20-63691841-C-G

Variant names:

• chr20-63691841-C-G
• rs374540895
• NM_001283009.2:c.2652+4C>G

Variant summary

Our verdict is Likely benign. The variant received -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_001283009.2(RTEL1):​c.2652+4C>G variant causes a splice region, intron change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000124 in 1,607,466 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 2/3 splice prediction tools predict no significant impact on normal splicing. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar.

• Frequency:
  • Genomes: 𝑓 0.0000066 (0 hom., cov: 33)
  • Exomes 𝑓: 6.9e-7 (0 hom.)
• Consequence: RTEL1 NM_001283009.2 splice_region, intron
• Scores: Splicing: ADA: 0.00003383
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: -2.49
• 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_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=-0.88).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
RTEL1	NM_001283009.2	c.2652+4C>G		splice_region_variant, intron_variant	Intron 28 of 34	ENST00000360203.11	NP_001269938.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
RTEL1	ENST00000360203.11	c.2652+4C>G		splice_region_variant, intron_variant	Intron 28 of 34	5	NM_001283009.2	ENSP00000353332.5
RTEL1	ENST00000508582.7	c.2724+4C>G		splice_region_variant, intron_variant	Intron 28 of 34	2		ENSP00000424307.2
RTEL1	ENST00000370018.7	c.2652+4C>G		splice_region_variant, intron_variant	Intron 28 of 34	1		ENSP00000359035.3
RTEL1-TNFRSF6B	ENST00000492259.6	n.*254+4C>G		splice_region_variant, intron_variant	Intron 25 of 34	5		ENSP00000457428.1

Frequencies

GnomAD3 genomes AF: 0.00000658 AC: 1 AN: 152074 Hom.: 0 Cov.: 33

Gnomad AFR AF: 0.00

Gnomad AMI AF: 0.00

Gnomad AMR AF: 0.00

Gnomad ASJ AF: 0.00

Gnomad EAS AF: 0.000193

Gnomad SAS AF: 0.00

Gnomad FIN AF: 0.00

Gnomad MID AF: 0.00

Gnomad NFE AF: 0.00

Gnomad OTH AF: 0.00

GnomAD2 exomes AF: 0.00000410 AC: 1 AN: 244174 AF XY: 0.00000751

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.00

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.0000545

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 6.87e-7 AC: 1 AN: 1455274 Hom.: 0 Cov.: 30 AF XY: 0.00 AC XY: 0 AN XY: 724202

African (AFR) AF: 0.00 AC: 0 AN: 33442

American (AMR) AF: 0.00 AC: 0 AN: 44694

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 26120

East Asian (EAS) AF: 0.00 AC: 0 AN: 39686

South Asian (SAS) AF: 0.00 AC: 0 AN: 86218

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 48692

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 5744

European-Non Finnish (NFE) AF: 9.01e-7 AC: 1 AN: 1110396

Other (OTH) AF: 0.00 AC: 0 AN: 60282

GnomAD4 genome AF: 0.00000657 AC: 1 AN: 152192 Hom.: 0 Cov.: 33 AF XY: 0.0000134 AC XY: 1 AN XY: 74406

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5.

African (AFR) AF: 0.00 AC: 0 AN: 41542

American (AMR) AF: 0.00 AC: 0 AN: 15300

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 3470

East Asian (EAS) AF: 0.000194 AC: 1 AN: 5158

South Asian (SAS) AF: 0.00 AC: 0 AN: 4814

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 10602

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 294

European-Non Finnish (NFE) AF: 0.00 AC: 0 AN: 67988

Other (OTH) AF: 0.00 AC: 0 AN: 2112

⚠️ The allele balance in gnomAD version 4 Genomes is significantly skewed from the expected value of 0.5. (p-value = 0), which strongly suggests a high chance of mosaicism in these individuals.

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_noAF	Benign	-0.88
CADD	Benign	0.034
DANN	Benign	0.56
PhyloP100		-2.5

Splicing

Name	Calibrated prediction	Score	Prediction
dbscSNV1_ADA	Benign	0.000034
dbscSNV1_RF	Benign	0.10
SpliceAI score (max)		0.50		Details are displayed if max score is > 0.2
DS_DG_spliceai		0.50		Position offset: 0

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

Other links and lift over

dbSNP: rs374540895; hg19: chr20-62323194;