5-1260509-G-C

Variant names:

• chr5-1260509-G-C
• rs199422305
• NM_198253.3:c.2935C>G

Variant summary

Our verdict is Likely pathogenic. The variant received 7 ACMG points: 7P and 0B. PM1 PM2 PM5 PP3

The NM_198253.3(TERT):​c.2935C>G​(p.Arg979Gly) 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. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R979Q) has been classified as Likely pathogenic.

• Frequency: Genomes: not found (cov: 33)
• Consequence: TERT NM_198253.3 missense
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 0.839
• 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: PanelApp Australia, Labcorp Genetics (formerly Invitae), Ambry Genetics
• dyskeratosis congenita, autosomal dominant 2

  Inheritance: Unknown, SD, AD, AR Classification: DEFINITIVE, STRONG, MODERATE Submitted by: Laboratory for Molecular Medicine, ClinGen, Genomics England PanelApp, G2P, Ambry Genetics, Labcorp Genetics (formerly Invitae), PanelApp Australia
• acute myeloid leukemia

  Inheritance: AD Classification: STRONG, LIMITED Submitted by: Genomics England PanelApp, Labcorp Genetics (formerly Invitae)
• 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: Ambry Genetics, Labcorp Genetics (formerly Invitae)

ACMG classification

Our verdict: Likely_pathogenic. The variant received 7 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 1 benign, 17 uncertain in NM_198253.3
• PM2: Very rare variant in population databases, with high coverage
• PM5: Other missense variant is known to change same aminoacid residue: Variant chr5-1260508-C-T is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 506255.
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.775

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

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TERT	NM_198253.3	MANE Select	c.2935C>G	p.Arg979Gly	missense	Exon 12 of 16	NP_937983.2	O14746-1
	TERT	NM_001193376.3		c.2746C>G	p.Arg916Gly	missense	Exon 11 of 15	NP_001180305.1	O14746-3
	TERT	NR_149162.3		n.2643C>G		non_coding_transcript_exon	Exon 9 of 13

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TERT	ENST00000310581.10	TSL:1 MANE Select	c.2935C>G	p.Arg979Gly	missense	Exon 12 of 16	ENSP00000309572.5	O14746-1
	TERT	ENST00000334602.10	TSL:1	c.2746C>G	p.Arg916Gly	missense	Exon 11 of 15	ENSP00000334346.6	O14746-3
	TERT	ENST00000460137.6	TSL:1	n.*140C>G		non_coding_transcript_exon	Exon 9 of 13	ENSP00000425003.1	O14746-4

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 33

GnomAD4 genome Cov.: 33

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.22
BayesDel_addAF	Uncertain	0.019	T
BayesDel_noAF	Benign	-0.21
CADD	Benign	22
DANN	Uncertain	1.0
DEOGEN2	Pathogenic	0.88	D
Eigen	Benign	0.15
Eigen_PC	Benign	0.015
FATHMM_MKL	Benign	0.74	D
LIST_S2	Uncertain	0.91	D
M_CAP	Pathogenic	0.37	D
MetaRNN	Pathogenic	0.78	D
MetaSVM	Uncertain	-0.21	T
MutationAssessor	Uncertain	2.6	M
PhyloP100		0.84
PrimateAI	Benign	0.30	T
PROVEAN	Pathogenic	-4.6	D
REVEL	Uncertain	0.50
Sift	Uncertain	0.0030	D
Sift4G	Uncertain	0.0030	D
Polyphen		0.99	D
Vest4		0.58
MutPred		0.65		Loss of methylation at R979 (P = 0.0123)
MVP		0.74
MPC		2.4
ClinPred		0.97	D
GERP RS		1.3
Varity_R		0.62
gMVP		0.71
Mutation Taster		=37/63	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs199422305; hg19: chr5-1260624;