chr20-63659457-A-G

Position:

• chr20-63659457-A-G

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2 BP4_Strong

The NM_001283009.2(RTEL1):​c.55A>G​(p.Lys19Glu) 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 benign outcome for this variant. 15/20 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 33)
• Consequence: RTEL1 NM_001283009.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 0.175

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

Verdict is Likely_benign. Variant got -2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.047740906).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
RTEL1	NM_001283009.2	c.55A>G	p.Lys19Glu	missense_variant	2/35	ENST00000360203.11	NP_001269938.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
RTEL1	ENST00000360203.11	c.55A>G	p.Lys19Glu	missense_variant	2/35	5	NM_001283009.2	ENSP00000353332.5
RTEL1	ENST00000508582.7	c.55A>G	p.Lys19Glu	missense_variant	2/35	2		ENSP00000424307.2
RTEL1	ENST00000370018.7	c.55A>G	p.Lys19Glu	missense_variant	2/35	1		ENSP00000359035.3
RTEL1-TNFRSF6B	ENST00000492259.6	n.55A>G		non_coding_transcript_exon_variant	1/35	5		ENSP00000457428.1

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Inborn genetic diseases Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Sep 14, 2022

The c.55A>G (p.K19E) alteration is located in exon 2 (coding exon 1) of the RTEL1 gene. This alteration results from a A to G substitution at nucleotide position 55, causing the lysine (K) at amino acid position 19 to be replaced by a glutamic acid (E). Based on insufficient or conflicting evidence, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.073
BayesDel_addAF	Benign	-0.068	T
BayesDel_noAF	Benign	-0.34
CADD	Benign	11
DANN	Benign	0.94
DEOGEN2	Benign	0.077	T;.;.;.;.
Eigen	Benign	-0.87
Eigen_PC	Benign	-0.77
FATHMM_MKL	Benign	0.12	N
LIST_S2	Benign	0.79	T;T;T;D;D
M_CAP	Benign	0.034	D
MetaRNN	Benign	0.048	T;T;T;T;T
MetaSVM	Benign	-0.96	T
MutationAssessor	Benign	-0.14	N;N;N;.;.
PrimateAI	Benign	0.21	T
PROVEAN	Benign	-0.47	N;N;N;N;.
REVEL	Benign	0.031
Sift	Benign	0.56	T;T;T;T;.
Sift4G	Benign	1.0	T;T;T;T;.
Polyphen		0.0010	B;B;B;.;.
Vest4		0.082
MutPred		0.47		Loss of methylation at K19 (P = 0);Loss of methylation at K19 (P = 0);Loss of methylation at K19 (P = 0);Loss of methylation at K19 (P = 0);Loss of methylation at K19 (P = 0);
MVP		0.55
ClinPred		0.075	T
GERP RS		1.4
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.090
gMVP		0.42

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.080		Details are displayed if max score is > 0.2

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

Publications

LitVar

Other links and lift over

dbSNP: rs2089973799; hg19: chr20-62290810;