rs863224652

Positions:

• chr9-95458248-A-G

Variant summary

Our verdict is Likely pathogenic. Variant got 7 ACMG points: 7P and 0B. PM1 PM2 PP2 PP3_Moderate

The NM_000264.5(PTCH1):​c.2933T>C​(p.Leu978Pro) 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. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: PTCH1 NM_000264.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 8.65

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.

• PM1: In a topological_domain Extracellular (size 257) in uniprot entity PTC1_HUMAN there are 24 pathogenic changes around while only 5 benign (83%) in NM_000264.5
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), PTCH1. . Gene score misZ 1.6774 (greater than the threshold 3.09). Trascript score misZ 3.1343 (greater than threshold 3.09). GenCC has associacion of gene with holoprosencephaly 7, nevoid basal cell carcinoma syndrome, holoprosencephaly.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.926

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PTCH1	NM_000264.5	c.2933T>C	p.Leu978Pro	missense_variant	18/24	ENST00000331920.11	NP_000255.2
PTCH1	NM_001083603.3	c.2930T>C	p.Leu977Pro	missense_variant	18/24	ENST00000437951.6	NP_001077072.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PTCH1	ENST00000331920.11	c.2933T>C	p.Leu978Pro	missense_variant	18/24	5	NM_000264.5	ENSP00000332353	A2
PTCH1	ENST00000437951.6	c.2930T>C	p.Leu977Pro	missense_variant	18/24	5	NM_001083603.3	ENSP00000389744

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 33

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

Labcorp Genetics (formerly Invitae), Labcorp

Mar 15, 2015

This variant has not been published in the literature and is not present in population databases. Algorithms developed to predict the effect of missense changes on protein structure and function (SIFT, PolyPhen-2, Align-GVGD) all suggest that this variant is likely to be disruptive, but these predictions have not been confirmed by published functional studies. In summary, this is a novel missense change with uncertain impact on protein function. It has been classified as a Variant of Uncertain Significance. This sequence change replaces leucine with proline at codon 978 of the PTCH1 protein (p.Leu978Pro). The leucine residue is highly conserved and there is a moderate physicochemical difference between leucine and proline. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Oct 20, 2020

The p.L978P variant (also known as c.2933T>C), located in coding exon 18 of the PTCH1 gene, results from a T to C substitution at nucleotide position 2933. The leucine at codon 978 is replaced by proline, 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	1.0
BayesDel_addAF	Pathogenic	0.45	D
BayesDel_noAF	Pathogenic	0.41
CADD	Pathogenic	28
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.86	D;.;.;.;.;.;.
Eigen	Pathogenic	0.81
Eigen_PC	Pathogenic	0.76
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.92	D;.;D;D;.;.;D
M_CAP	Pathogenic	0.31	D
MetaRNN	Pathogenic	0.93	D;D;D;D;D;D;D
MetaSVM	Uncertain	0.65	D
MutationAssessor	Uncertain	2.6	M;.;.;.;.;.;.
MutationTaster	Benign	1.0	D;D;D;D;D;D;D
PrimateAI	Pathogenic	0.88	D
PROVEAN	Pathogenic	-5.4	D;D;D;D;D;D;D
REVEL	Pathogenic	0.90
Sift	Uncertain	0.0010	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
Vest4		0.98
MutPred		0.76		Loss of sheet (P = 0.0315);.;.;.;.;.;.;
MVP		0.95
MPC		1.9
ClinPred		1.0	D
GERP RS		5.1
Varity_R		0.97
gMVP		0.99

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: rs863224652; hg19: chr9-98220530;