chr20-63659458-A-G

Position:

• chr20-63659458-A-G

Variant summary

Our verdict is Uncertain significance. Variant got 2 ACMG points: 2P and 0B. PM2

The NM_001283009.2(RTEL1):​c.56A>G​(p.Lys19Arg) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,862 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/22 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Uncertain significance (★). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. K19E) has been classified as Uncertain significance.

• Frequency:
  • Genomes: not found (cov: 33)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: RTEL1 NM_001283009.2 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: -0.466

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:):

ACMG classification

Verdict is Uncertain_significance. Variant got 2 ACMG points.

• PM2: Very rare variant in population databases, with high coverage

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
RTEL1	NM_001283009.2	c.56A>G	p.Lys19Arg	missense_variant	2/35	ENST00000360203.11
RTEL1-TNFRSF6B	NR_037882.1	n.883A>G		non_coding_transcript_exon_variant	2/38

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
RTEL1	ENST00000360203.11	c.56A>G	p.Lys19Arg	missense_variant	2/35	5	NM_001283009.2	A2

Frequencies

GnomAD3 genomes Cov.: 33

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461862 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727234

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.00

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.0000252

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 33

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Dyskeratosis congenita, autosomal recessive 5;C4225346:Pulmonary fibrosis and/or bone marrow failure, Telomere-related, 3 Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

Aug 12, 2021

This sequence change replaces lysine with arginine at codon 19 of the RTEL1 protein (p.Lys19Arg). The lysine residue is weakly conserved and there is a small physicochemical difference between lysine and arginine. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals affected with RTEL1-related conditions. Algorithms developed to predict the effect of missense changes on protein structure and function output the following: SIFT: "Tolerated"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0". The arginine amino acid residue is found in multiple mammalian species, which suggests that this missense change does not adversely affect protein function. Algorithms developed to predict the effect of sequence changes on RNA splicing suggest that this variant may create or strengthen a splice site. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.066
BayesDel_addAF	Benign	-0.10	T
BayesDel_noAF	Benign	-0.38
CADD	Benign	11
DANN	Uncertain	0.99
DEOGEN2	Benign	0.17	T;.;.;.;.
Eigen	Benign	-0.88
Eigen_PC	Benign	-0.81
FATHMM_MKL	Benign	0.16	N
LIST_S2	Benign	0.79	T;T;T;T;D
M_CAP	Benign	0.032	D
MetaRNN	Benign	0.085	T;T;T;T;T
MetaSVM	Benign	-0.81	T
MutationAssessor	Benign	0.49	N;N;N;.;.
MutationTaster	Benign	1.0	N;N;N;N
PrimateAI	Benign	0.20	T
PROVEAN	Benign	-1.2	N;N;N;N;.
REVEL	Benign	0.037
Sift	Benign	0.088	T;T;T;T;.
Sift4G	Benign	0.35	T;T;T;T;.
Polyphen		0.0020	B;B;B;.;.
Vest4		0.084
MutPred		0.47		Loss of methylation at K19 (P = 8e-04);Loss of methylation at K19 (P = 8e-04);Loss of methylation at K19 (P = 8e-04);Loss of methylation at K19 (P = 8e-04);Loss of methylation at K19 (P = 8e-04);
MVP		0.59
ClinPred		0.043	T
GERP RS		1.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.050
gMVP		0.36

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.41		Details are displayed if max score is > 0.2
DS_AG_spliceai		0.41		Position offset: -7

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

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr20-62290811;