X-120442599-C-A

Position:

• chrX-120442599-C-A

Variant summary

Our verdict is Pathogenic. Variant got 10 ACMG points: 10P and 0B. PM2 PM5 PP3_Strong PP5_Moderate

The NM_002294.3(LAMP2):​c.928G>T​(p.Val310Phe) variant causes a missense, splice region change. 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. V310I) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 22)
• Consequence: LAMP2 NM_002294.3 missense, splice_region
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 4.51

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 Pathogenic. Variant got 10 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chrX-120442599-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 9982.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant X-120442599-C-A is Pathogenic according to our data. Variant chrX-120442599-C-A is described in ClinVar as [Pathogenic]. Clinvar id is 835011.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.928G>T	p.Val310Phe	missense_variant, splice_region_variant	7/9	ENST00000200639.9
LAMP2	NM_001122606.1	c.928G>T	p.Val310Phe	missense_variant, splice_region_variant	7/9
LAMP2	NM_013995.2	c.928G>T	p.Val310Phe	missense_variant, splice_region_variant	7/9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
LAMP2	ENST00000200639.9	c.928G>T	p.Val310Phe	missense_variant, splice_region_variant	7/9	1	NM_002294.3	P3

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 28

GnomAD4 genome Cov.: 22

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Danon disease Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 03, 2023

For these reasons, this variant has been classified as Pathogenic. This variant disrupts the c.928G nucleotide in the LAMP2 gene. Other variant(s) that disrupt this nucleotide have been determined to be pathogenic (PMID: 15673802, 16217705, 19373884, 29753918). This suggests that this nucleotide is clinically significant, and that variants that disrupt this position are likely to be disease-causing. Variants that disrupt the consensus splice site are a relatively common cause of aberrant splicing (PMID: 17576681, 9536098). Studies have shown that this missense change results in skipping of exon 7 and introduces a premature termination codon (PMID: 33226119). The resulting mRNA is expected to undergo nonsense-mediated decay. An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. ClinVar contains an entry for this variant (Variation ID: 835011). This missense change has been observed in individual(s) with Danon disease (PMID: 33226119). In at least one individual the variant was observed to be de novo. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces valine, which is neutral and non-polar, with phenylalanine, which is neutral and non-polar, at codon 310 of the LAMP2 protein (p.Val310Phe). RNA analysis indicates that this missense change induces altered splicing and may result in an absent or disrupted protein product. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
CardioboostCm	Uncertain	0.17
BayesDel_addAF	Benign	-0.13	T
BayesDel_noAF	Benign	-0.43
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Benign	0.33	.;T;.
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.90	D;D;D
M_CAP	Pathogenic	0.40	D
MetaRNN	Pathogenic	0.77	D;D;D
MetaSVM	Benign	-0.60	T
MutationAssessor	Uncertain	2.6	M;M;M
MutationTaster	Benign	0.95	D;D;N;N;N
PrimateAI	Benign	0.46	T
PROVEAN	Uncertain	-2.5	N;N;N
REVEL	Uncertain	0.30
Sift	Benign	0.043	D;D;D
Sift4G	Benign	0.13	T;T;T
Polyphen		0.027, 0.98	.;B;D
Vest4		0.44
MutPred		0.74		Gain of sheet (P = 0.0827);Gain of sheet (P = 0.0827);Gain of sheet (P = 0.0827);
MVP		0.62
MPC		0.45
ClinPred		0.92	D
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.68
gMVP		0.43

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	1.0
SpliceAI score (max)		0.88		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.88		Position offset: 0

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

Publications

LitVar

Other links and lift over

dbSNP: rs104894858; hg19: chrX-119576454;