rs199422300

Variant names:

• chr5-1278686-GA-G
• rs199422300
• NM_198253.3:c.2240delT

Variant summary

Our verdict is Pathogenic. The variant received 16 ACMG points: 16P and 0B. PVS1 PS3 PM2 PP5_Moderate

The NM_198253.3(TERT):​c.2240delT​(p.Val747AlafsTer20) variant causes a frameshift change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Pathogenic (★). ClinVar reports functional evidence for this variant: "SCV001783391: Functional studies demonstrate decreased telomerase activity and indicate a damaging effect of c.2240delT on protein product and function (Tsakiri et al., 2007)" and additional evidence is available in ClinVar. Synonymous variant affecting the same amino acid position (i.e. V747V) has been classified as Likely benign. Variant results in nonsense mediated mRNA decay.

• Frequency: Genomes: not found (cov: 34)
• Consequence: TERT NM_198253.3 frameshift
• Clinical Significance: Pathogenic criteria provided, single submitter P:3 O:1
• Conservation: PhyloP100: 5.04
• Publications: 11 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: Pathogenic. The variant received 16 ACMG points.

• PVS1: Loss of function variant, product undergoes nonsense mediated mRNA decay. LoF is a known mechanism of disease.
• PS3: PS3 evidence extracted from ClinVar submissions: SCV001783391: Functional studies demonstrate decreased telomerase activity and indicate a damaging effect of c.2240delT on protein product and function (Tsakiri et al., 2007); PMID: 17460043
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 5-1278686-GA-G is Pathogenic according to our data. Variant chr5-1278686-GA-G is described in ClinVar as Pathogenic. ClinVar VariationId is 12737.Status of the report is criteria_provided_single_submitter, 1 stars.

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.2240delT	p.Val747AlafsTer20	frameshift	Exon 6 of 16	NP_937983.2	O14746-1
	TERT	NM_001193376.3		c.2240delT	p.Val747AlafsTer20	frameshift	Exon 6 of 15	NP_001180305.1	O14746-3
	TERT	NR_149162.3		n.2319delT		non_coding_transcript_exon	Exon 6 of 13

Ensembl Transcripts

Sel.	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	TERT	ENST00000310581.10	TSL:1 MANE Select	c.2240delT	p.Val747AlafsTer20	frameshift	Exon 6 of 16	ENSP00000309572.5	O14746-1
	TERT	ENST00000334602.10	TSL:1	c.2240delT	p.Val747AlafsTer20	frameshift	Exon 6 of 15	ENSP00000334346.6	O14746-3
	TERT	ENST00000460137.6	TSL:1	n.2204delT		non_coding_transcript_exon	Exon 6 of 13	ENSP00000425003.1	O14746-4

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Cov.: 32

GnomAD4 genome Cov.: 34

Alfa AF: 0.00 Hom.: 0

Bravo AF: 0.00000378

ClinVar

ClinVar submissions

Significance: Pathogenic

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
1	-	-	not provided (1)
1	-	-	Pulmonary fibrosis and/or bone marrow failure, Telomere-related, 1 (1)
-	-	-	Interstitial lung disease 2 (1)
-	-	-	Pulmonary fibrosis (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
PhyloP100		5.0
Mutation Taster		=4/196	disease causing (ClinVar)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.040		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: rs199422300; hg19: chr5-1278801;