5-1279410-G-C

Variant names:

• chr5-1279410-G-C
• rs1060503011
• NM_198253.3:c.2011C>G

Variant summary

Our verdict is Uncertain significance. Variant got 4 ACMG points: 5P and 1B. PM2 PM5 PP5 BP4

The NM_198253.3(TERT):​c.2011C>G​(p.Arg671Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts 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. R671W) has been classified as Pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: TERT NM_198253.3 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications P:1 U:1
• Conservation: PhyloP100: 0.403

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.

• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr5-1279410-G-A is described in Lovd as [Pathogenic].
• PP5: Variant 5-1279410-G-C is Pathogenic according to our data. Variant chr5-1279410-G-C is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 436994.We mark this variant Likely_pathogenic, oryginal submissions are: {Uncertain_significance=1, Likely_pathogenic=1}.
• BP4: Computational evidence support a benign effect (MetaRNN=0.34420618). . Strength limited to SUPPORTING due to the PP5.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TERT	NM_198253.3	c.2011C>G	p.Arg671Gly	missense_variant	Exon 5 of 16	ENST00000310581.10	NP_937983.2
TERT	NM_001193376.3	c.2011C>G	p.Arg671Gly	missense_variant	Exon 5 of 15		NP_001180305.1
TERT	NR_149162.3	n.2090C>G		non_coding_transcript_exon_variant	Exon 5 of 13
TERT	NR_149163.3	n.2090C>G		non_coding_transcript_exon_variant	Exon 5 of 13

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TERT	ENST00000310581.10	c.2011C>G	p.Arg671Gly	missense_variant	Exon 5 of 16	1	NM_198253.3	ENSP00000309572.5

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Dyskeratosis congenita Pathogenic:1

May 18, 2017

Genetic Services Laboratory, University of Chicago

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

- -

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

Apr 16, 2021

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This variant has not been reported in the literature in individuals with TERT-related conditions. ClinVar contains an entry for this variant (Variation ID: 436994). This sequence change replaces arginine with glycine at codon 671 of the TERT protein (p.Arg671Gly). The arginine residue is weakly conserved and there is a moderate physicochemical difference between arginine and glycine. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate insufficient coverage at this position in the ExAC database. 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 tolerated, but these predictions have not been confirmed by published functional studies and their clinical significance is uncertain. 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. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.11
BayesDel_addAF	Uncertain	0.13	D
BayesDel_noAF	Uncertain	-0.050
CADD	Benign	14
DANN	Uncertain	0.98
DEOGEN2	Pathogenic	0.87	D;.
Eigen	Benign	-0.56
Eigen_PC	Benign	-0.72
FATHMM_MKL	Benign	0.025	N
LIST_S2	Benign	0.79	T;T
M_CAP	Pathogenic	0.51	D
MetaRNN	Benign	0.34	T;T
MetaSVM	Uncertain	0.24	D
MutationAssessor	Uncertain	2.5	M;M
PrimateAI	Benign	0.37	T
PROVEAN	Uncertain	-2.9	D;D
REVEL	Uncertain	0.46
Sift	Benign	0.21	T;T
Sift4G	Benign	0.12	T;T
Polyphen		0.77	P;P
Vest4		0.31
MutPred		0.49		Gain of relative solvent accessibility (P = 0.0275);Gain of relative solvent accessibility (P = 0.0275);
MVP		0.73
MPC		1.8
ClinPred		0.68	D
GERP RS		1.8
Varity_R		0.11
gMVP		0.72

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: rs1060503011; hg19: chr5-1279525;