• 3
    Haplo
    Score
  • 0
    Triplo
    Score

Gene Facts External Data Attribution

HGNC Symbol
DDX3X (HGNC:2745) HGNC Entrez Ensembl OMIM UCSC Uniprot GeneReviews LOVD LSDB ClinVar
HGNC Name
DEAD-box helicase 3 X-linked
Gene type
protein-coding gene
Locus type
gene with protein product
Previous symbols
DDX3
Alias symbols
DBX, HLP2, DDX14, CAP-Rf
%HI
12.73(Read more about the DECIPHER Haploinsufficiency Index)
pLI
1(Read more about gnomAD pLI score)
LOEUF
0.12(Read more about gnomAD LOEUF score)
Cytoband
Xp11.4
Genomic Coordinates
GRCh37/hg19: chrX:41192561-41223725 NCBI Ensembl UCSC
GRCh38/hg38: chrX:41333308-41364472 NCBI Ensembl UCSC
MANE Select Transcript
NM_001356.5 ENST00000644876.2 (Read more about MANE Select)
Function
Multifunctional ATP-dependent RNA helicase (PubMed:17357160, PubMed:21589879, PubMed:31575075). The ATPase activity can be stimulated by various ribo-and deoxynucleic acids indicative for a relaxed substrate specificity (PubMed:29222110). In vitro can unwind partially double-stranded DNA with a preference for 5'-single-stranded DNA overhangs (PubMed:17357160, PubMed:21589879). Binds RNA G- quadruplex (rG4s) structures, including those located in the 5'-UTR of NRAS mRNA (PubMed:30256975). Involve... (Source: Uniprot)

Dosage Sensitivity Summary (Gene)

Dosage ID:
ISCA-7993
ClinGen Curation ID:
CCID:006981
Curation Status:
Complete
Issue Type:
Dosage Curation - Gene
Haploinsufficiency:
Sufficient Evidence for Haploinsufficiency (3)
Triplosensitivity:
No Evidence for Triplosensitivity (0)
Last Evaluated:
11/22/2017

Haploinsufficiency (HI) Score Details

HI Score:
3
HI Evidence Strength:
Sufficient Evidence for Haploinsufficiency (Disclaimer)
HI Disease:
  • intellectual disability, X-linked 102 Monarch
HI Evidence:
  • PUBMED: 26235985
    Snijders et al. report 35 de novo variants in the DDX3X gene in 38 females diagnosed with ID and other features including hypotonia, movement disorders, behavior problems, corpus callosum hypoplasia, and epilepsy. A wide mutation spectrum was reported, including 5 nonsense variants and 9 frameshift variants. Variants were identified by whole exome sequencing and furthermore, a zebrafish model found a loss-of-function effect on the Wnt pathway of all tested de novo mutations. The authors also describe how in general, pathogenic DDX3X variants in females occur de novo, while males inherit DDX3X missense variants from an unaffected mother; this gender difference may be explained in part because DDX3X is known to escape X-inactivation but it is also suggested that the DDX3X gene is dosage sensitive and may have gender-specific differential activity on the Wnt pathway.
  • PUBMED: 27159028
    Fieremans et al. report 2 de novo mutations (one nonsense and one missense) detected by whole exome sequencing in a cohort of 19 females with intellectual disability and skewed X-inactivation.
  • PUBMED: 28327206
    Eldomery et al. studied unsolved clinical exome cases. De novo DDX3X mutations were detected by whole exome sequencing in 3 cases with intellectual disability (one frameshift variant and two missense variants).
HI Evidence Comments:
Haploinsufficiency of the DDX3X gene causes X-linked intellectual disability.
NOTE:

The loss-of-function and triplosensitivity ratings for genes on the X chromosome are made in the context of a male genome to account for the effects of hemizygous duplications or nullizygous deletions. In contrast, disruption of some genes on the X chromosome causes male lethality and the ratings of dosage sensitivity instead take into account the phenotype in female individuals. Factors that may affect the severity of phenotypes associated with X-linked disorders include the presence of variable copies of the X chromosome (i.e. 47,XXY or 45,X) and skewed X-inactivation in females.

Triplosensitivity (TS) Score Details

TS Score:
0
TS Evidence Strength:
No Evidence for Triplosensitivity (Disclaimer)
TS Evidence Comments:
No duplications involving only the entire HMBS gene reported
NOTE:

The loss-of-function and triplosensitivity ratings for genes on the X chromosome are made in the context of a male genome to account for the effects of hemizygous duplications or nullizygous deletions. In contrast, disruption of some genes on the X chromosome causes male lethality and the ratings of dosage sensitivity instead take into account the phenotype in female individuals. Factors that may affect the severity of phenotypes associated with X-linked disorders include the presence of variable copies of the X chromosome (i.e. 47,XXY or 45,X) and skewed X-inactivation in females.

Genomic View

Select assembly: (NC_000023.10) (NC_000023.11)