Intellectual disability syndromic and non-syndromic
Gene: DDX3X

DDX3X (DEAD-box helicase 3, X-linked)
EnsemblGeneIds (GRCh38): ENSG00000215301
EnsemblGeneIds (GRCh37): ENSG00000215301
OMIM: 300160, Gene2Phenotype
DDX3X is in 10 panels

2 reviews

Abhijit Kulkarni (Monash Genetics)

Genotype-Phenotype Correlations

Females. Affected females with a subset of missense variants generally are more severely affected than those with truncating variants PMID: 32135084

Polymicrogyria has been associated with missense or in-frame deletions PMID: 32135084

Males. While all affected males have had missense DDX3X variants , their female relatives who are heterozygous for the same DDX3X variant do not manifest an atypical neurodevelopmental phenotype.
Created: 21 Feb 2024, 1:44 a.m. | Last Modified: 21 Feb 2024, 1:45 a.m.

Panel Version: 0.5699

Publications

PMID: 32135084
32852922

Created: 21 Feb 2024, 1:44 a.m.
Last Modified: 21 Feb 2024, 1:45 a.m.
Panel version: 0.5699

Zornitza Stark (Victorian Clinical Genetics Services; Australian Genomics)

Green List (high evidence)

Syndromic X-linked mental retardation of the Snijders Blok type (MRXSSB), which occurs predominantly in females, is characterised by mildly to severely impaired intellectual development with variable other features including brain abnormalities, microcephaly, hypotonia, movement disorder and/or spasticity, ventricular enlargement, hypoplasia, and behavioural problems. Affected girls have de novo heterozygous mutations consistent with X-linked dominant inheritance. No consistent dysmorphic facial phenotype and onset in infancy. Multiple unrelated families reported.
Created: 8 Nov 2021, 9:14 a.m. | Last Modified: 8 Nov 2021, 9:14 a.m.

Panel Version: 0.4259

Mode of inheritance
X-LINKED: hemizygous mutation in males, monoallelic mutations in females may cause disease (may be less severe, later onset than males)

Phenotypes
Intellectual developmental disorder, X-linked, syndrome, Snijders Blok type MIM# 300958

Publications

Created: 8 Nov 2021, 9:14 a.m.
Last Modified: 8 Nov 2021, 9:14 a.m.
Panel version: 0.4259

Details

Mode of Inheritance

X-LINKED: hemizygous mutation in males, monoallelic mutations in females may cause disease (may be less severe, later onset than males)

Sources

Expert Review Green
Genetic Health Queensland

Phenotypes

Intellectual developmental disorder, X-linked, syndrome, Snijders Blok type MIM# 300958

OMIM

300160

Clinvar variants

Variants in DDX3X

Penetrance

None

Publications

Panels with this gene