CPT2 and hyperinsulinemic hypoglycemia, familial, 4: Around 60% –70% of the patients with CPT II deficiency are homozygous for the c.338C > T mutation and remaining others are compound heterozygotes, many of which are carrying the common c.338C > T variant in combination with various rarely occurring mutations of the CPT2 gene (Isackson et al., 2006; Corti et al., 2008; Joshi et al., 2014).