HGSNAT and hyperinsulinemic hypoglycemia, familial, 4: Available records did not make any note of nonocular manifestations of mild HGSNAT deficiency, such as “coarse facial features, hypertrichosis, contractures, organomegaly, hearing impairment, behavioral and sleeping problems, recurrent infections, diarrhea, epilepsy or late onset of mental deterioration.” [44], p. 3745.