| Main clinical features
|
severe multisystem and neurologic phenotype resulting in early death
severe hypotonia, myopathic facies, and dysmorphic features, severe congenital contractures of the joints and scoliosis; early onset of severe focal, generalized, or myoclonic seizures
profoundly delayed psychomotor development without visual tracking, head control, or speech,microcephaly, and brain MRI in any cases showed cerebellar hypoplasia, or loss of periventricular and subcortical white matter
increased serum transaminases and creatine kinase, and decreased antithrombin activity; serum transferrin showed abnormal N-glycosylation, consistent with CDG type I |