BECN1 and hyperinsulinemic hypoglycemia, familial, 4: Moreover, Beclin 1 appears to be critically involved in the impairment of the autophagic flux in muscular diseases associated with collagen VI deficiency, as demonstrated by the markedly decreased Beclin 1 protein levels in muscles from fasted Col6a1–/– mice and in muscle biopsies from Bethlem/Ullrich patients [17].