20-63690442-G-T

Variant names:

• chr20-63690442-G-T
• rs776744306
• NM_001283009.2:c.2413+1G>T

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PVS1_Moderate PM2 PP5_Moderate

The NM_001283009.2(RTEL1):​c.2413+1G>T variant causes a splice donor, intron 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. 3/3 splice prediction tools predicting alterations to normal splicing. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: RTEL1 NM_001283009.2 splice_donor, intron
• Scores: Splicing: ADA: 1.000
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 3.02
• Publications: 0 publications found

Genes affected

RTEL1 (HGNC:15888): (regulator of telomere elongation helicase 1) This gene encodes a DNA helicase which functions in the stability, protection and elongation of telomeres and interacts with proteins in the shelterin complex known to protect telomeres during DNA replication. Mutations in this gene have been associated with dyskeratosis congenita and Hoyerall-Hreidarsson syndrome. Read-through transcription of this gene into the neighboring downstream gene, which encodes tumor necrosis factor receptor superfamily, member 6b, generates a non-coding transcript. Alternative splicing results in multiple transcript variants encoding different isoforms. [provided by RefSeq, Sep 2013]

RTEL1-TNFRSF6B (HGNC:44095): (RTEL1-TNFRSF6B readthrough (NMD candidate)) This locus represents naturally occurring read-through transcription between the neighboring RTEL1 (regulator of telomere elongation helicase 1) and TNFRSF6B (tumor necrosis factor receptor superfamily, member 6b, decoy) genes on chromosome 20. The read-through transcript is a candidate for nonsense-mediated mRNA decay (NMD), and is unlikely to produce a protein product. [provided by RefSeq, Feb 2011]

ACMG classification

Our verdict: Likely_pathogenic. The variant received 6 ACMG points.

• PVS1: Splicing +-2 bp (donor or acceptor) variant, product NOT destroyed by NMD, known LOF gene, truncates exone, which is 0.037919547 fraction of the gene. Cryptic splice site detected, with MaxEntScore 3.3, offset of 27, new splice context is: gcgGTgtgg. Cryptic site results in inframe change. If cryptic site found is not functional and variant results in exon loss, it results in frameshift change.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 20-63690442-G-T is Pathogenic according to our data. Variant chr20-63690442-G-T is described in ClinVar as Likely_pathogenic. ClinVar VariationId is 2951618.Status of the report is criteria_provided_single_submitter, 1 stars.

Variant Effect in Transcripts

ACMG analysis was done for transcript: NM_001283009.2. 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
	RTEL1	NM_001283009.2	MANE Select	c.2413+1G>T		splice_donor intron	N/A	NP_001269938.1
	RTEL1	NM_032957.5		c.2485+1G>T		splice_donor intron	N/A	NP_116575.3
	RTEL1	NM_016434.4		c.2413+1G>T		splice_donor intron	N/A	NP_057518.1

Ensembl Transcripts

Selected	Gene	Transcript	Tags	HGVSc	HGVSp	Effect	Exon Rank	Protein	UniProt
	RTEL1	ENST00000360203.11	TSL:5 MANE Select	c.2413+1G>T		splice_donor intron	N/A	ENSP00000353332.5
	RTEL1	ENST00000508582.7	TSL:2	c.2485+1G>T		splice_donor intron	N/A	ENSP00000424307.2
	RTEL1	ENST00000370018.7	TSL:1	c.2413+1G>T		splice_donor intron	N/A	ENSP00000359035.3

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 51

GnomAD4 genome Cov.: 33

ClinVar

ClinVar submissions as Germline

Significance: Likely pathogenic

Revision: criteria provided, single submitter

Pathogenic	VUS	Benign	Condition
1	-	-	Dyskeratosis congenita, autosomal recessive 5;C4225346:Pulmonary fibrosis and/or bone marrow failure, Telomere-related, 3 (1)

Computational scores

Source: dbNSFP v4.9

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Benign	-0.20
CADD	Pathogenic	33
DANN	Uncertain	0.99
Eigen	Pathogenic	0.80
Eigen_PC	Uncertain	0.55
FATHMM_MKL	Uncertain	0.88	D
PhyloP100		3.0
GERP RS		4.2
Mutation Taster		=0/100	disease causing

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Pathogenic	1.0
dbscSNV1_RF	Pathogenic	0.93
SpliceAI score (max)		1.0		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.81		Position offset: -9
DS_DL_spliceai		1.0		Position offset: -1

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Other links and lift over

dbSNP: rs776744306; hg19: chr20-62321795;