X-154774639-T-C

Variant names:

• chrX-154774639-T-C
• rs199422253
• NM_001363.5:c.1193T>C

Variant summary

Our verdict is Likely pathogenic. The variant received 6 ACMG points: 6P and 0B. PM1 PM2 PP3_Moderate

The NM_001363.5(DKC1):​c.1193T>C​(p.Leu398Pro) 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. 12/21 in silico tools predict a damaging outcome for this variant. Variant has been reported in ClinVar as not provided (no stars). Synonymous variant affecting the same amino acid position (i.e. L398L) has been classified as Likely benign.

• Frequency: Genomes: not found (cov: 23)
• Consequence: DKC1 NM_001363.5 missense
• Clinical Significance: not provided no classification provided O:1
• Conservation: PhyloP100: 7.60
• Publications: 6 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: Likely_pathogenic. The variant received 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
• PP3: MetaRNN computational evidence supports a deleterious effect, 0.915

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DKC1	NM_001363.5	c.1193T>C	p.Leu398Pro	missense_variant	Exon 12 of 15	ENST00000369550.10	NP_001354.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DKC1	ENST00000369550.10	c.1193T>C	p.Leu398Pro	missense_variant	Exon 12 of 15	1	NM_001363.5	ENSP00000358563.5

Frequencies

GnomAD3 genomes Cov.: 23

GnomAD4 exome Cov.: 30

GnomAD4 genome Cov.: 23

Alfa AF: 0.000133 Hom.: 1

ClinVar

Significance: not provided

Submissions summary: Other:1

Revision: no classification provided

Submissions by phenotype

Dyskeratosis congenita, X-linked Other:1

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GeneReviews

Significance: not provided

Review Status: no classification provided

Collection Method: literature only

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Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	1.0
BayesDel_addAF	Pathogenic	0.70	D
BayesDel_noAF	Pathogenic	0.77
CADD	Pathogenic	26
DANN	Pathogenic	1.0
DEOGEN2	Pathogenic	0.87	.;D
FATHMM_MKL	Pathogenic	0.99	D
LIST_S2	Pathogenic	0.99	D;D
M_CAP	Pathogenic	0.96	D
MetaRNN	Pathogenic	0.92	D;D
MetaSVM	Pathogenic	1.1	D
MutationAssessor	Pathogenic	3.2	M;M
PhyloP100		7.6
PrimateAI	Uncertain	0.72	T
PROVEAN	Pathogenic	-6.0	.;D
REVEL	Pathogenic	0.94
Sift	Pathogenic	0.0	.;D
Sift4G	Pathogenic	0.0	D;D
Polyphen		1.0	.;D
Vest4		0.86
MutPred		0.50		Gain of loop (P = 0.0166);Gain of loop (P = 0.0166);
MVP		1.0
MPC		3.3
ClinPred		1.0	D
GERP RS		5.5
RBP_binding_hub_radar		1.1
RBP_regulation_power_radar		2.8
Varity_R		0.96
gMVP		1.0
Mutation Taster		=0/100	disease causing (ClinVar)

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

Other links and lift over

dbSNP: rs199422253; hg19: chrX-154002914;