chr17-31206240-T-C

Variant names:

• chr17-31206240-T-C
• rs878853864
• NM_001042492.3:c.1261T>C

Variant summary

Our verdict is Uncertain significance. The variant received 4 ACMG points: 4P and 0B. PM1 PM2

The NM_001042492.3(NF1):​c.1261T>C​(p.Ser421Pro) variant causes a missense, splice region change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,376 control chromosomes in the GnomAD database, with no homozygous occurrence. 3/3 splice prediction tools predict no significant impact on normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. S421A) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: NF1 NM_001042492.3 missense, splice_region
• Scores: Splicing: ADA: 0.001304
• Clinical Significance: Not reported in ClinVar
• 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: ClinGen, Labcorp Genetics (formerly Invitae), G2P, Genomics England PanelApp
• neurofibromatosis-Noonan syndrome

  Inheritance: AD Classification: STRONG, SUPPORTIVE Submitted by: Orphanet, Genomics England PanelApp
• 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: Unknown Classification: NO_KNOWN Submitted by: ClinGen

ACMG classification

Our verdict: Uncertain_significance. The variant received 4 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 28 uncertain in NM_001042492.3
• PM2: Very rare variant in population databases, with high coverage

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001042492.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NF1	NM_001042492.3	MANE Select	c.1261T>C	p.Ser421Pro	missense splice_region	Exon 12 of 58	NP_001035957.1	P21359-1
	NF1	NM_000267.4		c.1261T>C	p.Ser421Pro	missense splice_region	Exon 12 of 57	NP_000258.1
	NF1	NM_001128147.3		c.1261T>C	p.Ser421Pro	missense splice_region	Exon 12 of 15	NP_001121619.1	P21359-5

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	NF1	ENST00000358273.9	TSL:1 MANE Select	c.1261T>C	p.Ser421Pro	missense splice_region	Exon 12 of 58	ENSP00000351015.4	P21359-1
	NF1	ENST00000356175.7	TSL:1	c.1261T>C	p.Ser421Pro	missense splice_region	Exon 12 of 57	ENSP00000348498.3	P21359-2
	NF1	ENST00000431387.8	TSL:1	c.1261T>C	p.Ser421Pro	missense splice_region	Exon 12 of 15	ENSP00000412921.4	P21359-5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461376 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 727012

African (AFR) AF: 0.00 AC: 0 AN: 33450

American (AMR) AF: 0.00 AC: 0 AN: 44720

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26114

East Asian (EAS) AF: 0.00 AC: 0 AN: 39684

South Asian (SAS) AF: 0.00 AC: 0 AN: 86248

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53412

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5760

European-Non Finnish (NFE) AF: 9.00e-7 AC: 1 AN: 1111636

Other (OTH) AF: 0.00 AC: 0 AN: 60352

GnomAD4 genome Cov.: 32

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Uncertain	0.36
BayesDel_addAF	Uncertain	0.067	T
BayesDel_noAF	Benign	-0.14
CADD	Benign	22
DANN	Benign	0.56
DEOGEN2	Uncertain	0.48	T
Eigen	Uncertain	0.32
Eigen_PC	Uncertain	0.41
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.92	D
M_CAP	Pathogenic	0.56	D
MetaRNN	Uncertain	0.72	D
MetaSVM	Benign	-0.59	T
MutationAssessor	Benign	0.86	L
PhyloP100		7.6
PrimateAI	Pathogenic	0.83	D
PROVEAN	Benign	-0.79	N
REVEL	Benign	0.20
Sift	Benign	0.50	T
Sift4G	Benign	0.64	T
Polyphen		0.99	D
Vest4		0.81
MutPred		0.61		Loss of helix (P = 0.0076)
MVP		0.66
MPC		1.9
ClinPred		0.68	D
GERP RS		6.2
Varity_R		0.38
gMVP		0.85
Mutation Taster		=26/74	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.0013
dbscSNV1_RF	Benign	0.046
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: rs878853864; hg19: chr17-29533258;