MOGS-CDG is a multisystemic disorder, characterized by neurologic features, however, patients with isolated neurologic presentation have also been reported.
Most patients present with neurologic involvement such as early-onset developmental delay and hypotonia. Epilepsy is also common, with onset in neonatal period or early infancy. Different types of seizures have been reported including tonic, focal and tonic-clonic seizures, as well as epileptic spasms. Some of the patients present with infantile developmental and epileptic encephalopathy with burst-suppression EEG patterns. Brain MRI can show progressive cortical or subcortical atrophy, delayed myelination or thin corpus callosum. Furthermore, some patients also present with movement disorders such as dystonia or hyperkinesia.
Apart from neurological features, immunologic phenotype is also common in MOGS-CDG. For examples, several patients presented with hypogammaglobulinemia. Interestingly, some patients show decreased susceptibility to viral infections, which has been linked to shortened IgG half-life and impaired viral replication due to the MOGS defect (Sadat et al, 2014).
Other clinical presentations include facial dysmorphism such as long eyelashes, retrognathia or broad nasal tip, thoracic and limb abnormalities, osteopenia, frequent fractures, hepatomegaly, elevated transaminases, cardiorespiratory issues, feeding difficulties. One patient was reported with Hirschsprung disease.
The majority of the patients succumbs to the disease early in life, however, there have also been reports of patients surviving to early adulthood. The oldest reported patient was 19 at the time of the publication.
MOGS