17-31232068-T-C

Position:

• chr17-31232068-T-C

Variant summary

Our verdict is Benign. Variant got -10 ACMG points: 2P and 12B. PM2 BP4_Strong BP6_Very_Strong

The NM_001042492.3(NF1):​c.3198-5T>C variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000238 in 1,258,086 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: not found (cov: 29)
  • Exomes 𝑓: 0.0000024 (0 hom.)
• Consequence: NF1 NM_001042492.3 splice_region, intron
• Scores: Splicing: ADA: 0.00005474
• Clinical Significance: Likely benign criteria provided, multiple submitters, no conflicts B:6
• Conservation: PhyloP100: -0.305

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 (HGNC:):

ACMG classification

Verdict is Benign. Variant got -10 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.86).
• BP6: Variant 17-31232068-T-C is Benign according to our data. Variant chr17-31232068-T-C is described in ClinVar as [Likely_benign]. Clinvar id is 142679.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NF1	NM_001042492.3	c.3198-5T>C		splice_region_variant, intron_variant		ENST00000358273.9	NP_001035957.1
NF1	NM_000267.3	c.3198-5T>C		splice_region_variant, intron_variant			NP_000258.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.3198-5T>C		splice_region_variant, intron_variant		1	NM_001042492.3	ENSP00000351015.4

Frequencies

GnomAD3 genomes Cov.: 29

GnomAD3 exomes AF: 0.0000129 AC: 2 AN: 155524 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 83358

Gnomad AFR exome AF: 0.000105

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.0000151

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000238 AC: 3 AN: 1258086 Hom.: 0 Cov.: 20 AF XY: 0.00000319 AC XY: 2 AN XY: 626018

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000311

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 29

ClinVar

Significance: Likely benign

Submissions summary: Benign:6

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Feb 08, 2024	Variant summary: NF1 c.3198-5T>C alters a non-conserved nucleotide located close to a canonical splice site and therefore could affect mRNA splicing, leading to a significantly altered protein sequence. Consensus agreement among computation tools predict no significant impact on normal splicing. However, these predictions have yet to be confirmed by functional studies. The variant allele was found at a frequency of 1.3e-05 in 155524 control chromosomes (gnomAD). The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. To our knowledge, no occurrence of c.3198-5T>C in individuals affected with Neurofibromatosis Type 1 and no experimental evidence demonstrating its impact on protein function have been reported. ClinVar contains an entry for this variant (Variation ID: 142679). Based on the evidence outlined above, the variant was classified as likely benign. -
Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Jan 08, 2018	This variant is considered likely benign or benign based on one or more of the following criteria: it is a conservative change, it occurs at a poorly conserved position in the protein, it is predicted to be benign by multiple in silico algorithms, and/or has population frequency not consistent with disease. -

Neurofibromatosis, type 1 Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Aug 28, 2023	- -
Likely benign, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Mar 15, 2022	- -

Hereditary cancer-predisposing syndrome;CN230736:Cardiovascular phenotype Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 27, 2020

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Hereditary cancer-predisposing syndrome Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 04, 2014

In silico models in agreement (benign);Other data supporting benign classification;Other strong data supporting benign classification -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.86
CADD	Benign	1.5
DANN	Benign	0.69

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.000055
dbscSNV1_RF	Benign	0.0060
SpliceAI score (max)		0.10		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: rs587782639; hg19: chr17-29559086;