NM_001042492.3:c.8238T>G

Variant summary

Our verdict is Likely benign. Variant got -6 ACMG points: 1P and 7B. PP2BP4_ModerateBP6BS2

The NM_001042492.3(NF1):​c.8238T>G​(p.Ile2746Met) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000458 in 1,461,854 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars).

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.000046 ( 0 hom. )

Consequence

NF1
NM_001042492.3 missense

Scores

7
12

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:2

Conservation

PhyloP100: 0.512
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]

Genome browser will be placed here

ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -6 ACMG points.

PP2
Missense variant in the NF1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 399 curated pathogenic missense variants (we use a threshold of 10). The gene has 143 curated benign missense variants. Gene score misZ: 6.5427 (above the threshold of 3.09). Trascript score misZ: 8.4054 (above the threshold of 3.09). GenCC associations: The gene is linked to neurofibromatosis, familial spinal, hereditary pheochromocytoma-paraganglioma, neurofibromatosis type 1, Watson syndrome, neurofibromatosis-Noonan syndrome, Moyamoya disease, familial ovarian cancer.
BP4
Computational evidence support a benign effect (MetaRNN=0.17146406).
BP6
Variant 17-31360564-T-G is Benign according to our data. Variant chr17-31360564-T-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 231655.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Benign=1, Uncertain_significance=4}.
BS2
High AC in GnomAdExome4 at 67 AD gene.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
NF1NM_001042492.3 linkc.8238T>G p.Ile2746Met missense_variant Exon 57 of 58 ENST00000358273.9 NP_001035957.1 P21359-1
NF1NM_000267.3 linkc.8175T>G p.Ile2725Met missense_variant Exon 56 of 57 NP_000258.1 P21359-2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
NF1ENST00000358273.9 linkc.8238T>G p.Ile2746Met missense_variant Exon 57 of 58 1 NM_001042492.3 ENSP00000351015.4 P21359-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD3 exomes
AF:
0.00000795
AC:
2
AN:
251440
Hom.:
0
AF XY:
0.0000147
AC XY:
2
AN XY:
135888
show subpopulations
Gnomad AFR exome
AF:
0.00
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:
0.0000176
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000458
AC:
67
AN:
1461854
Hom.:
0
Cov.:
31
AF XY:
0.0000468
AC XY:
34
AN XY:
727224
show subpopulations
Gnomad4 AFR exome
AF:
0.00
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:
0.0000585
Gnomad4 OTH exome
AF:
0.0000331
GnomAD4 genome
Cov.:
32
TwinsUK
AF:
0.000539
AC:
2
ALSPAC
AF:
0.00
AC:
0
ExAC
AF:
0.00000824
AC:
1

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:5Benign:2
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

Neurofibromatosis, type 1 Uncertain:2Benign:1
Mar 15, 2022
Genome-Nilou Lab
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Apr 01, 2021
Johns Hopkins Genomics, Johns Hopkins University
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

NF1 c.8238T>G (rs779789452) is rare (<0.1%) in a large population dataset (gnomAD: 2/251440 total alleles; 0.0008%; no homozygotes) and has not been reported in the literature, to our knowledge. This variant has been reported in ClinVar (Variation ID: 231655). Three bioinformatic tools queried predict that this substitution would be tolerated, however the isoleucine residue at this position is evolutionarily conserved across most species assessed. We consider the clinical significance of NF1 c.8238T>G to be uncertain at this time. -

Dec 16, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance: Benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

NF1-related disorder Uncertain:1
Jun 03, 2024
PreventionGenetics, part of Exact Sciences
Significance: Uncertain significance
Review Status: no assertion criteria provided
Collection Method: clinical testing

The NF1 c.8238T>G variant is predicted to result in the amino acid substitution p.Ile2746Met. To our knowledge, this variant has not been reported in the literature. This variant is reported in 2 of 251,000 alleles in gnomAD. It has conflicting interpretations of likely benign and uncertain significance in ClinVar (https://preview.ncbi.nlm.nih.gov/clinvar/variation/231655/). At this time, the clinical significance of this variant is uncertain due to the absence of conclusive functional and genetic evidence. -

Neurofibromatosis, type 1;C0349639:Juvenile myelomonocytic leukemia;C0553586:Café-au-lait macules with pulmonary stenosis;C1834235:Neurofibromatosis, familial spinal;C2931482:Neurofibromatosis-Noonan syndrome Uncertain:1
Aug 18, 2021
Fulgent Genetics, Fulgent Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

- -

Hereditary cancer-predisposing syndrome Uncertain:1
Dec 13, 2015
Ambry Genetics
Significance: Uncertain significance
Review Status: criteria provided, single submitter
Collection Method: clinical testing

The p.I2746M variant (also known as c.8238T>G), located in coding exon 57 of the NF1 gene, results from a T to G substitution at nucleotide position 8238. The isoleucine at codon 2746 is replaced by methionine, an amino acid with highly similar properties. This variant was not reported in population based cohorts in the following databases: Database of Single Nucleotide Polymorphisms (dbSNP), NHLBI Exome Sequencing Project (ESP), and 1000 Genomes Project. In the ESP, this variant was not observed in 6503 samples (13006 alleles) with coverage at this position. To date, this alteration has been detected with an allele frequency of approximately 0.003% (greater than 110000 alleles tested) in our clinical cohort. This amino acid position is 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 p.I2746M remains unclear. -

Hereditary cancer-predisposing syndrome;CN230736:Cardiovascular phenotype Benign:1
Jan 04, 2023
Ambry Genetics
Significance: Likely benign
Review Status: criteria provided, single submitter
Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, 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. -

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.062
BayesDel_addAF
Benign
-0.21
T
BayesDel_noAF
Benign
-0.53
CADD
Benign
23
DANN
Uncertain
1.0
DEOGEN2
Uncertain
0.45
T;.;T
Eigen
Benign
0.17
Eigen_PC
Uncertain
0.24
FATHMM_MKL
Uncertain
0.89
D
LIST_S2
Uncertain
0.91
D;D;D
M_CAP
Uncertain
0.086
D
MetaRNN
Benign
0.17
T;T;T
MetaSVM
Benign
-0.99
T
MutationAssessor
Benign
1.2
L;.;.
PrimateAI
Uncertain
0.73
T
PROVEAN
Benign
-0.89
N;N;N
REVEL
Benign
0.040
Sift
Benign
0.20
T;T;T
Sift4G
Benign
0.070
T;T;T
Polyphen
0.68
P;P;.
Vest4
0.28
MutPred
0.24
Gain of phosphorylation at Y2742 (P = 0.0775);.;.;
MVP
0.46
MPC
0.91
ClinPred
0.43
T
GERP RS
4.0
Varity_R
0.11
gMVP
0.14

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

Below is the list of publications found by LitVar. It may be empty.

Other links and lift over

dbSNP: rs779789452; hg19: chr17-29687582; API