chr22-29639215-A-T

Position:

• chr22-29639215-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_000268.4(NF2):​c.363+3A>T variant causes a splice region, 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. 2/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 31)
• Consequence: NF2 NM_000268.4 splice_region, intron
• Scores: Splicing: ADA: 0.9994
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 3.48

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]

NF2 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NF2	NM_000268.4	c.363+3A>T		splice_region_variant, intron_variant		ENST00000338641.10	NP_000259.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NF2	ENST00000338641.10	c.363+3A>T		splice_region_variant, intron_variant		1	NM_000268.4	ENSP00000344666.5

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Pathogenic:1

Likely pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 01, 2024

The c.363+3A>T intronic variant results from an A to T substitution 3 nucleotides after coding exon 3 in the NF2 gene. This nucleotide position is well conserved in available vertebrate species. This variant has been observed in at least one individual with a personal and/or family history that is consistent with NF2-related schwannomatosis (Ambry internal data). In silico splice site analysis predicts that this alteration may weaken the native splice donor site. RNA studies have demonstrated that this alteration results in abnormal splicing in the set of samples tested (Ambry internal data). Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

Neurofibromatosis, type 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Jul 02, 2016

In summary, this is a novel intronic change with uncertain impact on splicing. It has been classified as a Variant of Uncertain Significance. Nucleotide substitutions within the consensus splice site are relatively common causes of aberrant splicing (PMID: 17576681, 9536098). Algorithms developed to predict the effect of nucleotide changes on mRNA splicing suggest that this variant may alter mRNA splicing, but this prediction has not been confirmed by published transcriptional studies. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a NF2-related disease. This sequence change falls in intron 3 of the NF2 mRNA. It does not directly change the encoded amino acid sequence of the NF2 protein, but it affects a nucleotide within the consensus splice site of the intron. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.33
CADD	Benign	20
DANN	Benign	0.93
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.89
SpliceAI score (max)		0.40		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.40		Position offset: -3

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

Publications

LitVar

Other links and lift over

dbSNP: rs1060503669; hg19: chr22-30035204;