dbSNP rs1428885377: NF1:c.3114-2A>G (chr17-31230840-A-G) – ACMG Classification: Pathogenic (12 pts)

Variant summary

Our verdict is Pathogenic. Variant got 12 ACMG points: 12P and 0B. PVS1_ModeratePM2PP5_Very_Strong

The NM_001042492.3(NF1):c.3114-2A>G variant causes a splice acceptor, intron change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000697 in 1,435,698 control chromosomes in the GnomAD database, with no homozygous occurrence. 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 Likely pathogenic (★★).

Frequency

Genomes: not found (cov: 32)

Exomes 𝑓: 7.0e-7 ( 0 hom. )

Consequence

NF1
NM_001042492.3 splice_acceptor, intron

Scores

Splicing: ADA: 1.000

Clinical Significance

Pathogenic/Likely pathogenic criteria provided, multiple submitters, no conflicts P:8

Conservation

PhyloP100: 8.91

Variant links:

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 links:

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Pathogenic. Variant got 12 ACMG points.

PVS1

Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.009859155 fraction of the gene. No cryptic splice site detected. Exon removal is inframe change.

PM2

Very rare variant in population databases, with high coverage;

PP5

Variant 17-31230840-A-G is Pathogenic according to our data. Variant chr17-31230840-A-G is described in ClinVar as [Likely_pathogenic]. Clinvar id is 457623.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-31230840-A-G is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NF1	NM_001042492.3 link	c.3114-2A>G		splice_acceptor_variant, intron_variant	Intron 23 of 57	ENST00000358273.9	NP_001035957.1	P21359-1
NF1	NM_000267.3 link	c.3114-2A>G		splice_acceptor_variant, intron_variant	Intron 23 of 56		NP_000258.1	P21359-2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9 link	c.3114-2A>G		splice_acceptor_variant, intron_variant	Intron 23 of 57	1	NM_001042492.3	ENSP00000351015.4		P21359-1

Frequencies

GnomAD3 genomes

Cov.:

GnomAD4 exome

AF:

6.97e-7

AC:

AN:

1435698

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

715848

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.0000254

Gnomad4 SAS exome

AF:

0.00

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.00

GnomAD4 genome

Cov.:

ClinVar

Significance: Pathogenic/Likely pathogenic

Submissions summary: Pathogenic:8

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Neurofibromatosis, type 1

Pathogenic:4

Aug 01, 2022

Human Genetics Bochum, Ruhr University Bochum

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

ACMG criteria used to clasify this variant: PVS1, PM2, PP4 -

Mar 15, 2022

Genome-Nilou Lab

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Nov 11, 2024

NHS Central & South Genomic Laboratory Hub

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

Jan 15, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change affects an acceptor splice site in intron 23 of the NF1 gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in NF1 are known to be pathogenic (PMID: 10712197, 23913538). This variant is not present in population databases (gnomAD no frequency). Disruption of this splice site has been observed in individual(s) with clinical features of neurofibromatosis, type 1 (PMID: 24789688, 39001468; internal data). ClinVar contains an entry for this variant (Variation ID: 457623). Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may disrupt the consensus splice site. For these reasons, this variant has been classified as Pathogenic. -

not provided

Pathogenic:1

Dec 11, 2024

GeneDx

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Canonical splice site variant expected to result in aberrant splicing, although in the absence of functional evidence the actual effect of this sequence change is unknown.; Deletions involving coding exons of this gene are a known mechanism of disease (HGMD); Not observed at significant frequency in large population cohorts (gnomAD); This variant is associated with the following publications: (PMID: 24789688, 10712197, 16199547, 23913538, Ognibene2023, 2121369, 25486365) -

Café-au-lait macules with pulmonary stenosis

Pathogenic:1

Dec 12, 2023

3billion

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The variant is not observed in the gnomAD v2.1.1 dataset. Predicted Consequence/Location: Canonical splice site: predicted to alter splicing and result in a loss or disruption of normal protein function. Multiple pathogenic loss-of-function variants are reported downstream of the variant. The variant has been reported at least twice as pathogenic with clinical assertions and evidence for the classification (ClinVar ID: VCV000457623 /PMID: 24789688). Therefore, this variant is classified as Pathogenic according to the recommendation of ACMG/AMP guideline. -

Hereditary cancer-predisposing syndrome;CN230736:Cardiovascular phenotype

Pathogenic:1

Feb 20, 2024

Ambry Genetics

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.3114-2A>G intronic variant results from an A to G substitution two nucleotides upstream from coding exon 24 in the NF1 gene. This variant has been reported in individual(s) with a clinical or suspected diagnosis of neurofibromatosis type 1 (Xu W et al. Int J Mol Med, 2014 Jul;34:53-60). RNA studies have demonstrated that this alteration results in skipping of exon 24 (Xu W et al. Int J Mol Med, 2014 Jul;34:53-60; Ambry internal data). This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice acceptor site and will result in the creation or strengthening of a novel splice acceptor site. This variant is considered to be rare based on population cohorts in the Genome Aggregation Database (gnomAD). Based on the majority of available evidence to date, this variant is likely to be pathogenic. -

RASopathy

Pathogenic:1

Jul 01, 2023

Division of Human Genetics, National Health Laboratory Service/University of the Witwatersrand

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: research

- -

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

BayesDel_addAF

Pathogenic

0.33

BayesDel_noAF

Pathogenic

0.24

CADD

Pathogenic

DANN

Uncertain

0.99

Eigen

Pathogenic

1.1

Eigen_PC

Pathogenic

0.91

FATHMM_MKL

Pathogenic

0.99

GERP RS

4.9

Splicing

Name

Calibrated prediction

Score

Prediction

dbscSNV1_ADA

Pathogenic

1.0

dbscSNV1_RF

Pathogenic

0.93

SpliceAI score (max)

1.0

Details are displayed if max score is > 0.2

DS_AG_spliceai

0.82

Position offset: 9

DS_AL_spliceai

1.0

Position offset: 2

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

Publications

LitVar

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

LitVar

Other links and lift over