chr17-31181760-C-A

Variant names:

• chr17-31181760-C-A
• rs769048538
• NM_001042492.3:c.705C>A

Variant summary

Our verdict is Pathogenic. The variant received 12 ACMG points: 12P and 0B. PVS1 PM2 PP5_Moderate

The NM_001042492.3(NF1):​c.705C>A​(p.Tyr235*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000686 in 1,456,864 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★). Synonymous variant affecting the same amino acid position (i.e. Y235Y) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: NF1 NM_001042492.3 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 2.21
• Publications: 5 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: Pathogenic. The variant received 12 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 17-31181760-C-A is Pathogenic according to our data. Variant chr17-31181760-C-A is described in ClinVar as Pathogenic. ClinVar VariationId is 956712.Status of the report is criteria_provided_single_submitter, 1 stars.

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.705C>A	p.Tyr235*	stop_gained	Exon 7 of 58	NP_001035957.1	P21359-1
	NF1	NM_000267.4		c.705C>A	p.Tyr235*	stop_gained	Exon 7 of 57	NP_000258.1
	NF1	NM_001128147.3		c.705C>A	p.Tyr235*	stop_gained	Exon 7 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.705C>A	p.Tyr235*	stop_gained	Exon 7 of 58	ENSP00000351015.4	P21359-1
	NF1	ENST00000356175.7	TSL:1	c.705C>A	p.Tyr235*	stop_gained	Exon 7 of 57	ENSP00000348498.3	P21359-2
	NF1	ENST00000431387.8	TSL:1	c.705C>A	p.Tyr235*	stop_gained	Exon 7 of 15	ENSP00000412921.4	P21359-5

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.86e-7 AC: 1 AN: 1456864 Hom.: 0 Cov.: 33 AF XY: 0.00000138 AC XY: 1 AN XY: 725082

⚠️ 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: 33424

American (AMR) AF: 0.00 AC: 0 AN: 44712

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26072

East Asian (EAS) AF: 0.00 AC: 0 AN: 39578

South Asian (SAS) AF: 0.00 AC: 0 AN: 86092

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 53406

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5696

European-Non Finnish (NFE) AF: 9.03e-7 AC: 1 AN: 1107668

Other (OTH) AF: 0.00 AC: 0 AN: 60216

⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

GnomAD4 genome Cov.: 32

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
1	-	-	Neurofibromatosis, type 1 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.61	D
BayesDel_noAF	Pathogenic	0.63
CADD	Pathogenic	36
DANN	Uncertain	1.0
Eigen	Pathogenic	0.83
Eigen_PC	Pathogenic	0.73
FATHMM_MKL	Uncertain	0.92	D
PhyloP100		2.2
Vest4		0.95
GERP RS		5.9
PromoterAI		-0.013	Neutral
Mutation Taster		=0/200	disease causing (ClinVar)

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: rs769048538; hg19: chr17-29508778;