Genetic Variant DDX20:p.Ala7Thr (chr1-111755943-G-A) – ACMG Classification: Likely_benign (-2 pts)

Variant summary

Our verdict is Likely benign. Variant got -2 ACMG points: 2P and 4B. PM2BP4_Strong

The NM_007204.5(DDX20):c.19G>A(p.Ala7Thr) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.0000057 in 1,578,346 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 14/21 in silico tools predict a benign outcome for this variant. No clinical diagnostic laboratories have submitted clinical-significance assessments for this variant to ClinVar. Another variant affecting the same amino acid position, but resulting in a different missense (i.e. A7S) has been classified as Uncertain significance.

Frequency

Genomes: 𝑓 0.0000066 ( 0 hom., cov: 33)

Exomes 𝑓: 0.0000056 ( 0 hom. )

Consequence

DDX20
NM_007204.5 missense

Scores

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 0.444

Variant links:

Genes affected

DDX20 (HGNC:2743): (DEAD-box helicase 20) DEAD box proteins, characterized by the conserved motif Asp-Glu-Ala-Asp (DEAD), are putative RNA helicases. They are implicated in a number of cellular processes involving alteration of RNA secondary structure such as translation initiation, nuclear and mitochondrial splicing, and ribosome and spliceosome assembly. Based on their distribution patterns, some members of this family are believed to be involved in embryogenesis, spermatogenesis, and cellular growth and division. This gene encodes a DEAD box protein, which has an ATPase activity and is a component of the survival of motor neurons (SMN) complex. This protein interacts directly with SMN, the spinal muscular atrophy gene product, and may play a catalytic role in the function of the SMN complex on RNPs. [provided by RefSeq, Jul 2008]

DDX20 links:

INKA2 (HGNC:28045): (inka box actin regulator 2) Enables protein kinase binding activity. Predicted to be involved in negative regulation of catalytic activity. Located in nucleoplasm. [provided by Alliance of Genome Resources, Apr 2022]

INKA2 links:

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ACMG classification

Classification made for transcript

Verdict is Likely_benign. Variant got -2 ACMG points.

PM2

Very rare variant in population databases, with high coverage;

BP4

Computational evidence support a benign effect (MetaRNN=0.057840914).

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DDX20	NM_007204.5 link	c.19G>A	p.Ala7Thr	missense_variant	Exon 1 of 11	ENST00000369702.5	NP_009135.4	Q9UHI6-1Q9H4N4
INKA2	NM_198926.2 link	c.-231C>T		upstream_gene_variant			NP_945120.1

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DDX20	ENST00000369702.5 link	c.19G>A	p.Ala7Thr	missense_variant	Exon 1 of 11	1	NM_007204.5	ENSP00000358716.4		Q9UHI6-1

Frequencies

GnomAD3 genomes

AF:

0.00000657

AC:

AN:

152226

Hom.:

Cov.:

show subpopulations

Gnomad AFR

AF:

0.0000241

Gnomad AMI

AF:

0.00

Gnomad AMR

AF:

0.00

Gnomad ASJ

AF:

0.00

Gnomad EAS

AF:

0.00

Gnomad SAS

AF:

0.00

Gnomad FIN

AF:

0.00

Gnomad MID

AF:

0.00

Gnomad NFE

AF:

0.00

Gnomad OTH

AF:

0.00

GnomAD3 exomes

AF:

0.0000222

AC:

AN:

224944

Hom.:

AF XY:

0.00000812

AC XY:

AN XY:

123118

show subpopulations

Gnomad AFR exome

AF:

0.00

Gnomad AMR exome

AF:

0.00

Gnomad ASJ exome

AF:

0.00

Gnomad EAS exome

AF:

0.00

Gnomad SAS exome

AF:

0.000147

Gnomad FIN exome

AF:

0.00

Gnomad NFE exome

AF:

0.00

Gnomad OTH exome

AF:

0.000189

GnomAD4 exome

AF:

0.00000561

AC:

AN:

1426120

Hom.:

Cov.:

AF XY:

0.00000284

AC XY:

AN XY:

704674

show subpopulations

Gnomad4 AFR exome

AF:

0.00

Gnomad4 AMR exome

AF:

0.00

Gnomad4 ASJ exome

AF:

0.00

Gnomad4 EAS exome

AF:

0.00

Gnomad4 SAS exome

AF:

0.0000722

Gnomad4 FIN exome

AF:

0.00

Gnomad4 NFE exome

AF:

0.00

Gnomad4 OTH exome

AF:

0.0000342

GnomAD4 genome

AF:

0.00000657

AC:

AN:

152226

Hom.:

Cov.:

AF XY:

0.0000134

AC XY:

AN XY:

74368

show subpopulations

Gnomad4 AFR

AF:

0.0000241

Gnomad4 AMR

AF:

0.00

Gnomad4 ASJ

AF:

0.00

Gnomad4 EAS

AF:

0.00

Gnomad4 SAS

AF:

0.00

Gnomad4 FIN

AF:

0.00

Gnomad4 NFE

AF:

0.00

Gnomad4 OTH

AF:

0.00

Bravo

AF:

0.00000378

ExAC

AF:

0.00000826

AC:

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name

Calibrated prediction

Score

Prediction

AlphaMissense

Benign

0.096

BayesDel_addAF

Benign

-0.34

BayesDel_noAF

Benign

-0.48

CADD

Benign

DANN

Benign

0.97

DEOGEN2

Benign

0.077

Eigen

Benign

-0.86

Eigen_PC

Benign

-0.88

FATHMM_MKL

Benign

0.047

LIST_S2

Benign

0.44

M_CAP

Benign

0.039

MetaRNN

Benign

0.058

MetaSVM

Benign

-1.1

MutationAssessor

Benign

2.0

PrimateAI

Uncertain

0.55

PROVEAN

Benign

-0.21

REVEL

Benign

0.055

Sift

Benign

0.11

Sift4G

Benign

0.063

Polyphen

0.0010

Vest4

0.18

MutPred

0.11

Gain of glycosylation at A7 (P = 0.0228);

MVP

0.55

MPC

0.076

ClinPred

0.097

GERP RS

1.6

Varity_R

0.038

gMVP

0.42

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

Below is the list of publications found by LitVar. It may be empty.

Variant summary

Frequency

Consequence

Scores

Clinical Significance

Conservation

ACMG classification

Transcripts

RefSeq

Ensembl

Frequencies

ClinVar

Computational scores

Splicing

Publications

LitVar

Other links and lift over