NM_198253.3:c.3352G>A

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 0P and 2B. BP4_Moderate

The NM_198253.3(TERT):​c.3352G>A​(p.Ala1118Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000186 in 1,612,064 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts 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. A1118S) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)
Exomes 𝑓: 0.000020 ( 0 hom. )

Consequence

TERT
NM_198253.3 missense

Scores

1
7
11

Clinical Significance

Uncertain significance criteria provided, multiple submitters, no conflicts U:4

Conservation

PhyloP100: 1.17

Publications

0 publications found
Variant links:
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 Gene-Disease associations (from GenCC):
  • pulmonary fibrosis and/or bone marrow failure, Telomere-related, 1
    Inheritance: AD Classification: DEFINITIVE, STRONG Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics
  • dyskeratosis congenita, autosomal dominant 2
    Inheritance: AR, AD, SD, Unknown Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Ambry Genetics, G2P, Genomics England PanelApp, Labcorp Genetics (formerly Invitae), ClinGen, Laboratory for Molecular Medicine
  • acute myeloid leukemia
    Inheritance: AD Classification: STRONG, LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Genomics England PanelApp
  • dyskeratosis congenita
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • Hoyeraal-Hreidarsson syndrome
    Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
  • melanoma, cutaneous malignant, susceptibility to, 9
    Inheritance: AD Classification: LIMITED Submitted by: Labcorp Genetics (formerly Invitae), Ambry Genetics

Genome browser will be placed here

ACMG classification

Classification was made for transcript

Our verdict: Likely_benign. The variant received -2 ACMG points.

BP4
Computational evidence support a benign effect (MetaRNN=0.2580669).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
TERTNM_198253.3 linkc.3352G>A p.Ala1118Thr missense_variant Exon 16 of 16 ENST00000310581.10 NP_937983.2 O14746-1
TERTNM_001193376.3 linkc.3163G>A p.Ala1055Thr missense_variant Exon 15 of 15 NP_001180305.1 O14746-3
TERTNR_149162.3 linkn.3060G>A non_coding_transcript_exon_variant Exon 13 of 13
TERTNR_149163.3 linkn.3024G>A non_coding_transcript_exon_variant Exon 13 of 13

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
TERTENST00000310581.10 linkc.3352G>A p.Ala1118Thr missense_variant Exon 16 of 16 1 NM_198253.3 ENSP00000309572.5 O14746-1

Frequencies

GnomAD3 genomes
AF:
0.00000657
AC:
1
AN:
152244
Hom.:
0
Cov.:
33
show subpopulations
Gnomad AFR
AF:
0.00
Gnomad AMI
AF:
0.00
Gnomad AMR
AF:
0.00
Gnomad ASJ
AF:
0.00
Gnomad EAS
AF:
0.00
Gnomad SAS
AF:
0.00
Gnomad FIN
AF:
0.00
Gnomad MID
AF:
0.00
Gnomad NFE
AF:
0.0000147
Gnomad OTH
AF:
0.00
GnomAD2 exomes
AF:
0.00000820
AC:
2
AN:
244042
AF XY:
0.00000752
show subpopulations
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 FIN exome
AF:
0.00
Gnomad NFE exome
AF:
0.00000908
Gnomad OTH exome
AF:
0.00
GnomAD4 exome
AF:
0.0000199
AC:
29
AN:
1459820
Hom.:
0
Cov.:
31
AF XY:
0.0000207
AC XY:
15
AN XY:
726118
show subpopulations
African (AFR)
AF:
0.00
AC:
0
AN:
33474
American (AMR)
AF:
0.00
AC:
0
AN:
44650
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
25982
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39678
South Asian (SAS)
AF:
0.0000233
AC:
2
AN:
85886
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
52308
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5758
European-Non Finnish (NFE)
AF:
0.0000243
AC:
27
AN:
1111750
Other (OTH)
AF:
0.00
AC:
0
AN:
60334
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.497
Heterozygous variant carriers
0
2
4
7
9
11
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
AF:
0.00000657
AC:
1
AN:
152244
Hom.:
0
Cov.:
33
AF XY:
0.0000134
AC XY:
1
AN XY:
74378
show subpopulations
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
41468
American (AMR)
AF:
0.00
AC:
0
AN:
15292
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
3470
East Asian (EAS)
AF:
0.00
AC:
0
AN:
5198
South Asian (SAS)
AF:
0.00
AC:
0
AN:
4836
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
10632
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
316
European-Non Finnish (NFE)
AF:
0.0000147
AC:
1
AN:
68026
Other (OTH)
AF:
0.00
AC:
0
AN:
2094
⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000756
ExAC
AF:
0.0000331
AC:
4

ClinVar

Significance: Uncertain significance
Submissions summary: Uncertain:4
Revision: criteria provided, multiple submitters, no conflicts
LINK: link

Submissions by phenotype

Idiopathic Pulmonary Fibrosis;C3151443:Dyskeratosis congenita, autosomal dominant 2 Uncertain:1
Jan 02, 2024
Labcorp Genetics (formerly Invitae), Labcorp
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

This sequence change replaces alanine, which is neutral and non-polar, with threonine, which is neutral and polar, at codon 1118 of the TERT protein (p.Ala1118Thr). The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This variant has not been reported in the literature in individuals affected with TERT-related conditions. ClinVar contains an entry for this variant (Variation ID: 410677). 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. -

Dyskeratosis congenita, autosomal dominant 2 Uncertain:1
Nov 14, 2023
Baylor Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

- -

not provided Uncertain:1
Aug 08, 2023
Mayo Clinic Laboratories, Mayo Clinic
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

PP2 -

Dyskeratosis congenita Uncertain:1
Jul 04, 2022
Ambry Genetics
Significance:Uncertain significance
Review Status:criteria provided, single submitter
Collection Method:clinical testing

The p.A1118T variant (also known as c.3352G>A), located in coding exon 16 of the TERT gene, results from a G to A substitution at nucleotide position 3352. The alanine at codon 1118 is replaced by threonine, 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
0.11
BayesDel_addAF
Uncertain
0.080
D
BayesDel_noAF
Benign
-0.12
CADD
Benign
20
DANN
Uncertain
0.99
DEOGEN2
Uncertain
0.59
D;.
Eigen
Benign
-0.41
Eigen_PC
Benign
-0.61
FATHMM_MKL
Benign
0.059
N
LIST_S2
Benign
0.67
T;T
M_CAP
Pathogenic
0.66
D
MetaRNN
Benign
0.26
T;T
MetaSVM
Uncertain
0.59
D
MutationAssessor
Benign
2.0
M;.
PhyloP100
1.2
PrimateAI
Benign
0.40
T
PROVEAN
Benign
-1.7
N;N
REVEL
Uncertain
0.38
Sift
Uncertain
0.013
D;D
Sift4G
Uncertain
0.015
D;D
Polyphen
0.99
D;P
Vest4
0.17
MutPred
0.21
Gain of glycosylation at A1118 (P = 0.0135);.;
MVP
0.60
MPC
1.2
ClinPred
0.80
D
GERP RS
2.9
Varity_R
0.32
gMVP
0.65
Mutation Taster
=87/13
polymorphism

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

Other links and lift over

dbSNP: rs756628621; hg19: chr5-1253890; API