X-154776193-C-T

Variant names:

• chrX-154776193-C-T
• rs878853071
• NM_001363.5:c.1345C>T

Variant summary

Our verdict is Uncertain significance. The variant received 2 ACMG points: 2P and 0B. PM2

The NM_001363.5(DKC1):​c.1345C>T​(p.Arg449*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000911 in 1,097,717 control chromosomes in the GnomAD database, with no homozygous occurrence. There are no hemizygote samples in GnomAD. In-silico tool predicts a pathogenic outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Variant results in nonsense mediated mRNA decay.

• Frequency:
  • Genomes: not found (cov: 23)
  • Exomes 𝑓: 9.1e-7 (0 hom. 0 hem.)
• Consequence: DKC1 NM_001363.5 stop_gained
• Clinical Significance: Not reported in ClinVar
• Conservation: PhyloP100: 2.18
• Publications: 0 publications found

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]

DKC1 Gene-Disease associations (from GenCC):

• DKC1-related disorder

  Inheritance: XL Classification: DEFINITIVE Submitted by: ClinGen
• dyskeratosis congenita, X-linked

  Inheritance: XL Classification: DEFINITIVE, STRONG Submitted by: ClinGen, Labcorp Genetics (formerly Invitae), G2P
• dyskeratosis congenita

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet
• Hoyeraal-Hreidarsson syndrome

  Inheritance: AD Classification: SUPPORTIVE Submitted by: Orphanet

ACMG classification

Our verdict: Uncertain_significance. The variant received 2 ACMG points.

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

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DKC1	NM_001363.5	c.1345C>T	p.Arg449*	stop_gained	Exon 14 of 15	ENST00000369550.10	NP_001354.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DKC1	ENST00000369550.10	c.1345C>T	p.Arg449*	stop_gained	Exon 14 of 15	1	NM_001363.5	ENSP00000358563.5

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome AF: 9.11e-7 AC: 1 AN: 1097717 Hom.: 0 Cov.: 31 AF XY: 0.00 AC XY: 0 AN XY: 363077

African (AFR) AF: 0.00 AC: 0 AN: 26394

American (AMR) AF: 0.00 AC: 0 AN: 35199

Ashkenazi Jewish (ASJ) AF: 0.00 AC: 0 AN: 19378

East Asian (EAS) AF: 0.00 AC: 0 AN: 30194

South Asian (SAS) AF: 0.00 AC: 0 AN: 54130

European-Finnish (FIN) AF: 0.00 AC: 0 AN: 40510

Middle Eastern (MID) AF: 0.00 AC: 0 AN: 4137

European-Non Finnish (NFE) AF: 0.00000119 AC: 1 AN: 841706

Other (OTH) AF: 0.00 AC: 0 AN: 46069

GnomAD4 genome Cov.: 23

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.51	D
BayesDel_noAF	Pathogenic	0.49
CADD	Pathogenic	36
DANN	Uncertain	1.0
FATHMM_MKL	Uncertain	0.94	D
PhyloP100		2.2
Vest4		0.80
GERP RS		3.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7
Mutation Taster		=22/178	disease causing (fs/PTC)

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.090		Details are displayed if max score is > 0.2

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

Other links and lift over

dbSNP: rs878853071; hg19: chrX-154004468;