Alternating Hemiplegia and Hemiplegic Migraine

Gene: RHOBTB2

Green List (high evidence)

Eleven affected patients were identified. All had heterozygous missense variants involving exon 9 of RHOBTB2, confirmed as de novo in 9 cases. All had a complex motor phenotype, including at least 2 different kinds of movement disorder, e.g., ataxia and dystonia. Many patients demonstrated several features fulfilling the criteria for AHC: 10 patients had a movement disorder including paroxysmal elements, and 8 experienced hemiplegic episodes. In contrast to classic AHC, commonly caused by mutations in ATP1A3, these events were reported later only in RHOBTB2 mutation-positive patients from 20 months of age.

All had ID, and many had seizures, so this represents an expansion of the phenotype rather than a distinct disorder.
Sources: Literature

Created: 13 Sep 2021, 8:17 a.m.

Mode of inheritance
MONOALLELIC, autosomal or pseudoautosomal, NOT imprinted

Phenotypes
Developmental and epileptic encephalopathy 64 618004; Alternating hemiplegia

Publications

• 33504645