5-1293558-G-C

Position:

• chr5-1293558-G-C

Variant summary

Our verdict is Uncertain significance. Variant got 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_198253.3(TERT):​c.1328C>G​(p.Thr443Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000645 in 1,395,336 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 12/21 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★★).

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.0000065 (0 hom.)
• Consequence: TERT NM_198253.3 missense
• Clinical Significance: Uncertain significance criteria provided, multiple submitters, no conflicts U:2
• Conservation: PhyloP100: 1.49

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]

TERT (HGNC:):

ACMG classification

Verdict is Uncertain_significance. Variant got 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.16406778).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TERT	NM_198253.3	c.1328C>G	p.Thr443Arg	missense_variant	2/16	ENST00000310581.10	NP_937983.2
TERT	NM_001193376.3	c.1328C>G	p.Thr443Arg	missense_variant	2/15		NP_001180305.1
TERT	NR_149162.3	n.1407C>G		non_coding_transcript_exon_variant	2/13
TERT	NR_149163.3	n.1407C>G		non_coding_transcript_exon_variant	2/13

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TERT	ENST00000310581.10	c.1328C>G	p.Thr443Arg	missense_variant	2/16	1	NM_198253.3	ENSP00000309572.5
TERT	ENST00000334602.10	c.1328C>G	p.Thr443Arg	missense_variant	2/15	1		ENSP00000334346.6
TERT	ENST00000460137.6	n.1328C>G		non_coding_transcript_exon_variant	2/13	1		ENSP00000425003.1
TERT	ENST00000656021.1	n.1328C>G		non_coding_transcript_exon_variant	2/17			ENSP00000499759.1

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD3 exomes AF: 0.00000667 AC: 1 AN: 149842 Hom.: 0 AF XY: 0.0000124 AC XY: 1 AN XY: 80364

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: 0.0000176

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000645 AC: 9 AN: 1395336 Hom.: 0 Cov.: 32 AF XY: 0.00000727 AC XY: 5 AN XY: 687504

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: 0.00000743

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 34

ExAC AF: 0.00000970 AC: 1

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:2

Revision: criteria provided, multiple submitters, no conflicts

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

Apr 17, 2023

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) 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. ClinVar contains an entry for this variant (Variation ID: 242214). This variant has not been reported in the literature in individuals affected with TERT-related conditions. This variant is present in population databases (rs772257175, gnomAD 0.002%). This sequence change replaces threonine, which is neutral and polar, with arginine, which is basic and polar, at codon 443 of the TERT protein (p.Thr443Arg). -

Dyskeratosis congenita Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jun 13, 2022

The p.T443R variant (also known as c.1328C>G), located in coding exon 2 of the TERT gene, results from a C to G substitution at nucleotide position 1328. The threonine at codon 443 is replaced by arginine, an amino acid with similar properties. This amino acid position is conserved. In addition, the in silico prediction for this alteration is inconclusive. Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.078
BayesDel_addAF	Uncertain	0.040	T
BayesDel_noAF	Benign	-0.17
CADD	Benign	12
DANN	Uncertain	0.98
DEOGEN2	Uncertain	0.46	T;.
Eigen	Benign	-0.68
Eigen_PC	Benign	-0.78
FATHMM_MKL	Benign	0.093	N
LIST_S2	Benign	0.62	T;T
M_CAP	Pathogenic	0.64	D
MetaRNN	Benign	0.16	T;T
MetaSVM	Uncertain	0.17	D
MutationAssessor	Benign	1.5	L;L
PrimateAI	Uncertain	0.59	T
PROVEAN	Benign	-1.6	N;N
REVEL	Benign	0.23
Sift	Uncertain	0.011	D;D
Sift4G	Benign	0.068	T;T
Polyphen		0.89	P;B
Vest4		0.082
MutPred		0.33		Loss of phosphorylation at T443 (P = 0.024);Loss of phosphorylation at T443 (P = 0.024);
MVP		0.56
MPC		1.5
ClinPred		0.10	T
GERP RS		2.6
Varity_R		0.076
gMVP		0.24

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: rs772257175; hg19: chr5-1293673;