chr9-95449930-C-T

Position:

• chr9-95449930-C-T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP2

The NM_000264.5(PTCH1):​c.3460G>A​(p.Ala1154Thr) variant causes a missense change involving the alteration of a conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,461,764 control chromosomes in the GnomAD database, with no homozygous occurrence. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: PTCH1 NM_000264.5 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 7.86

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 (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• 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.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
PTCH1	NM_000264.5	c.3460G>A	p.Ala1154Thr	missense_variant	21/24	ENST00000331920.11	NP_000255.2
PTCH1	NM_001083603.3	c.3457G>A	p.Ala1153Thr	missense_variant	21/24	ENST00000437951.6	NP_001077072.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
PTCH1	ENST00000331920.11	c.3460G>A	p.Ala1154Thr	missense_variant	21/24	5	NM_000264.5	ENSP00000332353.6
PTCH1	ENST00000437951.6	c.3457G>A	p.Ala1153Thr	missense_variant	21/24	5	NM_001083603.3	ENSP00000389744.2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.00000398 AC: 1 AN: 251354 Hom.: 0 AF XY: 0.00000736 AC XY: 1 AN XY: 135876

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 SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00000880

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1461764 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727184

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: 0.0000166

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

Oct 25, 2016

In summary, this variant is a novel missense change that is not predicted to affect protein function. There is no indication that it causes disease, but the available evidence is currently insufficient to prove that conclusively. Therefore, it has been classified as a Variant of Uncertain Significance. 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 tolerated, but these predictions have not been confirmed by published functional studies. This variant is not present in population databases (ExAC no frequency) and has not been reported in the literature in individuals with a PTCH1-related disease. This sequence change replaces alanine with threonine at codon 1154 of the PTCH1 protein (p.Ala1154Thr). The alanine residue is moderately conserved and there is a small physicochemical difference between alanine and threonine. -

Hereditary cancer-predisposing syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Apr 20, 2024

The p.A1154T variant (also known as c.3460G>A), located in coding exon 21 of the PTCH1 gene, results from a G to A substitution at nucleotide position 3460. The alanine at codon 1154 is replaced by threonine, an amino acid with similar properties. This amino acid position is conserved. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on the available evidence, the clinical significance of this variant remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.17
BayesDel_addAF	Pathogenic	0.32	D
BayesDel_noAF	Pathogenic	0.23
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Benign	0.33	T;.;.;.;.;.;.
Eigen	Uncertain	0.40
Eigen_PC	Uncertain	0.50
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Uncertain	0.89	D;.;D;D;.;.;D
M_CAP	Benign	0.073	D
MetaRNN	Uncertain	0.62	D;D;D;D;D;D;D
MetaSVM	Uncertain	0.15	D
MutationAssessor	Benign	1.0	L;.;.;.;.;.;.
PrimateAI	Pathogenic	0.81	D
PROVEAN	Benign	-0.87	N;N;N;N;N;N;N
REVEL	Pathogenic	0.69
Sift	Benign	0.39	T;T;T;T;T;T;T
Sift4G	Benign	0.39	T;T;T;T;T;T;T
Polyphen		0.60	P;.;.;B;B;.;D
Vest4		0.70
MutPred		0.64		Loss of catalytic residue at A1154 (P = 0.0743);.;.;.;.;.;.;
MVP		0.70
MPC		0.58
ClinPred		0.52	D
GERP RS		5.5
Varity_R		0.53
gMVP		0.74

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.060		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: rs878853857; hg19: chr9-98212212;