rs779063198

Variant summary

Our verdict is Likely benign. The variant received -1 ACMG points: 0P and 1B. BS2_Supporting

The NM_001042492.3(NF1):​c.203T>C​(p.Met68Thr) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000753 in 1,461,414 control chromosomes in the GnomAD database, with no homozygous occurrence. 3/3 splice prediction tools predict no significant impact on normal splicing. 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. M68I) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 0.0000075 ( 0 hom. )

Consequence

NF1
NM_001042492.3 missense, splice_region

Scores

3
11
5
Splicing: ADA: 0.02960
2

Clinical Significance

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

Conservation

PhyloP100: 7.54

Publications

3 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: Likely_benign. The variant received -1 ACMG points.

BS2
High AC in GnomAdExome4 at 11 AD gene. Variant has AC lower than other variant known as pathogenic in the gene, so the strength is limited to Supporting.

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
NF1NM_001042492.3 linkc.203T>C p.Met68Thr missense_variant, splice_region_variant Exon 2 of 58 ENST00000358273.9 NP_001035957.1 P21359-1
NF1NM_000267.4 linkc.203T>C p.Met68Thr missense_variant, splice_region_variant Exon 2 of 57 NP_000258.1 P21359-2
NF1NM_001128147.3 linkc.203T>C p.Met68Thr missense_variant, splice_region_variant Exon 2 of 15 NP_001121619.1 P21359-5

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
NF1ENST00000358273.9 linkc.203T>C p.Met68Thr missense_variant, splice_region_variant Exon 2 of 58 1 NM_001042492.3 ENSP00000351015.4 P21359-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD2 exomes
AF:
0.00000398
AC:
1
AN:
251234
AF XY:
0.00000736
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000880
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.00000753
AC:
11
AN:
1461414
Hom.:
0
Cov.:
32
AF XY:
0.00000688
AC XY:
5
AN XY:
727036
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33462
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26120
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39604
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86240
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53406
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5706
European-Non Finnish (NFE)
AF:
0.00000810
AC:
9
AN:
1111776
Other (OTH)
AF:
0.0000331
AC:
2
AN:
60378
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.489
Heterozygous variant carriers
0
1
1
2
2
3
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
ExAC
AF:
0.00000824
AC:
1
EpiCase
AF:
0.00
EpiControl
AF:
0.0000593

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
Jan 22, 2025
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces methionine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 68 of the NF1 protein (p.Met68Thr). This variant is present in population databases (rs779063198, gnomAD 0.0009%). 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: 457559). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. 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
Dec 02, 2019
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.M68T variant (also known as c.203T>C), located in coding exon 2 of the NF1 gene, results from a T to C substitution at nucleotide position 203. The methionine at codon 68 is replaced by threonine, an amino acid with 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
Pathogenic
0.84
BayesDel_addAF
Pathogenic
0.21
D
BayesDel_noAF
Uncertain
0.060
CADD
Benign
23
DANN
Benign
0.89
DEOGEN2
Uncertain
0.63
.;D;.;.
Eigen
Uncertain
0.33
Eigen_PC
Uncertain
0.39
FATHMM_MKL
Uncertain
0.97
D
LIST_S2
Uncertain
0.89
D;D;D;D
M_CAP
Uncertain
0.28
D
MetaRNN
Uncertain
0.58
D;D;D;D
MetaSVM
Benign
-1.1
T
MutationAssessor
Uncertain
2.1
M;M;M;M
PhyloP100
7.5
PrimateAI
Pathogenic
0.93
D
PROVEAN
Benign
-2.2
.;N;N;D
REVEL
Uncertain
0.43
Sift
Benign
0.12
.;T;T;D
Sift4G
Uncertain
0.0090
.;D;D;D
Polyphen
0.81
P;B;P;.
Vest4
0.88, 0.90, 0.94
MutPred
0.38
Loss of stability (P = 0.028);Loss of stability (P = 0.028);Loss of stability (P = 0.028);Loss of stability (P = 0.028);
MVP
0.78
MPC
1.5
ClinPred
0.73
D
GERP RS
5.0
Varity_R
0.40
gMVP
0.61
Mutation Taster
=35/65
disease causing

Splicing

Name
Calibrated prediction
Score
Prediction
dbscSNV1_ADA
Benign
0.030
dbscSNV1_RF
Benign
0.14
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

Other links and lift over

dbSNP: rs779063198; hg19: chr17-29483143; API