Also known as congenital disorder of glycosylation (CDG) type Ir (CDG1R)
An ultra-rare genetic condition that affects N-linked protein glycosylation. To date, three individuals have been reported in the medical literature.
Symptoms
In the reported patients, signs and symptoms reported include developmental delay, failure to thrive, and hypotonia. An additional reported patient presented with a milder, predominantly movement disorder phenotype, including moderate developmental delay, progressive opsoclonus, myoclonus, ataxia, tremor, and dystonia.
Diagnosis
Diagnostic testing relies on testing the appropriate glycosylation of common proteins (one commonly used glycoprotein is transferrin) This can be tested by different methods in blood. To date, all reported individuals have shown type 1 CDG pattern on carbohydrate deficient transferrin analysis. The ultimate diagnosis is genetic testing in blood, showing pathogenic variants in both copies of the DDOST gene.
Treatment and Prognosis
To date, there are no known specific treatment options for DDOST-CDG. Treatment is aimed at the management of symptoms and the prevention of complications.