Genetic Variant PTCH1:p.Ile921Val (chr9-95459726-T-C) – ACMG Classification: Likely_benign (-4 pts)

Variant summary

Our verdict is Likely benign. The variant received -4 ACMG points: 2P and 6B. PM1BP4BP6BS2

The NM_000264.5(PTCH1):c.2761A>G(p.Ile921Val) variant causes a missense change. The variant allele was found at a frequency of 0.0000235 in 1,614,088 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. I921M) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.000020 ( 0 hom., cov: 33)

Exomes 𝑓: 0.000024 ( 0 hom. )

Consequence

PTCH1
NM_000264.5 missense

Scores

Clinical Significance

Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:3B:1

Conservation

PhyloP100: 5.79

Publications

1 publications found

Variant links:

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

PTCH1 links:

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -4 ACMG points.

PM1

In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 3 benign, 16 uncertain in NM_000264.5

BP4

Computational evidence support a benign effect (MetaRNN=0.3195328).

BP6

Variant 9-95459726-T-C is Benign according to our data. Variant chr9-95459726-T-C is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 409128.

BS2

High AC in GnomAdExome4 at 35 AD gene.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_000264.5. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
PTCH1	NM_000264.5	MANE Select	c.2761A>G	p.Ile921Val	missense	Exon 17 of 24	NP_000255.2
PTCH1	NM_001083603.3	MANE Plus Clinical	c.2758A>G	p.Ile920Val	missense	Exon 17 of 24	NP_001077072.1
PTCH1	NM_001354918.2		c.2605A>G	p.Ile869Val	missense	Exon 16 of 23	NP_001341847.1

Ensembl Transcripts

Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein
PTCH1	ENST00000331920.11	TSL:5 MANE Select	c.2761A>G	p.Ile921Val	missense	Exon 17 of 24	ENSP00000332353.6
PTCH1	ENST00000437951.6	TSL:5 MANE Plus Clinical	c.2758A>G	p.Ile920Val	missense	Exon 17 of 24	ENSP00000389744.2
PTCH1	ENST00000429896.6	TSL:1	c.2308A>G	p.Ile770Val	missense	Exon 17 of 24	ENSP00000414823.2

Frequencies

GnomAD3 genomes

AF:

0.0000197

AC:

AN:

152200

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.0000294

Gnomad OTH

AF:

0.00

GnomAD2 exomes

AF:

0.0000159

AC:

AN:

251474

AF XY:

0.0000294

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.0000264

Gnomad OTH exome

AF:

0.000163

GnomAD4 exome

AF:

0.0000239

AC:

AN:

1461888

Hom.:

Cov.:

AF XY:

0.0000261

AC XY:

AN XY:

727244

show subpopulations

African (AFR)

AF:

0.00

AC:

AN:

33480

American (AMR)

AF:

0.00

AC:

AN:

44724

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

26136

East Asian (EAS)

AF:

0.00

AC:

AN:

39700

South Asian (SAS)

AF:

0.00

AC:

AN:

86256

European-Finnish (FIN)

AF:

0.00

AC:

AN:

53418

Middle Eastern (MID)

AF:

0.00

AC:

AN:

5766

European-Non Finnish (NFE)

AF:

0.0000297

AC:

AN:

1112012

Other (OTH)

AF:

0.0000331

AC:

AN:

60396

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.486

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Exome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

GnomAD4 genome

AF:

0.0000197

AC:

AN:

152200

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74352

show subpopulations

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR)

AF:

0.0000241

AC:

AN:

41446

American (AMR)

AF:

0.00

AC:

AN:

15282

Ashkenazi Jewish (ASJ)

AF:

0.00

AC:

AN:

3468

East Asian (EAS)

AF:

0.00

AC:

AN:

5204

South Asian (SAS)

AF:

0.00

AC:

AN:

4828

European-Finnish (FIN)

AF:

0.00

AC:

AN:

10616

Middle Eastern (MID)

AF:

0.00

AC:

AN:

316

European-Non Finnish (NFE)

AF:

0.0000294

AC:

AN:

68040

Other (OTH)

AF:

0.00

AC:

AN:

2088

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000102688), which strongly suggests a high chance of mosaicism in these individuals.

