17-31163264-A-G

Position:

• chr17-31163264-A-G

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 1P and 3B. PP2 BP4_Moderate BS2_Supporting

The NM_001042492.3(NF1):​c.367A>G​(p.Thr123Ala) variant causes a missense change. The variant allele was found at a frequency of 0.00000867 in 1,614,004 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). Synonymous variant affecting the same amino acid position (i.e. T123T) has been classified as Likely benign.

• Frequency:
  • Genomes: 𝑓 0.000020 (0 hom., cov: 32)
  • Exomes 𝑓: 0.0000075 (0 hom.)
• Consequence: NF1 NM_001042492.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:5 B:1
• Conservation: PhyloP100: 5.43

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 (HGNC:):

ACMG classification

Verdict is Likely_benign. Variant got -2 ACMG points.

• 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=0.24034017).
• BS2: High AC in GnomAdExome4 at 11 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	Protein	UniProt
NF1	NM_001042492.3	c.367A>G	p.Thr123Ala	missense_variant	4/58	ENST00000358273.9	NP_001035957.1
NF1	NM_000267.3	c.367A>G	p.Thr123Ala	missense_variant	4/57		NP_000258.1
NF1	NM_001128147.3	c.367A>G	p.Thr123Ala	missense_variant	4/15		NP_001121619.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
NF1	ENST00000358273.9	c.367A>G	p.Thr123Ala	missense_variant	4/58	1	NM_001042492.3	ENSP00000351015.4

Frequencies

GnomAD3 genomes AF: 0.0000197 AC: 3 AN: 152182 Hom.: 0 Cov.: 32

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.00

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.0000441

Gnomad OTH AF: 0.00

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251312 Hom.: 0 AF XY: 0.00 AC XY: 0 AN XY: 135822

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000289

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: 0.00

GnomAD4 exome AF: 0.00000752 AC: 11 AN: 1461822 Hom.: 0 Cov.: 31 AF XY: 0.00000688 AC XY: 5 AN XY: 727208

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000224

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: 0.00000899

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome AF: 0.0000197 AC: 3 AN: 152182 Hom.: 0 Cov.: 32 AF XY: 0.0000135 AC XY: 1 AN XY: 74342

Gnomad4 AFR AF: 0.00

Gnomad4 AMR AF: 0.00

Gnomad4 ASJ AF: 0.00

Gnomad4 EAS AF: 0.00

Gnomad4 SAS AF: 0.00

Gnomad4 FIN AF: 0.00

Gnomad4 NFE AF: 0.0000441

Gnomad4 OTH AF: 0.00

Alfa AF: 0.0000712 Hom.: 0

Bravo AF: 0.00000378

ExAC AF: 0.00000824 AC: 1

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:5 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	Ambry Genetics	Mar 12, 2014	​The p.T123A variant (also known as c.367A>G), located in coding exon 4 of the NF1 gene, results from an A to G substitution at nucleotide position 367. The threonine at codon 123 is replaced by alanine, an amino acid with 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. To date, this alteration has been detected with an allele frequency of approximately 0.66% (greater than 150 alleles tested) in our clinical cohort (includes this individual). This amino acid position is well conserved in available vertebrate species. In addition, 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 of p.T123A remains unclear. -
Uncertain significance, criteria provided, single submitter	curation	Sema4, Sema4	Mar 11, 2022	- -

Neurofibromatosis, type 1 Uncertain:1 Benign:1

Uncertain significance, criteria provided, single submitter	clinical testing	Genome-Nilou Lab	Mar 15, 2022	- -
Benign, criteria provided, single submitter	clinical testing	Labcorp Genetics (formerly Invitae), Labcorp	Dec 11, 2023	- -

not provided Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

GeneDx

Apr 27, 2022

In silico analysis supports that this missense variant does not alter protein structure/function; Not observed in any cases, but was observed in the male controls in a breast cancer study (Momozawa 2018); This variant is associated with the following publications: (PMID: 30287823) -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Nov 09, 2022

The c.367A>G (p.T123A) alteration is located in exon 4 (coding exon 4) of the NF1 gene. This alteration results from a A to G substitution at nucleotide position 367, causing the threonine (T) at amino acid position 123 to be replaced by an alanine (A). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.10
BayesDel_addAF	Benign	-0.017	T
BayesDel_noAF	Benign	-0.18
CADD	Benign	22
DANN	Benign	0.91
DEOGEN2	Uncertain	0.55	.;D;.;.
Eigen	Benign	-0.013
Eigen_PC	Benign	0.13
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Benign	0.81	T;T;T;T
M_CAP	Uncertain	0.13	D
MetaRNN	Benign	0.24	T;T;T;T
MetaSVM	Benign	-0.55	T
MutationAssessor	Benign	1.6	L;L;L;L
PrimateAI	Uncertain	0.72	T
PROVEAN	Benign	-1.4	.;N;N;N
REVEL	Uncertain	0.33
Sift	Benign	0.36	.;T;T;T
Sift4G	Benign	0.32	.;T;T;T
Polyphen		0.36	B;B;B;.
Vest4		0.28, 0.30, 0.27
MutPred		0.29		Gain of helix (P = 0.0199);Gain of helix (P = 0.0199);Gain of helix (P = 0.0199);Gain of helix (P = 0.0199);
MVP		0.74
MPC		0.70
ClinPred		0.18	T
GERP RS		4.8
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.15
gMVP		0.30

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: rs587781757; hg19: chr17-29490282;