rs1554702106

chr9-95485757-G-Achr9-95485757-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM2 PP2 PP3

The NM_000264.5(PTCH1):c.512C>T(p.Thr171Ile) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic outcome for this variant. 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. T171A) 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: 9.60

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]

ACMG classification

Verdict is Uncertain_significance. Variant got 4 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, PTCH1
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.827

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PTCH1	NM_000264.5	c.512C>T	p.Thr171Ile	missense_variant	3/24	ENST00000331920.11
PTCH1	NM_001083603.3	c.509C>T	p.Thr170Ile	missense_variant	3/24	ENST00000437951.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PTCH1	ENST00000331920.11	c.512C>T	p.Thr171Ile	missense_variant	3/24	5	NM_000264.5	A2
PTCH1	ENST00000437951.6	c.509C>T	p.Thr170Ile	missense_variant	3/24	5	NM_001083603.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 31

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

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Oct 31, 2022

Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt PTCH1 protein function. 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: 524522). This variant has not been reported in the literature in individuals affected with PTCH1-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces threonine, which is neutral and polar, with isoleucine, which is neutral and non-polar, at codon 171 of the PTCH1 protein (p.Thr171Ile). -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 26, 2020

The p.T171I variant (also known as c.512C>T), located in coding exon 3 of the PTCH1 gene, results from a C to T substitution at nucleotide position 512. The threonine at codon 171 is replaced by isoleucine, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.77
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.41
Cadd	Uncertain	25
Dann	Uncertain	1.0
DEOGEN2	Pathogenic	0.83	D;.;.;.;.;.;.;.;.;.;.;.;.
Eigen	Pathogenic	0.79
Eigen_PC	Pathogenic	0.75
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.95	D;.;D;D;.;.;D;.;.;.;D;D;D
M_CAP	Uncertain	0.26	D
MetaRNN	Pathogenic	0.83	D;D;D;D;D;D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	0.85	D
MutationAssessor	Uncertain	2.7	M;.;.;.;.;.;.;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D;D
PrimateAI	Uncertain	0.78	T
PROVEAN	Uncertain	-3.9	D;D;D;D;D;D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.74
Sift	Benign	0.046	D;D;D;D;D;D;D;D;D;D;D;T;T
Sift4G	Uncertain	0.029	D;D;D;D;D;D;D;D;D;D;D;D;D
Polyphen		1.0	D;.;.;D;D;.;D;.;.;.;.;.;.
Vest4		0.98
MutPred		0.42		Loss of glycosylation at T171 (P = 0.0463);.;.;.;.;.;.;.;.;.;.;.;.;
MVP		0.83
MPC		1.5
ClinPred		0.98	D
GERP RS		5.9
Varity_R		0.42
gMVP		0.86

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

Publications

LitVar

Other links and lift over

dbSNP: rs1554702106; hg19: chr9-98248039;