17-31232768-G-C

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2BP4_Moderate

The NM_001042492.3(NF1):​c.3383G>C​(p.Gly1128Ala) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,864 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/22 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. G1128D) has been classified as Likely benign.

Frequency

Genomes: not found (cov: 31)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

NF1
NM_001042492.3 missense

Scores

1
3
15

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:2

Conservation

PhyloP100: 6.02

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

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 0 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.24746925).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
NF1NM_001042492.3 linkc.3383G>C p.Gly1128Ala missense_variant Exon 26 of 58 ENST00000358273.9 NP_001035957.1 P21359-1
NF1NM_000267.4 linkc.3383G>C p.Gly1128Ala missense_variant Exon 26 of 57 NP_000258.1 P21359-2

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
NF1ENST00000358273.9 linkc.3383G>C p.Gly1128Ala missense_variant Exon 26 of 58 1 NM_001042492.3 ENSP00000351015.4 P21359-1

Frequencies

GnomAD3 genomes
Cov.:
31
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461864
Hom.:
0
Cov.:
32
AF XY:
0.00000138
AC XY:
1
AN XY:
727238
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26136
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39700
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53414
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111988
Other (OTH)
AF:
0.00
AC:
0
AN:
60396
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
GnomAD4 genome
Cov.:
31

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:2
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Neurofibromatosis, type 1 Uncertain:1
Dec 08, 2023
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces glycine, which is neutral and non-polar, with alanine, which is neutral and non-polar, at codon 1128 of the NF1 protein (p.Gly1128Ala). 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: 485975). 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
Apr 07, 2021
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.G1128A variant (also known as c.3383G>C), located in coding exon 26 of the NF1 gene, results from a G to C substitution at nucleotide position 3383. The glycine at codon 1128 is replaced by alanine, an amino acid with similar properties. 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
0.068
BayesDel_addAF
Benign
0.011
T
BayesDel_noAF
Benign
-0.22
CADD
Benign
22
DANN
Benign
0.66
DEOGEN2
Uncertain
0.52
D;.;T
Eigen
Benign
0.010
Eigen_PC
Benign
0.21
FATHMM_MKL
Pathogenic
0.98
D
LIST_S2
Uncertain
0.95
D;D;D
M_CAP
Benign
0.060
D
MetaRNN
Benign
0.25
T;T;T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
0.0
N;N;.
PhyloP100
6.0
PrimateAI
Uncertain
0.70
T
PROVEAN
Benign
-1.4
N;N;N
REVEL
Benign
0.21
Sift
Benign
0.87
T;T;T
Sift4G
Benign
0.74
T;T;T
Polyphen
0.0010
B;B;.
Vest4
0.36
MutPred
0.19
Gain of helix (P = 0.0425);Gain of helix (P = 0.0425);.;
MVP
0.81
MPC
0.75
ClinPred
0.88
D
GERP RS
5.5
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.8
Varity_R
0.21
gMVP
0.26
Mutation Taster
=54/46
polymorphism

Splicing

Name
Calibrated prediction
Score
Prediction
SpliceAI score (max)
0.040
Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

Other links and lift over

dbSNP: rs1060500325; hg19: chr17-29559786; API