A missense mutation at 17β-HSD10 results in infantile neurodegeneration 17β-HSD10 deficiency [36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57], for which Aβ peptide levels were undetectable or barely detectable in CSF [71]. Here, FSIP1 is linked to hyperinsulinemic hypoglycemia, familial, 4.