1-111756720-C-T

Variant summary

Our verdict is Uncertain significance. The variant received 1 ACMG points: 2P and 1B. PM2BP4

The NM_007204.5(DDX20):​c.376C>T​(p.Leu126Phe) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.000000684 in 1,461,804 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts 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. L126V) has been classified as Uncertain significance.

Frequency

Genomes: not found (cov: 32)
Exomes 𝑓: 6.8e-7 ( 0 hom. )

Consequence

DDX20
NM_007204.5 missense

Scores

8
11

Clinical Significance

Not reported in ClinVar

Conservation

PhyloP100: 1.89

Publications

1 publications found
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]

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ACMG classification

Classification was made for transcript

Our verdict: Uncertain_significance. The variant received 1 ACMG points.

PM2
Very rare variant in population databases, with high coverage;
BP4
Computational evidence support a benign effect (MetaRNN=0.40879706).

Transcripts

RefSeq

Gene Transcript HGVSc HGVSp Effect Exon rank MANE Protein UniProt
DDX20NM_007204.5 linkc.376C>T p.Leu126Phe missense_variant Exon 2 of 11 ENST00000369702.5 NP_009135.4 Q9UHI6-1Q9H4N4

Ensembl

Gene Transcript HGVSc HGVSp Effect Exon rank TSL MANE Protein Appris UniProt
DDX20ENST00000369702.5 linkc.376C>T p.Leu126Phe missense_variant Exon 2 of 11 1 NM_007204.5 ENSP00000358716.4 Q9UHI6-1

Frequencies

GnomAD3 genomes
Cov.:
32
GnomAD4 exome
AF:
6.84e-7
AC:
1
AN:
1461804
Hom.:
0
Cov.:
30
AF XY:
0.00
AC XY:
0
AN XY:
727204
show subpopulations
⚠️ The allele balance in gnomAD version 4 Exomes is significantly skewed from the expected value of 0.5.
African (AFR)
AF:
0.00
AC:
0
AN:
33480
American (AMR)
AF:
0.00
AC:
0
AN:
44722
Ashkenazi Jewish (ASJ)
AF:
0.00
AC:
0
AN:
26132
East Asian (EAS)
AF:
0.00
AC:
0
AN:
39692
South Asian (SAS)
AF:
0.00
AC:
0
AN:
86246
European-Finnish (FIN)
AF:
0.00
AC:
0
AN:
53416
Middle Eastern (MID)
AF:
0.00
AC:
0
AN:
5768
European-Non Finnish (NFE)
AF:
8.99e-7
AC:
1
AN:
1111956
Other (OTH)
AF:
0.00
AC:
0
AN:
60392
⚠️ The allele balance in gnomAD4 Exomes is highly skewed from 0.5 (p-value = 0.000000), which strongly suggests a high chance of mosaicism in these individuals.
Allele Balance Distribution
Red line indicates average allele balance
Average allele balance: 0.375
Heterozygous variant carriers
0
0
1
1
2
2
0.00
0.20
0.40
0.60
0.80
0.95
Allele balance

Age Distribution

Exome Het
Variant carriers
0
2
4
6
8
10
<30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
>80
Age
GnomAD4 genome
Cov.:
32
Alfa
AF:
0.00
Hom.:
0
Bravo
AF:
0.00000378

ClinVar

Not reported in ClinVar

Computational scores

Source: dbNSFP v4.3

Name
Calibrated prediction
Score
Prediction
AlphaMissense
Benign
0.26
BayesDel_addAF
Benign
-0.19
T
BayesDel_noAF
Benign
-0.50
CADD
Pathogenic
27
DANN
Uncertain
1.0
DEOGEN2
Benign
0.19
T
Eigen
Uncertain
0.41
Eigen_PC
Uncertain
0.41
FATHMM_MKL
Uncertain
0.79
D
LIST_S2
Benign
0.83
T
M_CAP
Benign
0.019
T
MetaRNN
Benign
0.41
T
MetaSVM
Benign
-1.0
T
MutationAssessor
Benign
1.4
L
PhyloP100
1.9
PrimateAI
Uncertain
0.62
T
PROVEAN
Uncertain
-2.6
D
REVEL
Benign
0.13
Sift
Uncertain
0.028
D
Sift4G
Uncertain
0.028
D
Polyphen
1.0
D
Vest4
0.44
MutPred
0.32
Gain of loop (P = 0.2754);
MVP
0.71
MPC
0.33
ClinPred
0.98
D
GERP RS
4.7
Varity_R
0.36
gMVP
0.50
Mutation Taster
=55/45
polymorphism

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

Other links and lift over

dbSNP: rs767839185; hg19: chr1-112299342; COSMIC: COSV100865874; COSMIC: COSV100865874; API