17-31225126-T-C

Variant names:

• chr17-31225126-T-C
• rs752591958
• NM_001042492.3:c.1877T>C

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The ENST00000358273.9(NF1):​c.1877T>C​(p.Leu626Pro) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,354 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: NF1 ENST00000358273.9 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:3
• Conservation: PhyloP100: 0.460
• Publications: 4 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: Uncertain_significance. The variant received 2 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 9 benign, 28 uncertain in ENST00000358273.9
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.20654994).

Variant Effect in Transcripts

ACMG analysis was done for transcript: ENST00000358273.9. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NF1	NM_001042492.3	MANE Select	c.1877T>C	p.Leu626Pro	missense	Exon 17 of 58	NP_001035957.1
	NF1	NM_000267.4		c.1877T>C	p.Leu626Pro	missense	Exon 17 of 57	NP_000258.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NF1	ENST00000358273.9	TSL:1 MANE Select	c.1877T>C	p.Leu626Pro	missense	Exon 17 of 58	ENSP00000351015.4
	NF1	ENST00000356175.7	TSL:1	c.1877T>C	p.Leu626Pro	missense	Exon 17 of 57	ENSP00000348498.3
	NF1	ENST00000579081.6	TSL:1	n.1877T>C		non_coding_transcript_exon	Exon 17 of 58	ENSP00000462408.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD2 exomes AF: 0.00000398 AC: 1 AN: 251192 AF XY: 0.00

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000881

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461354 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727012

⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 33444

American (AMR) AF: 0.00 AC: 0 AN: 44722

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26116

East Asian (EAS) AF: 0.00 AC: 0 AN: 39666

South Asian (SAS) AF: 0.00 AC: 0 AN: 86250

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53372

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111648

Other (OTH) AF: 0.00 AC: 0 AN: 60370

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.00233887), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ExAC AF: 0.00000824 AC: 1

ClinVar

ClinVar submissions as Germline

Significance: Uncertain significance

Revision: criteria provided, multiple submitters, no conflicts

Pathogenic	VUS	Benign	Condition
-	2	-	Neurofibromatosis, type 1 (2)
-	1	-	Hereditary cancer-predisposing syndrome;CN230736:Cardiovascular phenotype (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Benign	-0.042	T
BayesDel_noAF	Benign	-0.30
CADD	Benign	17
DANN	Benign	0.96
DEOGEN2	Uncertain	0.54	D
Eigen	Benign	-0.61
Eigen_PC	Benign	-0.53
FATHMM_MKL	Uncertain	0.86	D
LIST_S2	Benign	0.83	T
M_CAP	Benign	0.059	D
MetaRNN	Benign	0.21	T
MetaSVM	Benign	-0.97	T
MutationAssessor	Benign	0.0	N
PhyloP100		0.46
PrimateAI	Benign	0.36	T
PROVEAN	Benign	-1.3	N
REVEL	Benign	0.18
Sift	Uncertain	0.0070	D
Sift4G	Uncertain	0.0040	D
Polyphen		0.19	B
Vest4		0.82
MutPred		0.53		Loss of sheet (P = 0.0043)
MVP		0.75
MPC		1.1
ClinPred		0.087	T
GERP RS		-0.84
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.2
Varity_R		0.32
gMVP		0.67
Mutation Taster		=88/12	polymorphism

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

Other links and lift over

dbSNP: rs752591958; hg19: chr17-29552144;