rs137854492

chrX-154773163-A-G

Variant summary

Our verdict is Likely pathogenic. Variant got 6 ACMG points: 6P and 0B. PM1 PM2 PP2 PP3

The NM_001363.5(DKC1):c.1069A>G(p.Thr357Ala) variant causes a missense change involving the alteration of a conserved nucleotide. The variant was absent in control chromosomes in GnomAD project. In-silico tool predicts a pathogenic 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. T357S) has been classified as Uncertain significance.

• Frequency: Genomes: not found (cov: 22)
• Consequence: DKC1 NM_001363.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter P:1 U:1
• Conservation: PhyloP100: 8.84

Genes affected

DKC1 (HGNC:2890): (dyskerin pseudouridine synthase 1) This gene functions in two distinct complexes. It plays an active role in telomerase stabilization and maintenance, as well as recognition of snoRNAs containing H/ACA sequences which provides stability during biogenesis and assembly into H/ACA small nucleolar RNA ribonucleoproteins (snoRNPs). This gene is highly conserved and widely expressed, and may play additional roles in nucleo-cytoplasmic shuttling, DNA damage response, and cell adhesion. Mutations have been associated with X-linked dyskeratosis congenita. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jan 2014]

ACMG classification

Verdict is Likely_pathogenic. Variant got 6 ACMG points.

• PM1: In a hotspot region, there are 2 aminoacids with missense pathogenic changes in the window of +-8 aminoacids around while only 0 benign, 5 uncertain in NM_001363.5
• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant where missense usually causes diseases, DKC1
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.811

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
DKC1	NM_001363.5	c.1069A>G	p.Thr357Ala	missense_variant	11/15	ENST00000369550.10

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
DKC1	ENST00000369550.10	c.1069A>G	p.Thr357Ala	missense_variant	11/15	1	NM_001363.5	P2

Frequencies

GnomAD3 genomes Cov.: 22

GnomAD4 exome Cov.: 29

GnomAD4 genome Cov.: 22

ClinVar

Significance: Uncertain significance

Submissions summary: Pathogenic:1 Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Dyskeratosis congenita, X-linked Pathogenic:1

Pathogenic, no assertion criteria provided

literature only

OMIM

May 01, 2005

- -

Dyskeratosis congenita Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Ambry Genetics

Jan 04, 2019

The p.T357A variant (also known as c.1069A>G), located in coding exon 11 of the DKC1 gene, results from an A to G substitution at nucleotide position 1069. The threonine at codon 357 is replaced by alanine, an amino acid with similar properties. This amino acid position is highly conserved in available vertebrate species. In addition, this alteration is predicted to be deleterious by in silico analysis. Based on internal structural analysis, this variant is anticipated to result in a change in protein-protein interaction. However, it does not disrupt the surface structure itself (Li S et al. EMBO J., 2011 Nov;30:5010-20). Since supporting evidence is limited at this time, the clinical significance of this alteration remains unclear. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.19
BayesDel_addAF	Pathogenic	0.62	D
BayesDel_noAF	Pathogenic	0.66
Cadd	Benign	23
Dann	Uncertain	0.99
FATHMM_MKL	Uncertain	0.96	D
LIST_S2	Uncertain	0.96	D;D
M_CAP	Pathogenic	0.87	D
MetaRNN	Pathogenic	0.81	D;D
MetaSVM	Pathogenic	0.82	D
MutationAssessor	Uncertain	2.3	M;M
MutationTaster	Benign	1.0	A
PrimateAI	Uncertain	0.67	T
Sift4G	Benign	0.25	T;T
Polyphen		0.20	.;B
Vest4		0.74
MutPred		0.32		Loss of stability (P = 0.0895);Loss of stability (P = 0.0895);
MVP		1.0
MPC		1.4
ClinPred		0.96	D
GERP RS		5.7
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		2.8
Varity_R		0.72
gMVP		0.93

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

Publications

LitVar

Other links and lift over

dbSNP: rs137854492; hg19: chrX-154001438;