chr5-1294442-C-A

Variant names:

• chr5-1294442-C-A
• rs1314321999
• NM_198253.3:c.444G>T

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Moderate BP6 BP7

The NM_198253.3(TERT):​c.444G>T​(p.Val148Val) variant causes a synonymous 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. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Synonymous variant affecting the same amino acid position (i.e. V148V) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 34)
  • Exomes 𝑓: 0.0 (0 hom.)
  • Failed GnomAD Quality Control
• Consequence: TERT NM_198253.3 synonymous
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:1 B:1
• Conservation: PhyloP100: 0.554
• 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: Likely_benign. The variant received -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (BayesDel_noAF=-0.31).
• BP6: Variant 5-1294442-C-A is Benign according to our data. Variant chr5-1294442-C-A is described in ClinVar as Conflicting_classifications_of_pathogenicity. ClinVar VariationId is 2505664.
• BP7: Synonymous conserved (PhyloP=0.554 with no splicing effect.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
TERT	NM_198253.3	c.444G>T	p.Val148Val	synonymous_variant	Exon 2 of 16	ENST00000310581.10	NP_937983.2
TERT	NM_001193376.3	c.444G>T	p.Val148Val	synonymous_variant	Exon 2 of 15		NP_001180305.1
TERT	NR_149162.3	n.523G>T		non_coding_transcript_exon_variant	Exon 2 of 13
TERT	NR_149163.3	n.523G>T		non_coding_transcript_exon_variant	Exon 2 of 13

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
TERT	ENST00000310581.10	c.444G>T	p.Val148Val	synonymous_variant	Exon 2 of 16	1	NM_198253.3	ENSP00000309572.5
TERT	ENST00000334602.10	c.444G>T	p.Val148Val	synonymous_variant	Exon 2 of 15	1		ENSP00000334346.6
TERT	ENST00000460137.6	n.444G>T		non_coding_transcript_exon_variant	Exon 2 of 13	1		ENSP00000425003.1
TERT	ENST00000656021.1	n.444G>T		non_coding_transcript_exon_variant	Exon 2 of 17			ENSP00000499759.1

Frequencies

GnomAD3 genomes Cov.: 34

GnomAD4 exome Data not reliable, filtered out with message: AC0 AF: 0.00 AC: 0 AN: 1439980 Hom.: 0 Cov.: 35 AF XY: 0.00 AC XY: 0 AN XY: 716318

African (AFR) AF: 0.00 AC: 0 AN: 33322

American (AMR) AF: 0.00 AC: 0 AN: 44126

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 25948

East Asian (EAS) AF: 0.00 AC: 0 AN: 39438

South Asian (SAS) AF: 0.00 AC: 0 AN: 85394

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 37092

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5560

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 1109202

Other (OTH) AF: 0.00 AC: 0 AN: 59898

GnomAD4 genome Cov.: 34

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:1 Benign:1

Revision: criteria provided, conflicting classifications

Submissions by phenotype

not provided Uncertain:1

Dec 19, 2022

GeneDx

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this variant does not alter splicing; Has not been previously published as pathogenic or benign to our knowledge -

Dyskeratosis congenita Benign:1

Jul 13, 2024

Ambry Genetics

Significance: Likely benign

Review Status: criteria provided, single submitter

Collection Method: clinical testing

This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.31
CADD	Benign	13
DANN	Benign	0.77
PhyloP100		0.55
Mutation Taster		=100/0	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

Other links and lift over

dbSNP: rs1314321999; hg19: chr5-1294557;