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Updated: Sep 9, 2025

In Vivo Functional Study of Disease-associated Rare Human Variants Using Drosophila
Published on: August 20, 2019
Infant Born With Autosomal Recessive Glycogen Storage Disease Type IV due to Complete Maternal Isodisomy of
Sigrid Skovby Olsen1, Anja Ernst2, Pia Sønderby Christensen3
1Department of Clinical Genetics, Aalborg University Hospital, Aalborg, Denmark.
Abstract:
Uniparental disomy (UPD), the inheritance of two copies of a chromosome from one parent, can lead to recessive genetic disorders or imprinting effects. We report a case of autosomal recessive glycogen storage disease type 4 (GSD IV) due to maternal UPD of chromosome 3, representing the first reported instance of UPD leading to this rare disorder. To avoid an unjustified claim of misattributed paternity, the possibility of UPD should always be kept in mind in cases with the unique finding of the homozygous pathogenic variant only present in one parent. This case highlights the critical role of genetic counseling in uncovering rare genetic conditions and emphasizes the need for continued awareness of UPD in clinical genetics.
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