rs1418965797

Variant names:

• chr17-31259031-G-A
• rs1418965797
• NM_001042492.3:c.4333-1G>A

Your query was ambiguous. Multiple possible variants found:

• chr17-31259031-G-A
• chr17-31259031-G-C
• chr17-31259031-G-T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PVS1_Moderate PM2 PP5_Moderate

The NM_001042492.3(NF1):​c.4333-1G>A variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. 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 (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000021 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: NF1 NM_001042492.3 splice_acceptor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 9.30
• Publications: 1 publications found

Genes affected

NF1 (HGNC:7765): (neurofibromin 1) This gene product appears to function as a negative regulator of the ras signal transduction pathway. Mutations in this gene have been linked to neurofibromatosis type 1, juvenile myelomonocytic leukemia and Watson syndrome. The mRNA for this gene is subject to RNA editing (CGA>UGA->Arg1306Term) resulting in premature translation termination. Alternatively spliced transcript variants encoding different isoforms have also been described for this gene. [provided by RefSeq, Jul 2008]

NF1 Gene-Disease associations (from GenCC):

• neurofibromatosis type 1

  Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, PanelApp Australia, G2P, Genomics England PanelApp
• neurofibromatosis-Noonan syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp, PanelApp Australia
• Moyamoya disease

  Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
• hereditary pheochromocytoma-paraganglioma

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• familial ovarian cancer

  Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.011502347 fraction of the gene. Cryptic splice site detected, with MaxEntScore 4.8, offset of 9, new splice context is: ttattgtgtaaatacttcAGagt. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-31259031-G-A is Pathogenic according to our data. Variant chr17-31259031-G-A is described in ClinVar as Pathogenic. ClinVar VariationId is 457692.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NF1	NM_001042492.3	c.4333-1G>A		splice_acceptor_variant, intron_variant	Intron 32 of 57	ENST00000358273.9	NP_001035957.1
NF1	NM_000267.4	c.4270-1G>A		splice_acceptor_variant, intron_variant	Intron 31 of 56		NP_000258.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.4333-1G>A		splice_acceptor_variant, intron_variant	Intron 32 of 57	1	NM_001042492.3	ENSP00000351015.4

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000440 AC: 1 AN: 227062 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome Data not reliable, filtered out with message: AS_VQSR AF: 0.00000211 AC: 3 AN: 1424358 Hom.: 0 Cov.: 27 AF XY: 0.00000141 AC XY: 1 AN XY: 708710

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 32878

American (AMR) AF: 0.00 AC: 0 AN: 43504

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25362

East Asian (EAS) AF: 0.00 AC: 0 AN: 39246

South Asian (SAS) AF: 0.0000239 AC: 2 AN: 83686

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52094

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5094

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1083712

Other (OTH) AF: 0.0000170 AC: 1 AN: 58782

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Neurofibromatosis, type 1 Pathogenic:1

Nov 15, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Disruption of this splice site has been observed in individuals with clinical features of neurofibromatosis type 1 (PMID: 18800150, 23913538). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change affects an acceptor splice site in intron 31 of the NF1 gene. RNA analysis indicates that disruption of this splice site induces altered splicing and likely results in the loss of 3 amino acid residue(s), but is expected to preserve the integrity of the reading-frame. ClinVar contains an entry for this variant (Variation ID: 457692). For these reasons, this variant has been classified as Pathogenic. This variant disrupts a region of the NF1 protein in which other variant(s) (p.Leu1425Pro) have been determined to be pathogenic (PMID: 10607834, 10712197, 31730495). This suggests that this is a clinically significant region of the protein, and that variants that disrupt it are likely to be disease-causing. Studies have shown that disruption of this splice site results in the activation of a cryptic splice site in exon 32 (PMID: 23913538). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.34
CADD	Pathogenic	36
DANN	Uncertain	0.99
Eigen	Pathogenic	1.1
Eigen_PC	Pathogenic	0.98
FATHMM_MKL	Pathogenic	0.97	D
PhyloP100		9.3
GERP RS		5.8
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		0.99		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.96		Position offset: 10
DS_AL_spliceai		0.99		Position offset: 1

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

Other links and lift over

dbSNP: rs1418965797; hg19: chr17-29586049; COSMIC: COSV62214630; COSMIC: COSV62214630;