Jos Jansen

Chapter 1 20 Research question 3: can screening in a pre-selected liver patient group identify more patients with CDG? In chapter 2 and 3 I describe eight families we discovered based on screening of genetically unsolved CDG patients that were sent to us via the EURO-CDG network, a European collaboration. However, because of the relative mild hepatic phenotype we set out to identify additional patients. For this we screened plasma or patient-derived serum samples stored in biobanks of three different liver transplantation centers and from the hepatitis biobank in the Radboudumc. Chapter 5 describes this screening process. The results from this study were that 26% had abnormal glycosylation measured with IEF but no clear CDG profiles were detected with MS. Research question 4: can we use our cohort to gain more insight in differences between primary and secondary glycosylation defects Establishing a large cohort of patients with liver disease of various degrees left us with the unique opportunity to research glycosylation in liver disease. These data are useful as liver disease often interferes with CDG diagnostics. In chapter 5 we show that especially hyperfucosylation occurs more frequently in liver disease compared with healthy controls. As hyperfucosylation is not a known phenomenon in CDG patients this could aid in diagnostics when a CDG is suspected in a patient with severe liver disease.