rs876660836

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM1PM2BP4_Moderate

The NM_001042492.3(NF1):​c.923C>G​(p.Ala308Gly) variant causes a missense change. The variant allele was found at a frequency of 0.000000684 in 1,461,820 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A308F) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

NF1
NM_001042492.3 missense

Scores

3
3
12

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5B:1

Conservation

PhyloP100: 5.49

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 2 ACMG points.

PM1
In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 35 uncertain in NM_001042492.3
PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.15838274).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
NF1NM_001042492.3 linkc.923C>G p.Ala308Gly missense_variant Exon 9 of 58 ENST00000358273.9 NP_001035957.1
NF1NM_000267.4 linkc.923C>G p.Ala308Gly missense_variant Exon 9 of 57 NP_000258.1
NF1NM_001128147.3 linkc.923C>G p.Ala308Gly missense_variant Exon 9 of 15 NP_001121619.1

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
NF1ENST00000358273.9 linkc.923C>G p.Ala308Gly missense_variant Exon 9 of 58 1 NM_001042492.3 ENSP00000351015.4

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461820
Hom.:
0
Cov.:
31
AF XY:
0.00
AC XY:
0
AN XY:
727216
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33478
American (AMR)
AF:
0.00
AC:
0
AN:
44724
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26130
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39674
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86258
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53410
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111984
Other (OTH)
AF:
0.00
AC:
0
AN:
60394
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.525
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<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
Cov.:
32

ClinVar

Significance: Conflicting classifications of pathogenicity
Submissions summary: Uncertain:5Benign:1
Revision: criteria provided, conflicting classifications
LINK: link

Submissions by phenotype

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

Dec 29, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Benign
Review Status:criteria provided, single submitter
Collection Method:clinical testing

not provided Uncertain:1
Apr 03, 2018
GeneDx
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This variant is denoted NF1 c.923C>G at the cDNA level, p.Ala308Gly (A308G) at the protein level, and results in the change of an Alanine to a Glycine (GCT>GGT). This variant has not, to our knowledge, been published in the literature as pathogenic or benign. NF1 Ala308Gly was observed at an allele frequency of 0.001% (1/111,666) in individuals of European ancestry in large population cohorts (Lek 2016). This variant is not located in a known functional domain. In silico analysis, which includes protein predictors and evolutionary conservation, supports that this variant does not alter protein structure/function. Based on currently available evidence, it is unclear whether NF1 Ala308Gly is a pathogenic or benign variant. We consider it to be a variant of uncertain significance.

Juvenile myelomonocytic leukemia Uncertain:1
Jun 05, 2023
Baylor Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

Hereditary cancer-predisposing syndrome;CN230736:Cardiovascular phenotype Uncertain:1
Oct 18, 2021
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The c.923C>G (p.A308G) alteration is located in exon 9 (coding exon 9) of the NF1 gene. This alteration results from a C to G substitution at nucleotide position 923, causing the alanine (A) at amino acid position 308 to be replaced by a glycine (G). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear.

Hereditary cancer-predisposing syndrome Uncertain:1
Sep 24, 2015
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.A308G variant (also known as c.923C>G), located in coding exon 9 of the NF1 gene, results from a C to G substitution at nucleotide position 923. The alanine at codon 308 is replaced by glycine, an amino acid with 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 0.002% (greater than55000alleles 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.A308G remains unclear.

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.12
BayesDel_addAF
Benign
-0.069
T
BayesDel_noAF
Benign
-0.34
CADD
Benign
22
DANN
Benign
0.95
DEOGEN2
Benign
0.0
.;T;.;.
Eigen
Benign
-0.20
Eigen_PC
Benign
0.040
FATHMM_MKL
Pathogenic
0.97
D
LIST_S2
Uncertain
0.92
D;D;D;D
M_CAP
Uncertain
0.12
D
MetaRNN
Benign
0.16
T;T;T;T
MetaSVM
Benign
-0.97
T
MutationAssessor
Benign
0.13
N;N;N;N
PhyloP100
5.5
PrimateAI
Uncertain
0.71
T
PROVEAN
Benign
0.0
.;N;N;N
REVEL
Benign
0.0
Sift
Pathogenic
0.0
.;T;T;T
Sift4G
Pathogenic
0.0
.;T;T;T
Vest4
0.0
ClinPred
0.43
T
GERP RS
5.2
PromoterAI
0.0056
Neutral
RBP_binding_hub_radar
0.0
RBP_regulation_power_radar
1.7
Varity_R
0.16
gMVP
0.18
Mutation Taster
=72/28
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: rs876660836; hg19: chr17-29527474; API