Is there a congenital disorder of glycosylation-like process in PWS?
Several weeks ago I received an e-mail from a mother with a 4-year-old son who was initially diagnosed with a congenital disorder of glycosylation (CDG) based on a finding of elevated asialotransferrin. Shortly thereafter the genetic diagnosis of PWS/UPD was made and the CDG diagnosis was dropped with the parents being told the elevated asialotransferrin was a “red herring” that probably didn’t mean much although it could be something that hadn’t been noticed before in PWS. That of course was a clear indication that CDGs needed to be looked into. CDGs are the result of defects in what’s known as glycosylation in which carbohydrate chains consisting of combinations of mannose, glucose, galactose, and other sugars are attached to proteins. Among other things, the carb chains help the protein fold properly so it can act as an enzyme, signaling molecule or receptor. There are two broad types of CDGs. Type I CDGs are the result of defects in the assembly and transfer of the carb chains to t
