Both our nutritional assessment [53] on symptomless citrin deficiency subjects from 1 year old and 36 years old, and Nakamura et al. on CTLN2 patients [54] revealed reduced intake of carbohydrates, which is very important as a pathogenesis of citrin deficiency and for the treatment of citrin deficiency, as stated later. The gene discussed is SLC25A13; the disease is citrin deficiency.