Genetic Epilepsy

Gene: DDX3X

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. Seizures are a feature.

Created: 8 Nov 2021, 9:12 a.m. | Last Modified: 9 Mar 2024, 1:27 a.m.

Panel Version: 0.2352

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

• 30266093
• 26235985
• 25533962
• 33528536
• 30936465
• 31274575
• 30817323