chr17-31232879-T-A

Variant names:

• chr17-31232879-T-A
• rs786204211
• NM_001042492.3:c.3494T>A

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PM1 PM2 PM5 PP3_Strong PP5_Moderate

The NM_001042492.3(NF1):​c.3494T>A​(p.Ile1165Lys) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 3/3 splice prediction tools predict no significant impact on normal splicing. Variant has been reported in ClinVar as Pathogenic (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I1165T) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 31)
• Consequence: NF1 NM_001042492.3 missense, splice_region
• Scores: Splicing: ADA: 0.4981
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 7.62
• Publications: 0 publications found

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

ACMG classification

Our verdict: Pathogenic. The variant received 12 ACMG points.

• PM1: In a hotspot region, there are 9 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 2 benign, 38 uncertain in NM_001042492.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr17-31232879-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 955671.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.96
• PP5: Variant 17-31232879-T-A is Pathogenic according to our data. Variant chr17-31232879-T-A is described in ClinVar as Pathogenic. ClinVar VariationId is 188312.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
NF1	NM_001042492.3	c.3494T>A	p.Ile1165Lys	missense_variant, splice_region_variant	Exon 26 of 58	ENST00000358273.9	NP_001035957.1
NF1	NM_000267.4	c.3494T>A	p.Ile1165Lys	missense_variant, splice_region_variant	Exon 26 of 57		NP_000258.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.3494T>A	p.Ile1165Lys	missense_variant, splice_region_variant	Exon 26 of 58	1	NM_001042492.3	ENSP00000351015.4

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Neurofibromatosis, type 1 Pathogenic:1

Jan 20, 2018

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

A different missense substitution at this codon (p.Ile1165Thr) has been reported in several individuals affected with neurofibromatosis, type 1 (PMID: 23656349, 21520333). For these reasons, this variant has been classified as Pathogenic. Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has been reported to be de novo in an individual affected with neurofibromatosis, type 1 (Invitae). ClinVar contains an entry for this variant (Variation ID: 188312). This variant is not present in population databases (ExAC no frequency). This sequence change replaces isoleucine with lysine at codon 1165 of the NF1 protein (p.Ile1165Lys). The isoleucine residue is moderately conserved and there is a moderate physicochemical difference between isoleucine and lysine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.23	D
BayesDel_noAF	Uncertain	0.10
CADD	Pathogenic	27
DANN	Benign	0.96
DEOGEN2	Pathogenic	0.94	D;.;T
Eigen	Pathogenic	0.75
Eigen_PC	Pathogenic	0.74
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.93	D;D;D
M_CAP	Pathogenic	0.96	D
MetaRNN	Pathogenic	0.96	D;D;D
MetaSVM	Benign	-1.0	T
MutationAssessor	Uncertain	2.5	M;M;.
PhyloP100		7.6
PrimateAI	Pathogenic	0.86	D
PROVEAN	Pathogenic	-5.1	D;D;D
REVEL	Pathogenic	0.82
Sift	Pathogenic	0.0	D;D;D
Sift4G	Pathogenic	0.0010	D;D;D
Polyphen		0.99	D;D;.
Vest4		0.98
MutPred		0.83		Gain of disorder (P = 0.0018);Gain of disorder (P = 0.0018);.;
MVP		0.91
MPC		2.2
ClinPred		1.0	D
GERP RS		5.5
Varity_R		0.81
gMVP		0.97
Mutation Taster		=0/100	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.50
dbscSNV1_RF	Benign	0.65
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

Other links and lift over

dbSNP: rs786204211; hg19: chr17-29559897;