chr1-156135230-TGGG-T

Position:

• chr1-156135230-TGGG-T

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM2 PM4_Supporting PP5_Moderate

The NM_170707.4(LMNA):​c.857_859del​(p.Gly286del) variant causes a inframe deletion change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: LMNA NM_170707.4 inframe_deletion
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 8.15

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.

• 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.
• PP5: Variant 1-156135230-TGGG-T is Pathogenic according to our data. Variant chr1-156135230-TGGG-T is described in ClinVar as [Likely_pathogenic]. Clinvar id is 648794.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
LMNA	NM_005572.4	c.857_859del	p.Gly286del	inframe_deletion	5/10	ENST00000677389.1	NP_005563.1
LMNA	NM_170707.4	c.857_859del	p.Gly286del	inframe_deletion	5/12	ENST00000368300.9	NP_733821.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
LMNA	ENST00000368300.9	c.857_859del	p.Gly286del	inframe_deletion	5/12	1	NM_170707.4	ENSP00000357283	P1
LMNA	ENST00000677389.1	c.857_859del	p.Gly286del	inframe_deletion	5/10		NM_005572.4	ENSP00000503633

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Charcot-Marie-Tooth disease type 2 Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Sep 04, 2018

This variant, c.857_859delGGG, results in the deletion of 1 amino acid(s) of the LMNA protein (p.Gly286del), but otherwise preserves the integrity of the reading frame. This variant is not present in population databases (ExAC no frequency). This variant has been observed to be de novo in an individual affected with cardiomyopathy (Invitae). Experimental studies and prediction algorithms are not available for this variant, and the functional significance of the affected amino acid(s) is currently unknown. In summary, the currently available evidence indicates that the variant is pathogenic, but additional data are needed to prove that conclusively. Therefore, this variant has been classified as Likely Pathogenic. -

Computational scores

Source: dbNSFP v4.3

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: rs59564495; hg19: chr1-156105021;