17-31156101-C-T

Position:

• chr17-31156101-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 5P and 2B. PM1 PM2 PP2 BP4_Moderate

The NM_001042492.3(NF1):​c.179C>T​(p.Thr60Ile) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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 Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. T60A) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 32)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.29

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.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 13 uncertain in NM_001042492.3
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, NF1
• BP4: Computational evidence support a benign effect (MetaRNN=0.21571514).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
NF1	NM_001042492.3	c.179C>T	p.Thr60Ile	missense_variant	2/58	ENST00000358273.9
NF1	NM_000267.3	c.179C>T	p.Thr60Ile	missense_variant	2/57
NF1	NM_001128147.3	c.179C>T	p.Thr60Ile	missense_variant	2/15

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
NF1	ENST00000358273.9	c.179C>T	p.Thr60Ile	missense_variant	2/58	1	NM_001042492.3	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 04, 2020

The p.T60I variant (also known as c.179C>T), located in coding exon 2 of the NF1 gene, results from a C to T substitution at nucleotide position 179. The threonine at codon 60 is replaced by isoleucine, an amino acid with similar properties. This alteration has been reported with a carrier frequency of 0.0000 in 53 unselected men with breast cancer and 0.0001 in 12490 male controls (Momozawa Y et al. Nat Commun, 2018 10;9:4083). This amino acid position is not well conserved in available vertebrate species. In addition, this alteration is predicted to be tolerated by in silico analysis. 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	Uncertain	0.35
BayesDel_addAF	Benign	-0.14	T
BayesDel_noAF	Benign	-0.43
CADD	Benign	21
DANN	Benign	0.87
Eigen	Benign	0.080
Eigen_PC	Benign	0.20
FATHMM_MKL	Uncertain	0.85	D
LIST_S2	Uncertain	0.95	D;D;D;D
M_CAP	Benign	0.060	D
MetaRNN	Benign	0.22	T;T;T;T
MetaSVM	Benign	-1.1	T
MutationAssessor	Benign	1.4	L;L;L;L
MutationTaster	Benign	0.56	D;D;D
PrimateAI	Uncertain	0.73	T
Polyphen		0.51	P;B;B;.
Vest4		0.41, 0.38
MutPred		0.32		Gain of sheet (P = 0.0166);Gain of sheet (P = 0.0166);Gain of sheet (P = 0.0166);Gain of sheet (P = 0.0166);
MVP		0.39
MPC		0.75
ClinPred		0.66	D
GERP RS		3.9
Varity_R		0.070
gMVP		0.37

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

No publications associated with this variant yet.

Other links and lift over

hg19: chr17-29483119;