| A rare genetic neurometabolic disorder with characteristics of severe progressive microcephaly, severe to profound global development delay, intellectual disability, seizures (typically tonic and/or myoclonic and frequently intractable), hyperekplexia and axial hypotonia with appendicular spasticity, as well as hyperreflexia, dyskinetic quadriplegia and abnormal brain morphology (cerebral atrophy with variable additional features including ventriculomegaly, pons and/or cerebellar hypoplasia, simplified gyral pattern and delayed myelination). Cortical blindness, feeding difficulties and respiratory insufficiency may also be associated. There is evidence the disease is caused by homozygous or compound heterozygous mutation in the ASNS gene on chromosome 7q21. |
