The Management and Clinical Outcomes of Pregnancy in a Female With Glycogen Storage Disease Type IIIA Caused by Rare Variant

Glycogen storage disease type III (GSD III) is an inborn error of carbohydrate metabolism with an autosomal recessive inheritance pattern. Phenotypically, patients can manifest a broad clinical spectrum. Most patients affected with GSD IIIA (85%) have a non-functional GDE enzyme primarily affecting the liver and cardiac/skeletal muscle (Type IIIA). Initial clinical manifestations of GSD IIIA present in the first year of life. Presentation is very similar to GSD type I. Up to 98% of children affected have hepatomegaly, hypoglycaemia (53%) with marked ketosis (34%), short stature (49%), delayed puberty, and frequent infections (17%). In adulthood, they may have cirrhosis, adenomas, or hepatocarcinomas (11%), cardiomyopathy (58%) and myopathy (34%). Pregnancy has been documented in women with GSD III. Nutritional requirements are increased during pregnancy, especially in the third trimester. We report the management of a woman with GSD IIIA found to be compound heterozygous for two pathogenic AGL variants, c.798C>G p.(Tyr266Ter) and c.4258_4259ins? p.(Asp1420fs), who had a planned pregnancy. Cardiac outcomes are also described/discussed.