NM_000268.4:c.1346_1347delAA

Variant names:

• chr22-29674839-CAA-C
• rs1556001351
• NM_000268.4:c.1346_1347delAA

Variant summary

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

The NM_000268.4(NF2):​c.1346_1347delAA​(p.Lys449ArgfsTer45) variant causes a frameshift 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 Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 32)
• Consequence: NF2 NM_000268.4 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:3
• Conservation: PhyloP100: 9.32

Genes affected

NF2 (HGNC:7773): (NF2, moesin-ezrin-radixin like (MERLIN) tumor suppressor) This gene encodes a protein that is similar to some members of the ERM (ezrin, radixin, moesin) family of proteins that link cytoskeletal components with proteins in the cell membrane. The encoded protein is involved in regulation of contact-dependent inhibition of cell proliferation and functions in cell-cell adhesion and transmembrane signaling. The encoded protein has been shown to interact with cell-surface proteins, proteins involved in cytoskeletal dynamics, and proteins involved in regulating ion transport. Disruption of this protein's function has been implicated in tumorigenesis and metastasis. Mutations in this gene are associated with neurofibromatosis type II which is characterized by nervous system and skin tumors and ocular abnormalities. [provided by RefSeq, May 2022]

ACMG classification

Verdict is Pathogenic. Variant got 18 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 22-29674839-CAA-C is Pathogenic according to our data. Variant chr22-29674839-CAA-C is described in ClinVar as [Pathogenic]. Clinvar id is 453214.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NF2	NM_000268.4	c.1346_1347delAA	p.Lys449ArgfsTer45	frameshift_variant	Exon 13 of 16	ENST00000338641.10	NP_000259.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NF2	ENST00000338641.10	c.1346_1347delAA	p.Lys449ArgfsTer45	frameshift_variant	Exon 13 of 16	1	NM_000268.4	ENSP00000344666.5

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: Pathogenic

Submissions summary: Pathogenic:3

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neurofibromatosis, type 2 Pathogenic:2

Feb 11, 2024

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Lys449Argfs*45) in the NF2 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in NF2 are known to be pathogenic (PMID: 9643284, 16983642). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with NF2-related conditions. ClinVar contains an entry for this variant (Variation ID: 453214). For these reasons, this variant has been classified as Pathogenic. -

Nov 07, 2021

Genome-Nilou Lab

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

not provided Pathogenic:1

Nov 10, 2017

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1346_1347delAA variant has not been published as a pathogenic variant, nor has it been reported as a benign variant to our knowledge. The variant causes a frameshift starting with codon Lysine 449, changes this amino acid to an Arginine residue and creates a premature Stop codon at position 45 of the new reading frame, denoted p.Lys449ArgfsX45. This variant is predicted to cause loss of normal protein function either through protein truncation or nonsense-mediated mRNA decay. The variant is not observed in large population cohorts (Lek et al., 2016). In summary, we consider this variant to be 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: rs1556001351; hg19: chr22-30070828;