17-31232145-A-C

Position:

• chr17-31232145-A-C

Variant summary

Our verdict is Benign. Variant got -17 ACMG points: 0P and 17B. BP4_Strong BP6_Very_Strong BP7 BS2

The NM_001042492.3(NF1):​c.3270A>C​(p.Gly1090Gly) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00013 in 1,596,900 control chromosomes in the GnomAD database, including 2 homozygotes. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★). Synonymous variant affecting the same amino acid position (i.e. G1090G) has been classified as Benign.

• Frequency:
  • Genomes: 𝑓 0.00080 (2 hom., cov: 29)
  • Exomes 𝑓: 0.000064 (0 hom.)
• Consequence: NF1 NM_001042492.3 synonymous
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:13
• Conservation: PhyloP100: 1.44

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 -17 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.52).
• BP6: Variant 17-31232145-A-C is Benign according to our data. Variant chr17-31232145-A-C is described in ClinVar as [Likely_benign]. Clinvar id is 184233.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr17-31232145-A-C is described in Lovd as [Likely_benign].
• BP7: Synonymous conserved (PhyloP=1.44 with no splicing effect.
• BS2: High AC in GnomAd4 at 115 AD gene.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NF1	NM_001042492.3	c.3270A>C	p.Gly1090Gly	synonymous_variant	25/58	ENST00000358273.9	NP_001035957.1
NF1	NM_000267.3	c.3270A>C	p.Gly1090Gly	synonymous_variant	25/57		NP_000258.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.3270A>C	p.Gly1090Gly	synonymous_variant	25/58	1	NM_001042492.3	ENSP00000351015.4

Frequencies

GnomAD3 genomes AF: 0.000789 AC: 114 AN: 144504 Hom.: 2 Cov.: 29

Gnomad AFR AF: 0.00283

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.0000732

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00151

GnomAD3 exomes AF: 0.000155 AC: 39 AN: 251236 Hom.: 0 AF XY: 0.000133 AC XY: 18 AN XY: 135798

Gnomad AFR exome AF: 0.00215

Gnomad AMR exome AF: 0.0000868

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: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000640 AC: 93 AN: 1452316 Hom.: 0 Cov.: 31 AF XY: 0.0000595 AC XY: 43 AN XY: 722624

Gnomad4 AFR exome AF: 0.00244

Gnomad4 AMR exome AF: 0.000135

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: 9.04e-7

Gnomad4 OTH exome AF: 0.0000836

GnomAD4 genome AF: 0.000795 AC: 115 AN: 144584 Hom.: 2 Cov.: 29 AF XY: 0.000773 AC XY: 54 AN XY: 69890

Gnomad4 AFR AF: 0.00285

Gnomad4 AMR AF: 0.0000731

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.00

Gnomad4 OTH AF: 0.00150

Alfa AF: 0.000391 Hom.: 0

Bravo AF: 0.000782

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:13

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:6

Likely benign, criteria provided, single submitter	clinical testing	GeneDx	Dec 28, 2017	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. -
Likely benign, criteria provided, single submitter	clinical testing	PreventionGenetics, part of Exact Sciences	-	- -
Benign, criteria provided, single submitter	clinical testing	Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine	Nov 24, 2014	Gly1090Gly in exon 25 of NF1: This variant is not expected to have clinical sign ificance because it does not alter an amino acid residue and is not located with in the splice consensus sequence. It has been identified in 1.4% (7/492) of Afri can chromosomes from a broad population by the 1000 Genomes Project (http://www. ncbi.nlm.nih.gov/projects/SNP; dbSNP rs150015024). -
Benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Oct 19, 2018	Variant summary: NF1 c.3270A>C alters a non-conserved nucleotide resulting in a synonymous change. 5/5 computational 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 0.00021 in 276484 control chromosomes, predominantly at a frequency of 0.0023 within the African subpopulation in the gnomAD database. The observed variant frequency within African control individuals in the gnomAD database is approximately 11-fold of the estimated maximal expected allele frequency for a pathogenic variant in NF1 causing Neurofibromatosis Type 1 phenotype (0.00021), strongly suggesting that the variant is a benign polymorphism found primarily in populations of African origin. To our knowledge, no occurrence of c.3270A>C in individuals affected with Neurofibromatosis Type 1 and no experimental evidence demonstrating its impact on protein function have been reported. Three clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar after 2014 without evidence for independent evaluation. All laboratories classified the variant as benign/likely benign. Based on the evidence outlined above, the variant was classified as benign. -
Likely benign, criteria provided, single submitter	clinical testing	Genetic Services Laboratory, University of Chicago	Dec 31, 2020	- -
Benign, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	Aug 19, 2022	The frequency of this variant in the general population (http://gnomad.broadinstitute.org) is higher than would generally be expected for pathogenic variants in this gene. Computational tools yielded predictions that this variant is unlikely to have an effect on normal RNA splicing. This nucleotide position exhibits low evolutionary conservation. -

Neurofibromatosis, type 1 Benign:3

Likely benign, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Mar 15, 2022	- -
Benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Feb 01, 2024	- -
Likely benign, criteria provided, single submitter	clinical testing	Genome Diagnostics Laboratory, The Hospital for Sick Children	Oct 26, 2020	- -

Hereditary cancer-predisposing syndrome Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	Nov 04, 2014	This alteration is classified as likely benign based on a combination of the following: 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. -
Benign, criteria provided, single submitter	curation	Sema4, Sema4	Oct 27, 2020	- -

Neurofibromatosis, familial spinal Benign:1

Benign, criteria provided, single submitter

clinical testing

KCCC/NGS Laboratory, Kuwait Cancer Control Center

Jul 07, 2023

- -

not provided Benign:1

Likely benign, criteria provided, single submitter

clinical testing

CeGaT Center for Human Genetics Tuebingen

Sep 01, 2024

NF1: BP4, BS1 -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.52
CADD	Benign	13
DANN	Benign	0.72
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs150015024; hg19: chr17-29559163;