rs1555533342

chr17-31326004-G-Achr17-31326004-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP2

The NM_001042492.3(NF1):c.5020G>A(p.Val1674Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000274 in 1,461,890 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★). Synonymous variant affecting the same amino acid position (i.e. V1674V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000027 (0 hom.)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:4
• Conservation: PhyloP100: 9.56

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 5 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 12 uncertain in NM_001042492.3
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, NF1

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NF1	NM_001042492.3	c.5020G>A	p.Val1674Ile	missense_variant	37/58	ENST00000358273.9
NF1	NM_000267.3	c.4957G>A	p.Val1653Ile	missense_variant	36/57

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NF1	ENST00000358273.9	c.5020G>A	p.Val1674Ile	missense_variant	37/58	1	NM_001042492.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000274 AC: 4 AN: 1461890 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 727248

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00000270

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Neurofibromatosis, type 1 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Mar 15, 2022	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Invitae	Oct 05, 2023	This sequence change replaces valine, which is neutral and non-polar, with isoleucine, which is neutral and non-polar, at codon 1653 of the NF1 protein (p.Val1653Ile). This variant is not present in population databases (gnomAD no frequency). This missense change has been observed in individuals with NF1-related conditions (PMID: 30308447; Invitae). This variant is also known as p.Val1674Ile. ClinVar contains an entry for this variant (Variation ID: 485969). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt NF1 protein function. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Microcephaly Uncertain:1

Uncertain significance, no assertion criteria provided

research

Department of Pediatrics, Samsung Medical Center, Samsung Medical Center

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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Aug 31, 2020

The p.V1653I variant (also known as c.4957G>A), located in coding exon 36 of the NF1 gene, results from a G to A substitution at nucleotide position 4957. The valine at codon 1653 is replaced by isoleucine, an amino acid with highly similar properties. This amino acid change (designated as p.Val1674Ile) has been identified in one individual with features suggestive of NF1 as well as an affected family member (Tsipi M et al. J. Neurol. Sci., 2018 12;395:95-105). This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.082
BayesDel_addAF	Benign	-0.00061	T
BayesDel_noAF	Benign	-0.24
Cadd	Uncertain	25
Dann	Uncertain	1.0
DEOGEN2	Benign	0.37	T;.;T
Eigen	Benign	0.13
Eigen_PC	Uncertain	0.37
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.88	D;D;D
M_CAP	Pathogenic	0.36	D
MetaRNN	Uncertain	0.55	D;D;D
MetaSVM	Benign	-0.78	T
MutationAssessor	Benign	-0.34	N;.;.
MutationTaster	Benign	1.0	D;D
PrimateAI	Uncertain	0.74	T
PROVEAN	Benign	-0.10	N;N;N
REVEL	Benign	0.20
Sift	Benign	0.65	T;T;T
Sift4G	Benign	0.55	T;T;T
Polyphen		0.15	B;D;.
Vest4		0.52
MutPred		0.67		Gain of helix (P = 0.2684);.;.;
MVP		0.59
MPC		1.5
ClinPred		0.91	D
GERP RS		5.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.25
gMVP		0.33

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: rs1555533342; hg19: chr17-29653022;