Biallelic mutations in the RNU12 gene cause a multisystem disorder with several presentations, depending on the variant involved. Known presentations include:
Early onset cerebellar ataxia (EOCA):
Congenital hypotonia
Delayed motor milestones
Mild to moderate cognitive impairment
Seizures (febrile or complex partial)
Dysarthric speech
Nystagmus
Strabismus
Truncal ataxia and intention tremor
Wide based gait, falls on turning
MRI: reduced cerebellar vermis and cerebellar hemisphere volumes, with or without thinning of corpus callosum, reduced pontine volume
CDAGS:
Craniosynostosis
Delayed closure of the fontanelles
Cranial defects
Clavicular hypoplasia
Anal and Genitourinary malformations
Skin manifestations
RNU12