rs878855304

Positions:

• chr5-1255379-T-A
• chr5-1255379-T-C

Variant summary

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

The ENST00000310581.10(TERT):​c.3065A>T​(p.His1022Leu) 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 1,461,870 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 (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. H1022R) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: TERT ENST00000310581.10 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.211

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]

(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=0.20161095).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
TERT	NM_198253.3	c.3065A>T	p.His1022Leu	missense_variant	14/16	ENST00000310581.10	NP_937983.2
TERT	NM_001193376.3	c.2876A>T	p.His959Leu	missense_variant	13/15		NP_001180305.1
TERT	NR_149162.3	n.2773A>T		non_coding_transcript_exon_variant	11/13
TERT	NR_149163.3	n.2737A>T		non_coding_transcript_exon_variant	11/13

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
TERT	ENST00000310581.10	c.3065A>T	p.His1022Leu	missense_variant	14/16	1	NM_198253.3	ENSP00000309572	P2
	ENST00000666708.1	n.422T>A		non_coding_transcript_exon_variant	3/3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461870 Hom.: 0 Cov.: 32 AF XY: 0.00 AC XY: 0 AN XY: 727238

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

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

Labcorp Genetics (formerly Invitae), Labcorp

Aug 09, 2022

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 are either unavailable or do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). ClinVar contains an entry for this variant (Variation ID: 242236). 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 histidine, which is basic and polar, with leucine, which is neutral and non-polar, at codon 1022 of the TERT protein (p.His1022Leu). -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.15
BayesDel_addAF	Uncertain	0.044	T
BayesDel_noAF	Benign	-0.17
CADD	Benign	3.0
DANN	Benign	0.74
DEOGEN2	Uncertain	0.57	D;.
Eigen	Benign	-1.2
Eigen_PC	Benign	-1.3
FATHMM_MKL	Benign	0.048	N
LIST_S2	Benign	0.74	T;T
M_CAP	Pathogenic	0.34	D
MetaRNN	Benign	0.20	T;T
MetaSVM	Uncertain	-0.21	T
MutationAssessor	Benign	0.0	N;.
MutationTaster	Benign	1.0	N;N;N
PrimateAI	Benign	0.27	T
PROVEAN	Uncertain	-3.0	D;D
REVEL	Uncertain	0.32
Sift	Uncertain	0.023	D;D
Sift4G	Uncertain	0.014	D;D
Polyphen		0.36	B;B
Vest4		0.23
MutPred		0.54		Gain of sheet (P = 0.0477);.;
MVP		0.52
MPC		1.4
ClinPred		0.097	T
GERP RS		-0.57
Varity_R		0.27
gMVP		0.20

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		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: rs878855304; hg19: chr5-1255494;