chr5-1278665-G-C

Variant names:

• chr5-1278665-G-C
• rs778622091
• NM_198253.3:c.2262C>G

Variant summary

Our verdict is Uncertain significance. The variant received 0 ACMG points: 2P and 2B. PM2 BP4_Moderate

The NM_198253.3(TERT):​c.2262C>G​(p.His754Gln) 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. 16/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Synonymous variant affecting the same amino acid position (i.e. H754H) 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: -0.163
• 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 0 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.08110136).

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.2262C>G	p.His754Gln	missense	Exon 6 of 16	NP_937983.2
	TERT	NM_001193376.3		c.2262C>G	p.His754Gln	missense	Exon 6 of 15	NP_001180305.1
	TERT	NR_149162.3		n.2341C>G		non_coding_transcript_exon	Exon 6 of 13

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TERT	ENST00000310581.10	TSL:1 MANE Select	c.2262C>G	p.His754Gln	missense	Exon 6 of 16	ENSP00000309572.5
	TERT	ENST00000334602.10	TSL:1	c.2262C>G	p.His754Gln	missense	Exon 6 of 15	ENSP00000334346.6
	TERT	ENST00000460137.6	TSL:1	n.2226C>G		non_coding_transcript_exon	Exon 6 of 13	ENSP00000425003.1

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 32

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

Feb 21, 2022

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This sequence change replaces histidine, which is basic and polar, with glutamine, which is neutral and polar, at codon 754 of the TERT protein (p.His754Gln). This variant is not present in population databases (gnomAD no frequency). This variant has not been reported in the literature in individuals affected with TERT-related conditions. 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) performed at Invitae indicates that this missense variant is not expected to disrupt TERT protein function. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. 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 v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.12
BayesDel_addAF	Benign	-0.11	T
BayesDel_noAF	Benign	-0.40
CADD	Benign	3.0
DANN	Benign	0.50
DEOGEN2	Benign	0.33	T
Eigen	Benign	-1.2
Eigen_PC	Benign	-1.2
FATHMM_MKL	Benign	0.021	N
LIST_S2	Benign	0.52	T
M_CAP	Pathogenic	0.29	D
MetaRNN	Benign	0.081	T
MetaSVM	Uncertain	-0.24	T
MutationAssessor	Benign	-0.035	N
PhyloP100		-0.16
PrimateAI	Benign	0.31	T
PROVEAN	Benign	-0.48	N
REVEL	Benign	0.14
Sift	Benign	0.40	T
Sift4G	Benign	0.46	T
Polyphen		0.023	B
Vest4		0.12
MutPred		0.30		Gain of sheet (P = 0.0477)
MVP		0.34
MPC		1.1
ClinPred		0.059	T
GERP RS		1.5
Varity_R		0.044
gMVP		0.57
Mutation Taster		=69/31	polymorphism

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.090		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: rs778622091; hg19: chr5-1278780;