chr17-31181735-A-T

Variant names:

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM1PM2

The NM_001042492.3(NF1):c.680A>T(p.Tyr227Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000248 in 1,609,942 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. Y227H) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 32)

Exomes 𝑓: 0.0000021 ( 0 hom. )

Consequence

NF1
NM_001042492.3 missense

Scores

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:5

Conservation

PhyloP100: 8.37

Publications

0 publications found

Variant links:

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 Gene-Disease associations (from GenCC):

neurofibromatosis type 1
Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), ClinGen, PanelApp Australia, G2P, Genomics England PanelApp
neurofibromatosis-Noonan syndrome
Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp, PanelApp Australia
Moyamoya disease
Inheritance: AD Classification: MODERATE Submitted by: Genomics England PanelApp
hereditary pheochromocytoma-paraganglioma
Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
familial ovarian cancer
Inheritance: AD Classification: NO_KNOWN Submitted by: ClinGen

NF1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

PM1

In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 30 uncertain in NM_001042492.3

PM2

Very rare variant in population databases, with high coverage;

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NF1	NM_001042492.3 link	c.680A>T	p.Tyr227Phe	missense_variant	Exon 7 of 58	ENST00000358273.9	NP_001035957.1	P21359-1
NF1	NM_000267.4 link	c.680A>T	p.Tyr227Phe	missense_variant	Exon 7 of 57		NP_000258.1	P21359-2
NF1	NM_001128147.3 link	c.680A>T	p.Tyr227Phe	missense_variant	Exon 7 of 15		NP_001121619.1	P21359-5

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9 link	c.680A>T	p.Tyr227Phe	missense_variant	Exon 7 of 58	1	NM_001042492.3	ENSP00000351015.4		P21359-1

Frequencies

GnomAD3 genomes

AF:

0.00000658

AC:

AN:

152050

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.00

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

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

GnomAD4 exome

AF:

0.00000206

AC:

AN:

1457892

Hom.:

Cov.:

AF XY:

0.00000276

AC XY:

AN XY:

725518

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33434

American (AMR)

AF:

0.00

AC:

AN:

44720

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26070

East Asian (EAS)

AF:

0.00

AC:

AN:

39578

South Asian (SAS)

AF:

0.00

AC:

AN:

86180

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53410

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5716

European-Non Finnish (NFE)

AF:

0.00000271

AC:

AN:

1108528

Other (OTH)

AF:

0.00

AC:

AN:

60256

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.458

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.00000658

AC:

AN:

152050

Hom.:

Cov.:

AF XY:

0.00

AC XY:

AN XY:

74264

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

41434

American (AMR)

AF:

0.00

AC:

AN:

15256

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3466

East Asian (EAS)

AF:

0.00

AC:

AN:

5188

South Asian (SAS)

AF:

0.00

AC:

AN:

4838

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10556

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000147

AC:

AN:

67998

Other (OTH)

AF:

0.00

AC:

AN:

2086

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.425

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Alfa

AF:

0.00

Hom.:

Bravo

AF:

0.00000378

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:5

Revision: criteria provided, multiple submitters, no conflicts

LINK: link

Submissions by phenotype

Neurofibromatosis, type 1

Uncertain:2

Mar 15, 2022

Genome-Nilou Lab

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

- -

Jan 13, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

This sequence change replaces tyrosine, which is neutral and polar, with phenylalanine, which is neutral and non-polar, at codon 227 of the NF1 protein (p.Tyr227Phe). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with NF1-related conditions. ClinVar contains an entry for this variant (Variation ID: 480216). Invitae Evidence Modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) has been performed for this missense variant. However, the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on 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. -

NF1-related disorder

Uncertain:1

Aug 19, 2024

PreventionGenetics, part of Exact Sciences

Significance:Uncertain significance

Review Status:no assertion criteria provided

Collection Method:clinical testing

The NF1 c.680A>T variant is predicted to result in the amino acid substitution p.Tyr227Phe. To our knowledge, this variant has not been reported in the literature or in a large population database, indicating this variant is rare. This variant is interpreted as uncertain in ClinVar (https://www.ncbi.nlm.nih.gov/clinvar/variation/480216/). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

not provided

Uncertain:1

Jun 12, 2020

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Not observed in large population cohorts (Lek 2016); In silico analysis supports that this missense variant has a deleterious effect on protein structure/function; Has not been previously published as pathogenic or benign to our knowledge -

Hereditary cancer-predisposing syndrome;CN230736:Cardiovascular phenotype

Uncertain:1

Jan 08, 2024

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.Y227F variant (also known as c.680A>T), located in coding exon 7 of the NF1 gene, results from an A to T substitution at nucleotide position 680. The tyrosine at codon 227 is replaced by phenylalanine, an amino acid with highly similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. 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

0.25

BayesDel_addAF

Pathogenic

0.21

BayesDel_noAF

Uncertain

0.060

CADD

Uncertain

(source)

DANN

Uncertain

0.99

DEOGEN2

Pathogenic

0.80

.;D;.;.;.

Eigen

Uncertain

0.53

Eigen_PC

Uncertain

0.59

FATHMM_MKL

Uncertain

0.97

LIST_S2

Uncertain

0.96

D;D;D;D;D

M_CAP

Pathogenic

0.54

MetaRNN

Uncertain

0.68

D;D;D;D;D

MetaSVM

Uncertain

0.25

MutationAssessor

Benign

1.9

L;L;L;L;.

PhyloP100

8.4

PrimateAI

Pathogenic

0.83

PROVEAN

Uncertain

-2.8

.;D;D;D;.

REVEL

Uncertain

0.58

Sift

Uncertain

0.0030

.;D;D;T;.

Sift4G

Benign

0.20

.;T;T;D;.

Polyphen

0.97

D;P;D;.;.

Vest4

0.51, 0.51, 0.57

MutPred

0.57

Gain of helix (P = 0.2294);Gain of helix (P = 0.2294);Gain of helix (P = 0.2294);Gain of helix (P = 0.2294);.;

MVP

0.85

MPC

1.5

ClinPred

0.96

GERP RS

5.9

PromoterAI

-0.0075

Neutral

(source)

Varity_R

0.46

gMVP

0.40

Mutation Taster

=51/49

polymorphism

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over