rs876658018

Positions:

• chr5-1268527-G-A
• chr5-1268527-G-T

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 4P and 0B. PM1 PM2

The NM_198253.3(TERT):​c.2575C>T​(p.Arg859Trp) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,460,968 control chromosomes in the GnomAD database, with no homozygous occurrence. 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. R859Q) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TERT NM_198253.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 1.93

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 Uncertain_significance. Variant got 4 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 6 uncertain in NM_198253.3
• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TERT	NM_198253.3	c.2575C>T	p.Arg859Trp	missense_variant	9/16	ENST00000310581.10
TERT	NM_001193376.3	c.2575C>T	p.Arg859Trp	missense_variant	9/15
TERT	NR_149162.3	n.2472C>T		non_coding_transcript_exon_variant	7/13
TERT	NR_149163.3	n.2436C>T		non_coding_transcript_exon_variant	7/13

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TERT	ENST00000310581.10	c.2575C>T	p.Arg859Trp	missense_variant	9/16	1	NM_198253.3	P2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1460968 Hom.: 0 Cov.: 30 AF XY: 0.00000138 AC XY: 1 AN XY: 726754

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: 0.00

GnomAD4 genome Cov.: 33

Bravo AF: 0.00000756

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

Submissions by phenotype

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Laboratory for Molecular Medicine, Mass General Brigham Personalized Medicine

Apr 15, 2015

The p.Arg859Trp variant in TERT has not been previously reported in individuals with pulmonary disease or in large population studies. Computational prediction tools and conservation analysis do not provide strong support for or against an impact to the protein, though Arginine (Arg) at residue 859 is not well conserve d. In summary, the clinical significance of the p.Arg859Trp variant is uncertain . -

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

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Apr 29, 2023

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) has been performed at Invitae for this missense variant, however the output from this modeling did not meet the statistical confidence thresholds required to predict the impact of this variant on TERT protein function. 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. ClinVar contains an entry for this variant (Variation ID: 229310). This variant has not been reported in the literature in individuals affected with TERT-related conditions. This variant is not present in population databases (gnomAD no frequency). This sequence change replaces arginine, which is basic and polar, with tryptophan, which is neutral and slightly polar, at codon 859 of the TERT protein (p.Arg859Trp). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Uncertain	0.036	T
BayesDel_noAF	Uncertain	-0.080
CADD	Uncertain	25
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.94	D;.
Eigen	Benign	-0.15
Eigen_PC	Benign	-0.27
FATHMM_MKL	Benign	0.66	D
LIST_S2	Uncertain	0.90	D;D
M_CAP	Pathogenic	0.81	D
MetaRNN	Uncertain	0.60	D;D
MetaSVM	Uncertain	0.58	D
MutationAssessor	Benign	1.5	L;L
MutationTaster	Benign	0.91	N;N;N;N
PrimateAI	Benign	0.21	T
PROVEAN	Uncertain	-3.0	D;D
REVEL	Uncertain	0.34
Sift	Uncertain	0.0060	D;D
Sift4G	Uncertain	0.0090	D;D
Polyphen		1.0	D;D
Vest4		0.27
MutPred		0.47		Gain of helix (P = 0.062);Gain of helix (P = 0.062);
MVP		0.85
MPC		2.1
ClinPred		0.88	D
GERP RS		2.1
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Varity_R		0.20
gMVP		0.62

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.15		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: rs876658018; hg19: chr5-1268642;