rs755822641

Positions:

• chr5-1272214-G-A
• chr5-1272214-G-C

Variant summary

Our verdict is Likely benign. Variant got -3 ACMG points: 2P and 5B. PM2 BP4_Strong BP6

The NM_198253.3(TERT):​c.2353C>T​(p.Pro785Ser) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000205 in 1,460,468 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/21 in silico tools predict 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. P785A) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000021 (0 hom.)
• Consequence: TERT NM_198253.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 0.263

Genes affected

TERT (HGNC:11730): (telomerase reverse transcriptase) Telomerase is a ribonucleoprotein polymerase that maintains telomere ends by addition of the telomere repeat TTAGGG. The enzyme consists of a protein component with reverse transcriptase activity, encoded by this gene, and an RNA component which serves as a template for the telomere repeat. Telomerase expression plays a role in cellular senescence, as it is normally repressed in postnatal somatic cells resulting in progressive shortening of telomeres. Deregulation of telomerase expression in somatic cells may be involved in oncogenesis. Studies in mouse suggest that telomerase also participates in chromosomal repair, since de novo synthesis of telomere repeats may occur at double-stranded breaks. Alternatively spliced variants encoding different isoforms of telomerase reverse transcriptase have been identified; the full-length sequence of some variants has not been determined. Alternative splicing at this locus is thought to be one mechanism of regulation of telomerase activity. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Likely_benign. Variant got -3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.048340857).
• BP6: Variant 5-1272214-G-A is Benign according to our data. Variant chr5-1272214-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 1508926.We mark this variant Likely_benign, oryginal submissions are: {Likely_benign=1, Uncertain_significance=1}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TERT	NM_198253.3	c.2353C>T	p.Pro785Ser	missense_variant	7/16	ENST00000310581.10
TERT	NM_001193376.3	c.2353C>T	p.Pro785Ser	missense_variant	7/15
TERT	NR_149162.3	n.2366-3581C>T		intron_variant, non_coding_transcript_variant
TERT	NR_149163.3	n.2330-3581C>T		intron_variant, non_coding_transcript_variant

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TERT	ENST00000310581.10	c.2353C>T	p.Pro785Ser	missense_variant	7/16	1	NM_198253.3	P2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD3 exomes AF: 0.0000121 AC: 3 AN: 247132 Hom.: 0 AF XY: 0.00000743 AC XY: 1 AN XY: 134610

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.0000873

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: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000205 AC: 3 AN: 1460468 Hom.: 0 Cov.: 32 AF XY: 0.00000275 AC XY: 2 AN XY: 726488

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000671

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: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ExAC AF: 0.0000248 AC: 3

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Idiopathic Pulmonary Fibrosis;C3151443:Dyskeratosis congenita, autosomal dominant 2 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Feb 11, 2021

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. Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt TERT protein function. This variant has not been reported in the literature in individuals with TERT-related conditions. This variant is present in population databases (rs755822641, ExAC 0.03%). This sequence change replaces proline with serine at codon 785 of the TERT protein (p.Pro785Ser). The proline residue is weakly conserved and there is a moderate physicochemical difference between proline and serine. -

Dyskeratosis congenita Benign:1

Likely benign, criteria provided, single submitter

clinical testing

Ambry Genetics

May 21, 2023

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.058
BayesDel_addAF	Benign	-0.17	T
BayesDel_noAF	Benign	-0.30
CADD	Benign	0.063
DANN	Benign	0.26
DEOGEN2	Benign	0.32	T;.
Eigen	Benign	-1.6
Eigen_PC	Benign	-1.6
FATHMM_MKL	Benign	0.0028	N
LIST_S2	Benign	0.60	T;T
M_CAP	Uncertain	0.098	D
MetaRNN	Benign	0.048	T;T
MetaSVM	Benign	-0.45	T
MutationAssessor	Benign	-1.5	N;N
MutationTaster	Benign	1.0	N;N;N;N
PrimateAI	Benign	0.30	T
PROVEAN	Benign	1.6	N;N
REVEL	Benign	0.17
Sift	Benign	0.67	T;T
Sift4G	Benign	0.90	T;T
Polyphen		0.0030	B;B
Vest4		0.18
MutPred		0.33		Gain of phosphorylation at P785 (P = 0.0699);Gain of phosphorylation at P785 (P = 0.0699);
MVP		0.39
MPC		1.0
ClinPred		0.044	T
GERP RS		-0.013
Varity_R		0.029
gMVP		0.38

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: rs755822641; hg19: chr5-1272329; COSMIC: COSV105112274;