rs772995929

Positions:

• chr17-31156022-G-A
• chr17-31156022-G-T

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 3P and 4B. PM1 PP2 BP4_Moderate BP6 BS2_Supporting

The NM_001042492.3(NF1):​c.100G>A​(p.Val34Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000616 in 1,461,376 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/21 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. V34A) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000062 (0 hom.)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3 B:2
• Conservation: PhyloP100: 7.58

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 Likely_benign. Variant got -1 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 15 uncertain in NM_001042492.3
• 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=0.11663583).
• BP6: Variant 17-31156022-G-A is Benign according to our data. Variant chr17-31156022-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 186105.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=3, Benign=1}.
• BS2: High AC in GnomAdExome4 at 9 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/exons	MANE	UniProt
NF1	NM_001042492.3	c.100G>A	p.Val34Ile	missense_variant	2/58	ENST00000358273.9
NF1	NM_000267.3	c.100G>A	p.Val34Ile	missense_variant	2/57
NF1	NM_001128147.3	c.100G>A	p.Val34Ile	missense_variant	2/15

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NF1	ENST00000358273.9	c.100G>A	p.Val34Ile	missense_variant	2/58	1	NM_001042492.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000319 AC: 8 AN: 250870 Hom.: 0 AF XY: 0.0000221 AC XY: 3 AN XY: 135594

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000174

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: 0.00

Gnomad OTH exome AF: 0.000327

GnomAD4 exome AF: 0.00000616 AC: 9 AN: 1461376 Hom.: 0 Cov.: 33 AF XY: 0.00000550 AC XY: 4 AN XY: 727014

Gnomad4 AFR exome AF: 0.0000299

Gnomad4 AMR exome AF: 0.000157

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: 0.00

Gnomad4 OTH exome AF: 0.0000166

GnomAD4 genome Cov.: 32

ExAC AF: 0.0000247 AC: 3

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Neurofibromatosis, type 1 Uncertain:1 Benign:1

Likely benign, criteria provided, single submitter	clinical testing	Invitae	Dec 22, 2023	- -
Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Mar 15, 2022	- -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Fulgent Genetics, Fulgent Genetics

Feb 03, 2022

- -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 30, 2015

The p.V34I variant (also known as c.100G>A), located in coding exon 2 of the NF1 gene, results from a G to A substitution at nucleotide position 100. The valine at codon 34 is replaced by isoleucine, 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 0.001% (greater than 55000 alleles tested) in our clinical cohort.This amino acid position is highly conserved in available vertebrate species. However, this alteration is predicted to be benign and tolerated by PolyPhen and SIFT in silico analyses, respectively.Since supporting evidence is limited at this time, the clinical significance ofp.V34Iremains unclear. -

Hereditary cancer-predisposing syndrome;CN230736:Cardiovascular phenotype Benign:1

Benign, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 30, 2023

This alteration is classified as 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	0.079
BayesDel_addAF	Benign	-0.29	T
BayesDel_noAF	Benign	-0.43
CADD	Benign	22
DANN	Benign	0.96
DEOGEN2	Benign	0.40	.;T;.;.
Eigen	Benign	0.15
Eigen_PC	Uncertain	0.28
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Uncertain	0.93	D;D;D;D
M_CAP	Benign	0.065	D
MetaRNN	Benign	0.12	T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	0.90	L;L;L;L
MutationTaster	Benign	1.0	D;D;D
PrimateAI	Uncertain	0.76	T
PROVEAN	Benign	-0.36	.;N;N;N
REVEL	Benign	0.17
Sift	Benign	0.73	.;T;T;T
Sift4G	Benign	0.39	.;T;T;T
Polyphen		0.90	P;B;P;.
Vest4		0.30, 0.29, 0.27
MutPred		0.071		Loss of methylation at K33 (P = 0.0818);Loss of methylation at K33 (P = 0.0818);Loss of methylation at K33 (P = 0.0818);Loss of methylation at K33 (P = 0.0818);
MVP		0.42
MPC		0.56
ClinPred		0.18	T
GERP RS		5.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.10
gMVP		0.28

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: rs772995929; hg19: chr17-29483040;