2-171434662-C-T

Position:

• chr2-171434662-C-T

Variant summary

Our verdict is Likely pathogenic. Variant got 8 ACMG points: 8P and 0B. PVS1_Strong PM2 PP5_Moderate

The NM_025000.4(DCAF17):​c.85C>T​(p.Gln29*) variant causes a stop gained change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000145 in 1,378,120 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a pathogenic outcome for this variant. Variant has been reported in ClinVar as Pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000015 (0 hom.)
• Consequence: DCAF17 NM_025000.4 stop_gained
• Clinical Significance: Pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 3.07

Genes affected

DCAF17 (HGNC:25784): (DDB1 and CUL4 associated factor 17) This gene encodes a nuclear transmembrane protein that associates with cullin 4A/damaged DNA binding protein 1 ubiquitin ligase complex. Mutations in this gene are associated with Woodhouse-Sakati syndrome. Alternate splicing results in multiple transcript variants. [provided by RefSeq, Sep 2009]

METTL8 (HGNC:25856): (methyltransferase 8, tRNA N3-cytidine) Enables mRNA methyltransferase activity. Involved in mRNA methylation. Predicted to be located in cytoplasm and nucleus. [provided by Alliance of Genome Resources, Apr 2022]

DCAF17 (HGNC:):

ACMG classification

Verdict is Likely_pathogenic. Variant got 8 ACMG points.

• PVS1: Loss of function variant, product does not undergo nonsense mediated mRNA decay. Variant located near the start codon (<100nt), not predicted to undergo nonsense mediated mRNA decay. Fraction of 0.946 CDS is truncated, and there are 3 pathogenic variants in the truncated region.
• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 2-171434662-C-T is Pathogenic according to our data. Variant chr2-171434662-C-T is described in ClinVar as [Pathogenic]. Clinvar id is 571994.Status of the report is criteria_provided_single_submitter, 1 stars.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	Protein	UniProt
DCAF17	NM_025000.4	c.85C>T	p.Gln29*	stop_gained	1/14	ENST00000375255.8	NP_079276.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Protein	Appris	UniProt
DCAF17	ENST00000375255.8	c.85C>T	p.Gln29*	stop_gained	1/14	1	NM_025000.4	ENSP00000364404.3

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 0.00000145 AC: 2 AN: 1378120 Hom.: 0 Cov.: 31 AF XY: 0.00000147 AC XY: 1 AN XY: 681270

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.0000280

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 9.26e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ClinVar

Significance: Pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Woodhouse-Sakati syndrome Pathogenic:1

Pathogenic, criteria provided, single submitter

clinical testing

Labcorp Genetics (formerly Invitae), Labcorp

May 28, 2023

ClinVar contains an entry for this variant (Variation ID: 571994). This variant has not been reported in the literature in individuals affected with DCAF17-related conditions. The frequency data for this variant in the population databases is considered unreliable, as metrics indicate poor data quality at this position in the gnomAD database. This sequence change creates a premature translational stop signal (p.Gln29*) in the DCAF17 gene. It is expected to result in an absent or disrupted protein product. Loss-of-function variants in DCAF17 are known to be pathogenic (PMID: 19026396, 20507343). For these reasons, this variant has been classified as Pathogenic. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
BayesDel_addAF	Pathogenic	0.63	D
BayesDel_noAF	Pathogenic	0.53
CADD	Pathogenic	41
DANN	Uncertain	1.0
Eigen	Pathogenic	0.93
Eigen_PC	Pathogenic	0.82
FATHMM_MKL	Benign	0.73	D
Vest4		0.16
GERP RS		5.9
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.7

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.020		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: rs868533593; hg19: chr2-172291172;