ALG11-CDG: Three novel mutations and further characterization of the phenotype.

We report on two novel patients with ALG11-CDG. The phenotype was characterized by severe psychomotor disability, progressive microcephaly, sensorineural hearing loss, therapy-resistant epilepsy with burst suppression EEG, cerebral atrophy with, in one of them, neuronal heterotopia, and early lethality. Analysis of ALG11 revealed compound heterozygosity involving three novel mutations: the splice site mutation c.45-2A > T, the c.36dupG duplication, and the missense mutation c.479G > T (p.G160V) that was present in both.