NM_000264.5:c.886delT

Variant names:

• chr9-95480448-CA-C
• rs1131690987
• NM_000264.5:c.886delT

Variant summary

Our verdict is Pathogenic. The variant received 18 ACMG points: 18P and 0B. PVS1 PM2 PP5_Very_Strong

The NM_000264.5(PTCH1):​c.886delT​(p.Cys296AlafsTer28) variant causes a frameshift change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★★). Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 31)
• Consequence: PTCH1 NM_000264.5 frameshift
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:2
• Conservation: PhyloP100: 8.95
• Publications: 2 publications found

Genes affected

PTCH1 (HGNC:9585): (patched 1) This gene encodes a member of the patched family of proteins and a component of the hedgehog signaling pathway. Hedgehog signaling is important in embryonic development and tumorigenesis. The encoded protein is the receptor for the secreted hedgehog ligands, which include sonic hedgehog, indian hedgehog and desert hedgehog. Following binding by one of the hedgehog ligands, the encoded protein is trafficked away from the primary cilium, relieving inhibition of the G-protein-coupled receptor smoothened, which results in activation of downstream signaling. Mutations of this gene have been associated with basal cell nevus syndrome and holoprosencephaly. [provided by RefSeq, Aug 2017]

PTCH1 Gene-Disease associations (from GenCC):

• basal cell nevus syndrome 1

  Inheritance: AD Classification: DEFINITIVE Submitted by: G2P
• holoprosencephaly 7

  Inheritance: AD Classification: DEFINITIVE, LIMITED Submitted by: Ambry Genetics, Labcorp Genetics (formerly Invitae), G2P
• nevoid basal cell carcinoma syndrome

  Inheritance: AD Classification: DEFINITIVE, STRONG, SUPPORTIVE Submitted by: Genomics England PanelApp, ClinGen, Labcorp Genetics (formerly Invitae), Orphanet
• holoprosencephaly

  Inheritance: AD Classification: LIMITED Submitted by: Illumina

ACMG classification

Our verdict: Pathogenic. The variant received 18 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 9-95480448-CA-C is Pathogenic according to our data. Variant chr9-95480448-CA-C is described in ClinVar as Pathogenic. ClinVar VariationId is 428840.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PTCH1	NM_000264.5	c.886delT	p.Cys296AlafsTer28	frameshift_variant	Exon 6 of 24	ENST00000331920.11	NP_000255.2
PTCH1	NM_001083603.3	c.883delT	p.Cys295AlafsTer28	frameshift_variant	Exon 6 of 24	ENST00000437951.6	NP_001077072.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PTCH1	ENST00000331920.11	c.886delT	p.Cys296AlafsTer28	frameshift_variant	Exon 6 of 24	5	NM_000264.5	ENSP00000332353.6
PTCH1	ENST00000437951.6	c.883delT	p.Cys295AlafsTer28	frameshift_variant	Exon 6 of 24	5	NM_001083603.3	ENSP00000389744.2

Frequencies

GnomAD3 genomes Cov.: 31

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 31

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Gorlin syndrome Pathogenic:1

Jan 14, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change creates a premature translational stop signal (p.Cys296Alafs*28) in the PTCH1 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in PTCH1 are known to be pathogenic (PMID: 16301862, 16419085). This variant is not present in population databases (gnomAD no frequency). This premature translational stop signal has been observed in individual(s) with basal cell nevus syndrome (PMID: 9620294). ClinVar contains an entry for this variant (Variation ID: 428840). For these reasons, this variant has been classified as Pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Nov 30, 2015

Ambry Genetics

Significance: Pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.886delT pathogenic mutation, located in coding exon 6 of the PTCH1 gene, results from a deletion of one nucleotide at position 886, causing a translational frameshift with a predicted alternate stop codon. This mutation (designated as T886 del) has been previously identified in a nevoid basal cell-carcinoma syndrome kindred (Aszterbaum M et al, J. Invest. Dermatol. 1998 Jun; 110(6):885-8). In addition to this published clinical data, since frameshifts are typically deleterious in nature, this alteration is interpreted as a disease-causing mutation (ACMG Recommendations for Standards for Interpretation and Reporting of Sequence Variations. Revision 2007. Genet Med. 2008;10:294). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		8.9
Mutation Taster		=0/200	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs1131690987; hg19: chr9-98242730;