12-48832465-G-A

Variant names:

• chr12-48832465-G-A
• NM_004818.3:c.1912C>T

Variant summary

Our verdict is Uncertain significance. Variant got 3 ACMG points: 4P and 1B. PM2 PP5_Moderate BP4

The NM_004818.3(DDX23):​c.1912C>T​(p.Arg638Cys) 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 1,461,882 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. Variant has been reported in ClinVar as Likely pathogenic (★).

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 6.8e-7 (0 hom.)
• Consequence: DDX23 NM_004818.3 missense
• Clinical Significance: Likely pathogenic criteria provided, single submitter P:1
• Conservation: PhyloP100: 3.15

Genes affected

DDX23 (HGNC:17347): (DEAD-box helicase 23) This gene encodes a member of the DEAD box protein family. 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. The protein encoded by this gene is a component of the U5 snRNP complex; it may facilitate conformational changes in the spliceosome during nuclear pre-mRNA splicing. An alternatively spliced transcript variant has been found for this gene, but its biological validity has not been determined. [provided by RefSeq, Jul 2008]

ACMG classification

Verdict is Uncertain_significance. Variant got 3 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• PP5: Variant 12-48832465-G-A is Pathogenic according to our data. Variant chr12-48832465-G-A is described in ClinVar as [Likely_pathogenic]. Clinvar id is 1699432.Status of the report is criteria_provided_single_submitter, 1 stars.
• BP4: Computational evidence support a benign effect (MetaRNN=0.3008346). . Strength limited to SUPPORTING due to the PP5.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	MANE	Protein	UniProt
DDX23	NM_004818.3	c.1912C>T	p.Arg638Cys	missense_variant	Exon 14 of 17	ENST00000308025.8	NP_004809.2

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	Exon rank	TSL	MANE	Protein	Appris	UniProt
DDX23	ENST00000308025.8	c.1912C>T	p.Arg638Cys	missense_variant	Exon 14 of 17	1	NM_004818.3	ENSP00000310723.2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD4 exome AF: 6.84e-7 AC: 1 AN: 1461882 Hom.: 0 Cov.: 31 AF XY: 0.00000138 AC XY: 1 AN XY: 727244

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: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 8.99e-7

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

EpiCase AF: 0.0000545

EpiControl AF: 0.00

ClinVar

Significance: Likely pathogenic

Submissions summary: Pathogenic:1

Revision: criteria provided, single submitter

Submissions by phenotype

Neurodevelopmental disorder Pathogenic:1

Sep 02, 2022

Victorian Clinical Genetics Services, Murdoch Childrens Research Institute

Significance: Likely pathogenic

Review Status: criteria provided, single submitter

Collection Method: clinical testing

Based on the classification scheme VCGS_Germline_v1.3.4, this variant is classified as Likely Pathogenic. Following criteria are met: 0105 - The mechanism of disease for this gene is not clearly established. However, dominant negative or gain of function, rather than loss of function, appears to be the most likely mechanism (PMID:34050707). (I) 0107 - This gene is associated with autosomal dominant disease. (I) 0200 - Variant is predicted to result in a missense amino acid change from arginine to cysteine. (I) 0251 - This variant is heterozygous. (I) 0301 - Variant is absent from gnomAD (both v2 and v3). (SP) 0501 - Missense variant consistently predicted to be damaging by multiple in silico tools or highly conserved with a major amino acid change. (SP) 0603 - Missense variant in a region that is highly intolerant to missense variation (high constraint region in DECIPHER). This variant is also located in the annotated RecA-like domain where other pathogenic missense variants have been reported (PMID:34050707). (SP) 0705 - No comparable missense variants have previous evidence for pathogenicity. (I) 0807 - This variant has no previous evidence of pathogenicity. (I) 0905 - No published segregation evidence has been identified for this variant. (I) 1007 - No published functional evidence has been identified for this variant. (I) 1203 - This variant has been shown to be de novo in the proband (parental status confirmed by trio analysis). (SP) Legend: (SP) - Supporting pathogenic, (I) - Information, (SB) - Supporting benign -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Pathogenic	0.86
BayesDel_addAF	Benign	-0.061	T
BayesDel_noAF	Benign	-0.33
CADD	Pathogenic	29
DANN	Uncertain	1.0
DEOGEN2	Benign	0.33	T
Eigen	Uncertain	0.32
Eigen_PC	Uncertain	0.43
FATHMM_MKL	Uncertain	0.95	D
LIST_S2	Uncertain	0.93	D
M_CAP	Benign	0.084	D
MetaRNN	Benign	0.30	T
MetaSVM	Benign	-1.1	T
MutationAssessor	Pathogenic	3.5	M
PrimateAI	Pathogenic	0.87	D
PROVEAN	Pathogenic	-6.5	D
REVEL	Benign	0.24
Sift	Uncertain	0.025	D
Sift4G	Benign	0.062	T
Polyphen		0.22	B
Vest4		0.42
MutPred		0.42		Loss of disorder (P = 0.0218);
MVP		0.47
MPC		1.8
ClinPred		0.96	D
GERP RS		5.2
RBP_binding_hub_radar		0.0
RBP_regulation_power_radar		1.2
Varity_R		0.67
gMVP		0.88

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.010		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

No publications associated with this variant yet.

Other links and lift over

hg19: chr12-49226248;