5-1272247-G-C

Variant names:

• chr5-1272247-G-C
• rs770066110
• NM_198253.3:c.2320C>G

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 4P and 2B. PM1 PM2 BP4_Moderate

The NM_198253.3(TERT):​c.2320C>G​(p.Arg774Gly) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000137 in 1,460,416 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 15/22 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. R774Q) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 0.0000014 (0 hom.)
• Consequence: TERT NM_198253.3 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.0920
• Publications: 0 publications found

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

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

• PM1: In a hotspot region, there are 4 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 14 uncertain in NM_198253.3
• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.11293256).

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_198253.3. You can select a different transcript below to see updated ACMG assignments.

RefSeq Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TERT	NM_198253.3	MANE Select	c.2320C>G	p.Arg774Gly	missense	Exon 7 of 16	NP_937983.2
	TERT	NM_001193376.3		c.2320C>G	p.Arg774Gly	missense	Exon 7 of 15	NP_001180305.1
	TERT	NR_149162.3		n.2366-3614C>G		intron	N/A

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TERT	ENST00000310581.10	TSL:1 MANE Select	c.2320C>G	p.Arg774Gly	missense	Exon 7 of 16	ENSP00000309572.5
	TERT	ENST00000334602.10	TSL:1	c.2320C>G	p.Arg774Gly	missense	Exon 7 of 15	ENSP00000334346.6
	TERT	ENST00000460137.6	TSL:1	n.2251-3614C>G		intron	N/A	ENSP00000425003.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 0.00000137 AC: 2 AN: 1460416 Hom.: 0 Cov.: 32 AF XY: 0.00000138 AC XY: 1 AN XY: 726474

African (AFR) AF: 0.00 AC: 0 AN: 33460

American (AMR) AF: 0.00 AC: 0 AN: 44684

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26126

East Asian (EAS) AF: 0.00 AC: 0 AN: 39680

South Asian (SAS) AF: 0.00 AC: 0 AN: 86156

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 52396

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5766

European-Non Finnish (NFE) AF: 0.00000180 AC: 2 AN: 1111788

Other (OTH) AF: 0.00 AC: 0 AN: 60360

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Dyskeratosis congenita Uncertain:1

Feb 28, 2024

Ambry Genetics

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

The p.R774G variant (also known as c.2320C>G), located in coding exon 7 of the TERT gene, results from a C to G substitution at nucleotide position 2320. The arginine at codon 774 is replaced by glycine, an amino acid with dissimilar properties. This amino acid position is conserved. In addition, this alteration is predicted to be tolerated by in silico analysis. Based on the available evidence, the clinical significance of this alteration remains unclear.

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.090
BayesDel_addAF	Benign	-0.053	T
BayesDel_noAF	Benign	-0.31
CADD	Benign	9.1
DANN	Benign	0.79
DEOGEN2	Uncertain	0.52	D
Eigen	Benign	-1.3
Eigen_PC	Benign	-1.4
FATHMM_MKL	Benign	0.011	N
LIST_S2	Benign	0.66	T
M_CAP	Uncertain	0.26	D
MetaRNN	Benign	0.11	T
MetaSVM	Benign	-0.53	T
MutationAssessor	Benign	0.63	N
PhyloP100		0.092
PrimateAI	Benign	0.30	T
PROVEAN	Uncertain	-2.6	D
REVEL	Benign	0.26
Sift	Benign	0.21	T
Sift4G	Benign	0.20	T
Polyphen		0.0030	B
Vest4		0.16
MutPred		0.55		Gain of loop (P = 0.0195)
MVP		0.36
MPC		1.3
ClinPred		0.081	T
GERP RS		-2.8
Varity_R		0.12
gMVP		0.58
Mutation Taster		=88/12	polymorphism

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

Other links and lift over

dbSNP: rs770066110; hg19: chr5-1272362;