rs1554698275

Variant names:

• chr9-95476805-GC-TA
• rs1554698275
• NM_000264.5:c.1555_1556delGCinsTA

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 1P and 0B. PP3

The NM_000264.5(PTCH1):​c.1555_1556delGCinsTA​(p.Ala519Tyr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. It is difficult to determine the true allele frequency of this variant because it is of type MNV, and the frequency of such variant types in population databases may be underestimated and unreliable. Variant has been reported in ClinVar as Uncertain significance (★★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A519D) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PTCH1 NM_000264.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 9.37
• Publications: 0 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: Uncertain_significance. The variant received 1 ACMG points.

• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
PTCH1	NM_000264.5	c.1555_1556delGCinsTA	p.Ala519Tyr	missense_variant		ENST00000331920.11	NP_000255.2
PTCH1	NM_001083603.3	c.1552_1553delGCinsTA	p.Ala518Tyr	missense_variant		ENST00000437951.6	NP_001077072.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
PTCH1	ENST00000331920.11	c.1555_1556delGCinsTA	p.Ala519Tyr	missense_variant		5	NM_000264.5	ENSP00000332353.6
PTCH1	ENST00000437951.6	c.1552_1553delGCinsTA	p.Ala518Tyr	missense_variant		5	NM_001083603.3	ENSP00000389744.2

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Gorlin syndrome Uncertain:1

Aug 09, 2023

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with tyrosine, which is neutral and polar, at codon 519 of the PTCH1 protein (p.Ala519Tyr). An algorithm developed to predict the effect of missense changes on protein structure and function (PolyPhen-2) suggests that this variant is likely to be disruptive. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. ClinVar contains an entry for this variant (Variation ID: 524526). This variant has not been reported in the literature in individuals affected with PTCH1-related conditions. Information on the frequency of this variant in the gnomAD database is not available, as this variant may be reported differently in the database. -

Hereditary cancer-predisposing syndrome Uncertain:1

May 15, 2025

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The c.1555_1556delGCinsTA variant (also known as p.A519Y), located in coding exon 11 of the PTCH1 gene, results from an in-frame deletion of GC and insertion of TA at nucleotide positions 1555 to 1556. This results in the substitution of the alanine residue for a tyrosine residue at codon 519, an amino acid with dissimilar properties. This amino acid position is highly conserved in available vertebrate species. In addition, the in silico prediction for this variant is inconclusive (Choi Y et al. PLoS ONE. 2012; 7(10):e46688). Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
PhyloP100		9.4

Splicing

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs1554698275; hg19: chr9-98239087;