X-154776194-G-C

Variant names:

• chrX-154776194-G-C
• rs1289430524
• NM_001363.5:c.1346G>C

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 3P and 0B. PM2 PP2

The NM_001363.5(DKC1):​c.1346G>C​(p.Arg449Pro) variant causes a missense change. The variant was absent in control chromosomes in GnomAD project. Variant has been reported in ClinVar as Uncertain significance (★).

• Frequency: Genomes: not found (cov: 23)
• Consequence: DKC1 NM_001363.5 missense
• Clinical Significance: Uncertain significance criteria provided, single submitter U:1
• Conservation: PhyloP100: 5.90

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 Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP2: Missense variant in the DKC1 gene, where missense mutations are typically associated with disease (based on misZ statistic). The gene has 22 curated pathogenic missense variants (we use a threshold of 10). The gene has 27 curated benign missense variants. Gene score misZ: 3.3994 (above the threshold of 3.09). GenCC associations: The gene is linked to Hoyeraal-Hreidarsson syndrome, DKC1-related disorder, dyskeratosis congenita, X-linked, dyskeratosis congenita.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DKC1	NM_001363.5	c.1346G>C	p.Arg449Pro	missense_variant	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.1346G>C	p.Arg449Pro	missense_variant	Exon 14 of 15	1	NM_001363.5	ENSP00000358563.5

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 31

GnomAD4 genome Cov.: 23

ClinVar

Significance: Uncertain significance

Submissions summary: Uncertain:1

Revision: criteria provided, single submitter

Submissions by phenotype

Dyskeratosis congenita Uncertain:1

Jul 30, 2017

Labcorp Genetics (formerly Invitae), Labcorp

Significance: Uncertain significance

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Algorithms developed to predict the effect of missense changes on protein structure and function do not agree on the potential impact of this missense change (SIFT: "Deleterious"; PolyPhen-2: "Benign"; Align-GVGD: "Class C0"). This sequence change replaces arginine with proline at codon 449 of the DKC1 protein (p.Arg449Pro). The arginine residue is weakly conserved and there is a moderate physicochemical difference between arginine and proline. This variant is not present in population databases (ExAC no frequency). This variant has not been reported in the literature in individuals with DKC1-related disease. 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	Uncertain	0.54
BayesDel_addAF	Pathogenic	0.38	D
BayesDel_noAF	Pathogenic	0.31
CADD	Pathogenic	27
DANN	Uncertain	1.0
DEOGEN2	Benign	0.36	T
FATHMM_MKL	Pathogenic	0.98	D
LIST_S2	Benign	0.79	T
M_CAP	Pathogenic	0.74	D
MetaRNN	Uncertain	0.71	D
MetaSVM	Pathogenic	0.88	D
MutationAssessor	Uncertain	2.6	M
PrimateAI	Uncertain	0.54	T
PROVEAN	Benign	-1.6	N
REVEL	Uncertain	0.49
Sift	Benign	0.048	D
Sift4G	Benign	0.078	T
Polyphen		1.0	D
Vest4		0.46
MutPred		0.25		Gain of loop (P = 0.0121);
MVP		0.94
MPC		0.56
ClinPred		0.94	D
GERP RS		5.0
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.1
Varity_R		0.50
gMVP		0.31

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.030		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: rs1289430524; hg19: chrX-154004469;