chr17-31229091-A-G

Position:

• chr17-31229091-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 3P and 3B. PM2 PP2 BP4_Moderate BP6

The NM_001042492.3(NF1):​c.2476A>G​(p.Ile826Val) variant causes a missense change. The variant allele was found at a frequency of 0.000000685 in 1,459,566 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). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I826L) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 5.22

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), NF1. . Gene score misZ 6.5427 (greater than the threshold 3.09). Trascript score misZ 8.4054 (greater than threshold 3.09). GenCC has associacion of gene with 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=0.10236812).
• BP6: Variant 17-31229091-A-G is Benign according to our data. Variant chr17-31229091-A-G is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 527562.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=1, Likely_benign=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NF1	NM_001042492.3	c.2476A>G	p.Ile826Val	missense_variant	21/58	ENST00000358273.9
NF1	NM_000267.3	c.2476A>G	p.Ile826Val	missense_variant	21/57

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NF1	ENST00000358273.9	c.2476A>G	p.Ile826Val	missense_variant	21/58	1	NM_001042492.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.00000399 AC: 1 AN: 250316 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135404

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: 0.0000462

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.85e-7 AC: 1 AN: 1459566 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 726092

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: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Neurofibromatosis, type 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Feb 16, 2023

This sequence change replaces isoleucine, which is neutral and non-polar, with valine, which is neutral and non-polar, at codon 826 of the NF1 protein (p.Ile826Val). This variant is present in population databases (rs767069721, gnomAD 0.004%). 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: 527562). 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. 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 Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 14, 2024

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	0.076
BayesDel_addAF	Benign	-0.22	T
BayesDel_noAF	Benign	-0.55
CADD	Benign	21
DANN	Uncertain	0.98
DEOGEN2	Benign	0.41	T;.;T
Eigen	Benign	-0.32
Eigen_PC	Benign	-0.038
FATHMM_MKL	Pathogenic	1.0	D
LIST_S2	Uncertain	0.93	D;D;D
M_CAP	Benign	0.037	D
MetaRNN	Benign	0.10	T;T;T
MetaSVM	Benign	-0.97	T
MutationAssessor	Benign	-0.20	N;N;.
MutationTaster	Benign	0.99	D;D
PrimateAI	Uncertain	0.71	T
PROVEAN	Benign	-0.28	N;N;N
REVEL	Benign	0.16
Sift	Benign	1.0	T;T;T
Sift4G	Benign	0.31	T;T;T
Polyphen		0.0	B;B;.
Vest4		0.39
MutPred		0.23		Gain of sheet (P = 0.0827);Gain of sheet (P = 0.0827);.;
MVP		0.29
MPC		0.57
ClinPred		0.36	T
GERP RS		5.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.8
Varity_R		0.097
gMVP		0.19

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

Other links and lift over

dbSNP: rs767069721; hg19: chr17-29556109;