rs727504557

chrX-120441823-CT-C

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PVS1_Strong PM2 PP5_Moderate

The NM_002294.3(LAMP2):c.999del(p.Glu334SerfsTer12) variant causes a frameshift change involving the alteration of a non-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: 22)
• Consequence: LAMP2 NM_002294.3 frameshift
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 1.29

Genes affected

LAMP2 (HGNC:6501): (lysosomal associated membrane protein 2) The protein encoded by this gene is a member of a family of membrane glycoproteins. This glycoprotein provides selectins with carbohydrate ligands. It may play a role in tumor cell metastasis. It may also function in the protection, maintenance, and adhesion of the lysosome. Alternative splicing of this gene results in multiple transcript variants encoding distinct proteins. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant is located in the 3'-most 50 bp of the penultimate exon, not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.19 CDS is truncated, and there are 3 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant X-120441823-CT-C is Pathogenic according to our data. Variant chrX-120441823-CT-C is described in ClinVar as [Likely_pathogenic]. Clinvar id is 178945.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
LAMP2	NM_002294.3	c.999del	p.Glu334SerfsTer12	frameshift_variant	8/9	ENST00000200639.9
LAMP2	NM_001122606.1	c.999del	p.Glu334SerfsTer12	frameshift_variant	8/9
LAMP2	NM_013995.2	c.999del	p.Glu334SerfsTer12	frameshift_variant	8/9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LAMP2	ENST00000200639.9	c.999del	p.Glu334SerfsTer12	frameshift_variant	8/9	1	NM_002294.3	P3

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 28

GnomAD4 genome Cov.: 22

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Primary dilated cardiomyopathy Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Feb 27, 2014

The Glu334fs variant in LAMP2 has now been identified by our laboratory in 1 ind ividual with DCM and ARVC and segregated with disease in 2 affected relatives. I t was absent from large population studies. This frameshift variant is predicted to alter the protein's amino acid sequence beginning at position 334 and lead t o premature termination codon 12 amino acids downstream. This alteration is then predicted to lead to a truncated or absent protein. Loss of function of the LA MP2 gene is associated with Danon disease. In summary, this variant is likely to be pathogenic, though additional studies are required to fully establish its cl inical significance. -

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: rs727504557; hg19: chrX-119575678;