rs863224649

chr9-95476110-G-Achr9-95476110-G-C

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM2 PP2 PP3_Strong

The NM_000264.5(PTCH1):c.1652C>T(p.Thr551Met) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,480 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. 13/20 in silico tools predict a damaging 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. T551K) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• 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 Likely_pathogenic. Variant got 7 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, 0.966

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PTCH1	NM_000264.5	c.1652C>T	p.Thr551Met	missense_variant	12/24	ENST00000331920.11
PTCH1	NM_001083603.3	c.1649C>T	p.Thr550Met	missense_variant	12/24	ENST00000437951.6

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PTCH1	ENST00000331920.11	c.1652C>T	p.Thr551Met	missense_variant	12/24	5	NM_000264.5	A2
PTCH1	ENST00000437951.6	c.1649C>T	p.Thr550Met	missense_variant	12/24	5	NM_001083603.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461480 Hom.: 0 Cov.: 34 AF XY: 0.00000138 AC XY: 1 AN XY: 727006

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

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

Aug 25, 2023

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. 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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on PTCH1 protein function. ClinVar contains an entry for this variant (Variation ID: 216373). 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 methionine, which is neutral and non-polar, at codon 551 of the PTCH1 protein (p.Thr551Met). -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

May 25, 2023

The p.T551M variant (also known as c.1652C>T), located in coding exon 12 of the PTCH1 gene, results from a C to T substitution at nucleotide position 1652. The threonine at codon 551 is replaced by methionine, 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	0.84
BayesDel_addAF	Pathogenic	0.53	D
BayesDel_noAF	Pathogenic	0.53
Cadd	Pathogenic	33
Dann	Pathogenic	1.0
DEOGEN2	Pathogenic	0.95	D;.;.;.;.;.;.;.
Eigen	Pathogenic	1.0
Eigen_PC	Pathogenic	0.96
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.96	D;.;D;D;.;.;D;D
M_CAP	Pathogenic	0.47	D
MetaRNN	Pathogenic	0.97	D;D;D;D;D;D;D;D
MetaSVM	Pathogenic	1.0	D
MutationAssessor	Pathogenic	3.3	M;.;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D
PrimateAI	Pathogenic	0.87	D
PROVEAN	Pathogenic	-4.5	D;D;D;D;D;D;D;D
REVEL	Pathogenic	0.94
Sift	Uncertain	0.0010	D;D;D;D;D;D;D;D
Sift4G	Pathogenic	0.0010	D;D;D;D;D;D;D;.
Polyphen		1.0	D;D;D;D;D;D;D;.
Vest4		0.94
MutPred		0.86		Loss of helix (P = 0.2271);.;.;.;.;.;.;.;
MVP		0.93
MPC		1.5
ClinPred		1.0	D
GERP RS		5.6
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.63
gMVP		0.94

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: rs863224649; hg19: chr9-98238392;