chr10-87933168-GCA-TTT

Position:

• chr10-87933168-GCA-TTT

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PM1 PM2 PM5 PP2 PP3

The NM_000314.8(PTEN):​c.409_411delinsTTT​(p.Ala137Phe) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. 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. A137G) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 32)
• Consequence: PTEN NM_000314.8 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 9.53

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 Likely_pathogenic. Variant got 8 ACMG points.

• PM1: In a hotspot region, there are 10 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 14 uncertain in NM_000314.8
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr10-87933169-C-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 3340217.Status of the report is criteria_provided_single_submitter, 1 stars.
• PP2: Missense variant in gene, where missense usually causes diseases (based on misZ statistic), PTEN. . Gene score misZ 3.4883 (greater than the threshold 3.09). Trascript score misZ 4.1129 (greater than threshold 3.09). GenCC has associacion of gene with Lhermitte-Duclos disease, Bannayan-Riley-Ruvalcaba syndrome, Proteus syndrome, macrocephaly-autism syndrome, Cowden syndrome 1, Cowden disease, Proteus-like syndrome, leiomyosarcoma, activated PI3K-delta syndrome, PTEN hamartoma tumor syndrome, glioma susceptibility 2, renal cell carcinoma.
• PP3: No computational evidence supports a deleterious effect, but strongly conserved according to phyloP

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
PTEN	NM_000314.8	c.409_411delinsTTT	p.Ala137Phe	missense_variant	5/9	ENST00000371953.8
PTEN	NM_001304717.5	c.928_930delinsTTT	p.Ala310Phe	missense_variant	6/10
PTEN	NM_001304718.2	c.-342_-340delinsTTT		5_prime_UTR_variant	4/9

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
PTEN	ENST00000371953.8	c.409_411delinsTTT	p.Ala137Phe	missense_variant	5/9	1	NM_000314.8	P1

Frequencies

GnomAD3 genomes Cov.: 32

We have no GnomAD4 exomes data on this position. Probably position not covered by the project.

GnomAD4 genome Cov.: 32

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

PTEN hamartoma tumor syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Oct 20, 2019

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. 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 and their clinical significance is uncertain. This variant has not been reported in the literature in individuals with PTEN-related conditions. ClinVar contains an entry for this variant (Variation ID: 237645). This variant is not present in population databases (ExAC no frequency). This sequence change replaces alanine with phenylalanine at codon 137 of the PTEN protein (p.Ala137Phe). The alanine residue is highly conserved and there is a moderate physicochemical difference between alanine and phenylalanine. -

Computational scores

Source: dbNSFP v4.3

Splicing

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

Publications

LitVar

Other links and lift over

dbSNP: rs878853938; hg19: chr10-89692925;