Allele Balance Distribution

Red line indicates average allele balance

Average allele balance: 0.325

Heterozygous variant carriers

0.00

0.20

0.40

0.60

0.80

0.95

Allele balance

Age Distribution

Genome Het

Variant carriers

<30

30-35

35-40

40-45

45-50

50-55

55-60

60-65

65-70

70-75

75-80

>80

Age

Alfa

AF:

0.0000282

Hom.:

Bravo

AF:

0.0000302

ExAC

AF:

0.0000165

AC:

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:3Benign:1

Revision: criteria provided, conflicting classifications

LINK: link

Submissions by phenotype

not provided

Uncertain:2

Feb 23, 2025

GeneDx

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis indicates that this missense variant does not alter protein structure/function; Reported as a germline variant in an individual with myeloid malignancy (PMID: 31911633); This variant is associated with the following publications: (PMID: 8906794, 31911633)

Jan 17, 2023

Quest Diagnostics Nichols Institute San Juan Capistrano

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The frequency of this variant in the general population, 0.000031 (4/129188 chromosomes, http://gnomad.broadinstitute.org), is uninformative in assessment of its pathogenicity. In the published literature, the variant has been reported in in a cohort of 690 individuals with different myeloid malignancies (PMID:31911633(2020)), however limited clinical significance was provided. Analysis of this variant using bioinformatics tools for the prediction of the effect of amino acid changes on protein structure and function yielded predictions that this variant is benign. Based on the available information, we are unable to determine the clinical significance of this variant.

Hereditary cancer-predisposing syndrome

Uncertain:1

Jul 09, 2024

Ambry Genetics

Significance:Uncertain significance

Review Status:criteria provided, single submitter

Collection Method:clinical testing

The p.I921V variant (also known as c.2761A>G), located in coding exon 17 of the PTCH1 gene, results from an A to G substitution at nucleotide position 2761. The isoleucine at codon 921 is replaced by valine, an amino acid with highly similar properties. This amino acid position is well conserved in available vertebrate species. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear.

Gorlin syndrome

Benign:1

Jan 23, 2025

Labcorp Genetics (formerly Invitae), Labcorp

Significance:Likely benign

Review Status:criteria provided, single submitter

Collection Method:clinical testing

Computational scores

Source: dbNSFP v4.9

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.10

BayesDel_addAF

Uncertain

0.039

BayesDel_noAF

Uncertain

-0.070

CADD

Benign

(source)

DANN

Benign

0.71

DEOGEN2

Benign

0.26

Eigen

Benign

0.061

Eigen_PC

Benign

0.20

FATHMM_MKL

Uncertain

0.96

LIST_S2

Benign

0.65

M_CAP

Benign

0.011

MetaRNN

Benign

0.32

MetaSVM

Uncertain

0.086

MutationAssessor

Benign

1.8

PhyloP100

5.8

PrimateAI

Uncertain

0.70

PROVEAN

Benign

-0.28

REVEL

Uncertain

0.53

Sift

Benign

0.96

Sift4G

Benign

1.0

Polyphen

0.21

Vest4

0.46

MutPred

0.56

Gain of helix (P = 0.0325)

MVP

0.57

MPC

0.58

ClinPred

0.11

GERP RS

5.0

Varity_R

0.069

gMVP

0.47

Mutation Taster

=37/63

disease causing

(source)

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

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Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

Publications

ACMG classification

Variant Effect in Transcripts

RefSeq Transcripts

Ensembl Transcripts

Frequencies

Age Distribution

Age Distribution

ClinVar

Submissions by phenotype

Computational scores

Splicing

Publications

Other links and lift over