1-156135892-C-A

Position:

• chr1-156135892-C-A

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_170707.4(LMNA):​c.937-9C>A variant causes a splice polypyrimidine tract, intron change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: LMNA NM_170707.4 splice_polypyrimidine_tract, intron
• Scores: Splicing: ADA: 0.007300
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 0.0510

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_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.79).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LMNA	NM_005572.4	c.937-9C>A		splice_polypyrimidine_tract_variant, intron_variant		ENST00000677389.1
LMNA	NM_170707.4	c.937-9C>A		splice_polypyrimidine_tract_variant, intron_variant		ENST00000368300.9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LMNA	ENST00000368300.9	c.937-9C>A		splice_polypyrimidine_tract_variant, intron_variant		1	NM_170707.4	P1
LMNA	ENST00000677389.1	c.937-9C>A		splice_polypyrimidine_tract_variant, intron_variant			NM_005572.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Charcot-Marie-Tooth disease type 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jun 02, 2023

Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. ClinVar contains an entry for this variant (Variation ID: 861693). This variant has not been reported in the literature in individuals affected with LMNA-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change falls in intron 5 of the LMNA gene. It does not directly change the encoded amino acid sequence of the LMNA protein. 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

Nov 20, 2023

This variant causes a C to A nucleotide substitution at the -9 position of intron 5 of the LMNA gene. To our knowledge, functional studies have not been reported for this variant. This variant has not been reported in individuals affected with LMNA-related disorders in the literature. This variant has not been identified 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.79
CADD	Benign	1.2
DANN	Benign	0.46
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.0

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.0073
dbscSNV1_RF	Benign	0.072
SpliceAI score (max)		0.39		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.39		Position offset: -31

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

Publications

LitVar

Other links and lift over

dbSNP: rs1332011298; hg19: chr1-156105683;