10-87894110-G-T

Variant summary

Our verdict is Pathogenic. Variant got 22 ACMG points: 22P and 0B. PVS1 PM2 PP3_Strong PP5_Very_Strong

The NM_000314.8(PTEN):c.164+1G>T variant causes a splice donor 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. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Pathogenic (★★).

• Frequency: Genomes: not found (cov: 32)
• Consequence: PTEN NM_000314.8 splice_donor
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Pathogenic criteria provided, multiple submitters, no conflicts P:4
• Conservation: PhyloP100: 9.42

Genes affected

PTEN (HGNC:9588): (phosphatase and tensin homolog) This gene was identified as a tumor suppressor that is mutated in a large number of cancers at high frequency. The protein encoded by this gene is a phosphatidylinositol-3,4,5-trisphosphate 3-phosphatase. It contains a tensin like domain as well as a catalytic domain similar to that of the dual specificity protein tyrosine phosphatases. Unlike most of the protein tyrosine phosphatases, this protein preferentially dephosphorylates phosphoinositide substrates. It negatively regulates intracellular levels of phosphatidylinositol-3,4,5-trisphosphate in cells and functions as a tumor suppressor by negatively regulating AKT/PKB signaling pathway. The use of a non-canonical (CUG) upstream initiation site produces a longer isoform that initiates translation with a leucine, and is thought to be preferentially associated with the mitochondrial inner membrane. This longer isoform may help regulate energy metabolism in the mitochondria. A pseudogene of this gene is found on chromosome 9. Alternative splicing and the use of multiple translation start codons results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Feb 2015]

ACMG classification

Verdict is Pathogenic. Variant got 22 ACMG points.

• PVS1: Splicing variant, LoF is a know mechanism of disease, Cryptic splice site detected, with MaxEntScore 8, offset of -5, new splice context is: gtaGTaagt. Cryptic site results in frameshift change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP3: Splicing scoreres supports a deletorius effect: Scorers claiming Pathogenic: dbscSNV1_ADA, dbscSNV1_RF, max_spliceai. No scorers claiming Uncertain. No scorers claiming Benign.
• PP5: Variant 10-87894110-G-T is Pathogenic according to our data. Variant chr10-87894110-G-T is described in ClinVar as [Pathogenic]. Clinvar id is 381529.Status of the report is criteria_provided_multiple_submitters_no_conflicts, 2 stars. Variant chr10-87894110-G-T is described in Lovd as [Pathogenic].

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PTEN	NM_000314.8	c.164+1G>T		splice_donor_variant		ENST00000371953.8
PTEN	NM_001304717.5	c.683+1G>T		splice_donor_variant
PTEN	NM_001304718.2	c.-541+1G>T		splice_donor_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PTEN	ENST00000371953.8	c.164+1G>T		splice_donor_variant		1	NM_000314.8	P1

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome Cov.: 27

GnomAD4 genome Cov.: 32

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:4

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

Cowden syndrome 1 Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Myriad Genetics, Inc.

Sep 26, 2023

This variant is considered pathogenic. This variant occurs within a consensus splice junction and is predicted to result in abnormal mRNA splicing of either an out-of-frame exon or an in-frame exon necessary for protein stability and/or normal function. This variant has been reported in multiple individuals with clinical features of gene-specific disease [PMID: 22381246, 24778394, 17526800, 11886535]. -

PTEN hamartoma tumor syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Invitae

Nov 22, 2022

For these reasons, this variant has been classified as Pathogenic. Studies have shown that disruption of this splice site is associated with altered splicing resulting in multiple RNA products (PMID: 11886535). ClinVar contains an entry for this variant (Variation ID: 381529). Disruption of this splice site has been observed in individuals with clinical features of PTEN-related conditions (PMID: 11886535, 23335809; Invitae). This variant is not present in population databases (gnomAD no frequency). This sequence change affects a donor splice site in intron 2 of the PTEN gene. It is expected to disrupt RNA splicing. Variants that disrupt the donor or acceptor splice site typically lead to a loss of protein function (PMID: 16199547), and loss-of-function variants in PTEN are known to be pathogenic (PMID: 9467011, 21194675). -

not provided Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

GeneDx

Jan 09, 2017

The c.164+1G>T splice site variant in the PTEN gene has been previously reported in at least one individual with PTEN-hamartoma tumor syndrome (Mester et al., 2012; Ngeow et al., 2014; Nizialek et al., 2015). This variant destroys the canonical splice donor site in intron 2, and is expected to cause abnormal gene splicing. Based on currently available evidence, we consider c.164+1G>T to be pathogenic. -

Hereditary cancer-predisposing syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Ambry Genetics

Mar 11, 2024

The c.164+1G>T intronic pathogenic mutation results from a G to T substitution one nucleotide after coding exon 2 of the PTEN gene. This mutation has been reported in an individual meeting at least relaxed International Cowden Consortium operational diagnostic criteria for Cowden syndrome, with clinical features including renal and colorectal cancer (Ngeow J et al. J. Clin. Oncol. 2014 Jun; 32(17):1818-24). In addition, another mutation at this same position (c.164+1G>A), has been reported in an individual with classic Cowden disease. The authors noted that the c.164+1G>A mutation activates a cryptic splice site resulting in a complex rearrangement, including partial retention of exon 1 and skipping of exon 2 (Trojan J et al. J. Invest. Dermatol. 2001 Dec; 117(6):1650-3). This nucleotide position is highly conserved in available vertebrate species. In silico splice site analysis predicts that this alteration will weaken the native splice donor site. In addition to the clinical data presented in the literature, alterations that disrupt the canonical splice site are expected to cause aberrant splicing, resulting in an abnormal protein or a transcript that is subject to nonsense-mediated mRNA decay. As such, this alteration is classified as a disease-causing mutation. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.41	D
BayesDel_noAF	Pathogenic	0.35
Cadd	Pathogenic	34
Dann	Uncertain	1.0
Eigen	Pathogenic	1.2
Eigen_PC	Pathogenic	1.1
FATHMM_MKL	Pathogenic	0.98	D
MutationTaster	Benign	1.0	D
GERP RS		5.2

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.94
SpliceAI score (max)		0.71		Details are displayed if max score is > 0.2
DS_DL_spliceai		0.71		Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs1554893835; hg19: chr10-89653867; COSMIC: COSV64308544;