rs1554043101

chr5-1294585-A-C

Variant summary

Our verdict is Uncertain significance. Variant got 5 ACMG points: 5P and 0B. PM1 PM2 PP3

The NM_198253.3(TERT):c.301T>G(p.Phe101Val) 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 pathogenic outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. F101F) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 34)
• Consequence: TERT NM_198253.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 3.22

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 5 ACMG points.

• PM1: In a hotspot region, there are 3 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 13 uncertain in NM_198253.3
• PM2: Very rare variant in population databases, with high coverage
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.774

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
TERT	NM_198253.3	c.301T>G	p.Phe101Val	missense_variant	2/16	ENST00000310581.10
TERT	NM_001193376.3	c.301T>G	p.Phe101Val	missense_variant	2/15
TERT	NR_149162.3	n.380T>G		non_coding_transcript_exon_variant	2/13
TERT	NR_149163.3	n.380T>G		non_coding_transcript_exon_variant	2/13

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
TERT	ENST00000310581.10	c.301T>G	p.Phe101Val	missense_variant	2/16	1	NM_198253.3	P2
TERT	ENST00000334602.10	c.301T>G	p.Phe101Val	missense_variant	2/15	1		A2
TERT	ENST00000460137.6	c.301T>G	p.Phe101Val	missense_variant, NMD_transcript_variant	2/13	1
TERT	ENST00000656021.1	c.301T>G	p.Phe101Val	missense_variant, NMD_transcript_variant	2/17

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 35

GnomAD4 genome Cov.: 34

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

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

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Nov 28, 2017

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 do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Probably Damaging"; Align-GVGD: "Class C0"). This variant has not been reported in the literature in individuals with TERT-related disease. This variant is not present in population databases (ExAC no frequency). This sequence change replaces phenylalanine with valine at codon 101 of the TERT protein (p.Phe101Val). The phenylalanine residue is weakly conserved and there is a small physicochemical difference between phenylalanine and valine. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.86
BayesDel_addAF	Pathogenic	0.22	D
BayesDel_noAF	Uncertain	0.080
Cadd	Uncertain	25
Dann	Uncertain	0.98
DEOGEN2	Pathogenic	0.91	D;.
Eigen	Uncertain	0.22
Eigen_PC	Benign	0.20
FATHMM_MKL	Benign	0.35	N
LIST_S2	Benign	0.86	D;D
M_CAP	Pathogenic	0.98	D
MetaRNN	Pathogenic	0.77	D;D
MetaSVM	Pathogenic	0.87	D
MutationAssessor	Uncertain	2.2	M;M
MutationTaster	Benign	0.50	N;N;N;N
PrimateAI	Pathogenic	0.94	D
PROVEAN	Uncertain	-4.0	D;D
REVEL	Pathogenic	0.73
Sift	Uncertain	0.0050	D;D
Sift4G	Uncertain	0.0040	D;D
Polyphen		0.90	P;P
Vest4		0.32
MutPred		0.66		Gain of MoRF binding (P = 0.0792);Gain of MoRF binding (P = 0.0792);
MVP		0.81
MPC		2.4
ClinPred		0.99	D
GERP RS		3.5
Varity_R		0.48
gMVP		0.96

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: rs1554043101; hg19: chr5-1294700;