GAD1 and type 1 diabetes mellitus: In another family, a novel mutation in the PTHR1 gene was found to be responsible for a form of very rare epiphyseal dysplasia, Eiken syndrome [18], that has been described only in this family [19]; one of the four Eiken patients studied had Type 1 Diabetes (T1D), with juvenile onset and the presence of GAD autoantibodies, which is likely to represent a fortuitous association.