rs199474757

chr17-31214530-A-Gchr17-31214530-A-T

Variant summary

Our verdict is Uncertain significance. Variant got 1 ACMG points: 3P and 2B. PM1 PP2 BP4_Moderate

The NM_001042492.3(NF1):c.1472A>G(p.Tyr491Cys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000199 in 1,460,074 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. Y491N) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.000020 (0 hom.)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3 O:1
• Conservation: PhyloP100: 3.52

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 1 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 12 uncertain in NM_001042492.3
• PP2: Missense variant where missense usually causes diseases, NF1
• BP4: Computational evidence support a benign effect (MetaRNN=0.10623747).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NF1	NM_001042492.3	c.1472A>G	p.Tyr491Cys	missense_variant	13/58	ENST00000358273.9
NF1	NM_000267.3	c.1472A>G	p.Tyr491Cys	missense_variant	13/57
NF1	NM_001128147.3	c.1472A>G	p.Tyr491Cys	missense_variant	13/15

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NF1	ENST00000358273.9	c.1472A>G	p.Tyr491Cys	missense_variant	13/58	1	NM_001042492.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000798 AC: 2 AN: 250650 Hom.: 0 AF XY: 0.00000738 AC XY: 1 AN XY: 135566

Gnomad AFR exome AF: 0.0000618

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: 0.00000883

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.0000199 AC: 29 AN: 1460074 Hom.: 0 Cov.: 30 AF XY: 0.0000206 AC XY: 15 AN XY: 726466

Gnomad4 AFR exome AF: 0.0000299

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: 0.0000252

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:3 Other:1

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	Dec 07, 2023	This sequence change replaces tyrosine, which is neutral and polar, with cysteine, which is neutral and slightly polar, at codon 491 of the NF1 protein (p.Tyr491Cys). This variant is present in population databases (rs199474757, gnomAD 0.007%). This missense change has been observed in individual(s) with neurofibromatosis type I (PMID: 10712197). ClinVar contains an entry for this variant (Variation ID: 68300). 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 with a negative predictive value of 95%. 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. -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 28, 2022

The p.Y491C variant (also known as c.1472A>G), located in coding exon 13 of the NF1 gene, results from an A to G substitution at nucleotide position 1472. The tyrosine at codon 491 is replaced by cysteine, an amino acid with highly dissimilar properties. This variant was identified in two individuals with neurofibromatosis type 1 in a study of more than 500 neurofibromatosis type 1 probands (Fahsold R et al. Am. J. Hum. Genet., 2000 Mar;66:790-818). This amino acid position is not well 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. -

not provided Other:1

not provided, no classification provided

literature only

UniProtKB/Swiss-Prot

-

- -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.084
BayesDel_addAF	Benign	-0.17	T
BayesDel_noAF	Benign	-0.30
Cadd	Benign	19
Dann	Benign	0.97
Eigen	Benign	-0.39
Eigen_PC	Benign	-0.21
FATHMM_MKL	Uncertain	0.77	D
LIST_S2	Uncertain	0.90	D;D;D;D;D
M_CAP	Benign	0.037	D
MetaRNN	Benign	0.11	T;T;T;T;T
MetaSVM	Benign	-0.96	T
MutationAssessor	Benign	0.0	N;N;N;N;.
MutationTaster	Benign	0.98	N;N;N
PrimateAI	Uncertain	0.78	T
Polyphen		0.0	B;B;B;.;.
Vest4		0.72, 0.52, 0.43
MutPred		0.59		Gain of methylation at K490 (P = 0.0153);Gain of methylation at K490 (P = 0.0153);Gain of methylation at K490 (P = 0.0153);Gain of methylation at K490 (P = 0.0153);.;
MVP		0.78
MPC		0.86
ClinPred		0.071	T
GERP RS		3.0
Varity_R		0.056
gMVP		0.37

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: rs199474757; hg19: chr17-29541548; COSMIC: COSV62221625;