Up to date, 110 separate mutations have been identified in the SLC37A4 gene of GSD-Ib and non-GSD-Ia studied patients, including 61 missense/nonsense 1 regulatory and 17 splicing mutations, 29 small insertion/deletions, and 2 gross deletions (http://www.hgmd.cf.ac.uk/ac/gene.php?gene=SLC37A4). Here, SLC37A4 is linked to glycogen storage disease Ib.