PCK1 and Schnyder corneal dystrophy: Thus, increased fat mass in SCD-fed Alx3-deficient mice is consistent with increased levels of noradrenaline and enhanced expression of tyrosine hydroxylase, indicating increased sympathetic tone, as well as with enhanced expression of Pck1. Despite having a higher fat proportion under SCD, Alx3-deficient mice accumulate proportionally less fat when fed under a HFD regime.