17-31352353-C-G

Position:

• chr17-31352353-C-G

Variant summary

Our verdict is Benign. Variant got -12 ACMG points: 0P and 12B. BP4_Moderate BP6_Very_Strong BP7 BS2_Supporting

The NM_001042492.3(NF1):​c.7554C>G​(p.Ala2518Ala) variant causes a synonymous change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000446 in 1,614,004 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely benign (★★).

• Frequency:
  • Genomes: 𝑓 0.00023 (0 hom., cov: 32)
  • Exomes 𝑓: 0.000025 (0 hom.)
• Consequence: NF1 NM_001042492.3 synonymous
• Clinical Significance: Benign/Likely benign criteria provided, multiple submitters, no conflicts B:8
• Conservation: PhyloP100: 0.548

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 -12 ACMG points.

• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.42).
• BP6: Variant 17-31352353-C-G is Benign according to our data. Variant chr17-31352353-C-G is described in ClinVar as [Likely_benign]. Clinvar id is 184332.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.
• BP7: Synonymous conserved (PhyloP=0.548 with no splicing effect.
• BS2: High AC in GnomAd4 at 35 AD gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
NF1	NM_001042492.3	c.7554C>G	p.Ala2518Ala	synonymous_variant	51/58	ENST00000358273.9	NP_001035957.1
NF1	NM_000267.3	c.7491C>G	p.Ala2497Ala	synonymous_variant	50/57		NP_000258.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.7554C>G	p.Ala2518Ala	synonymous_variant	51/58	1	NM_001042492.3	ENSP00000351015.4

Frequencies

GnomAD3 genomes AF: 0.000230 AC: 35 AN: 152164 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.000772

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.000131

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: 0.0000147

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.0000358 AC: 9 AN: 251408 Hom.: 0 AF XY: 0.0000294 AC XY: 4 AN XY: 135878

Gnomad AFR exome AF: 0.000554

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000253 AC: 37 AN: 1461840 Hom.: 0 Cov.: 32 AF XY: 0.0000220 AC XY: 16 AN XY: 727226

Gnomad4 AFR exome AF: 0.000956

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: 0.00

Gnomad4 OTH exome AF: 0.0000828

GnomAD4 genome AF: 0.000230 AC: 35 AN: 152164 Hom.: 0 Cov.: 32 AF XY: 0.000229 AC XY: 17 AN XY: 74330

Gnomad4 AFR AF: 0.000772

Gnomad4 AMR AF: 0.000131

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000147

Gnomad4 OTH AF: 0.00

Alfa AF: 0.000285 Hom.: 0

Bravo AF: 0.000261

ClinVar

Significance: Benign/Likely benign

Submissions summary: Benign:8

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Genetic Services Laboratory, University of Chicago	Dec 23, 2021	- -
Benign, criteria provided, single submitter	clinical testing	Women's Health and Genetics/Laboratory Corporation of America, LabCorp	Apr 30, 2018	Variant summary: NF1 c.7491C>G 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 observed variant frequency within African control individuals in the gnomAD database is approximately 3 fold above 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.7491C>G 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. Based on the evidence outlined above, the variant was classified as benign. -

Neurofibromatosis, type 1 Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Jan 29, 2024	- -
Benign, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Mar 15, 2022	- -

not provided Benign:2

Likely benign, criteria provided, single submitter	clinical testing	GeneDx	May 11, 2021	- -
Likely benign, criteria provided, single submitter	clinical testing	ARUP Laboratories, Molecular Genetics and Genomics, ARUP Laboratories	Oct 11, 2019	- -

Hereditary cancer-predisposing syndrome Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	Aug 25, 2014	Synonymous alterations with insufficient evidence to classify as benign -
Likely benign, criteria provided, single submitter	curation	Sema4, Sema4	Jun 19, 2021	- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.42
CADD	Benign	8.8
DANN	Benign	0.63
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.8

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		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: rs141897690; hg19: chr17-29679371;