen	Pathogenic	1.3
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	0.98	D
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DL_spliceai		1.0		Position offset: -1

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

Publications

LitVar

Other links and lift over

dbSNP: rs267607552; hg19: chr1-156106228;