17-31163263-C-G

Variant summary

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

The NM_001042492.3(NF1):c.366C>G(p.His122Gln) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. H122Y) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.334

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 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, NF1

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NF1	NM_001042492.3	c.366C>G	p.His122Gln	missense_variant	4/58	ENST00000358273.9
NF1	NM_000267.3	c.366C>G	p.His122Gln	missense_variant	4/57
NF1	NM_001128147.3	c.366C>G	p.His122Gln	missense_variant	4/15

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NF1	ENST00000358273.9	c.366C>G	p.His122Gln	missense_variant	4/58	1	NM_001042492.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Neurofibromatosis, type 1 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Mar 25, 2019

This variant is not present in population databases (ExAC no frequency). This sequence change replaces histidine with glutamine at codon 122 of the NF1 protein (p.His122Gln). The histidine residue is highly conserved and there is a small physicochemical difference between histidine and glutamine. This variant has not been reported in the literature in individuals with NF1-related conditions. 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. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site, but this prediction has not been confirmed by published transcriptional studies. Algorithms developed to predict the effect of missense changes on protein structure and function are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.55
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.080
Cadd	Benign	17
Dann	Benign	0.89
Eigen	Benign	-0.074
Eigen_PC	Benign	-0.13
FATHMM_MKL	Uncertain	0.88	D
LIST_S2	Uncertain	0.96	D;D;D;D
M_CAP	Pathogenic	0.65	D
MetaRNN	Uncertain	0.64	D;D;D;D
MetaSVM	Benign	-0.32	T
MutationAssessor	Uncertain	2.1	M;M;M;M
MutationTaster	Benign	0.95	D;D;D
PrimateAI	Pathogenic	0.86	D
Polyphen		0.96	D;D;D;.
Vest4		0.78, 0.79, 0.80
MutPred		0.34		Gain of helix (P = 0.0325);Gain of helix (P = 0.0325);Gain of helix (P = 0.0325);Gain of helix (P = 0.0325);
MVP		0.93
MPC		1.7
ClinPred		0.88	D
GERP RS		-2.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.13
gMVP		0.26

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs138952888; hg19: chr17-29490281;