Fig.2. Mutations in the MTTP gene .

At least 74 MTTP mutations have been reported. The type of mutation may influence the severity of the disease ²⁹⁾ . The exon-intron structure of the MTTP gene encoded by exons 1a to 18 has been described ⁵²⁾ . Gray boxes represent exons. Lines represent the position of each mutation and polymorphism. Adapted from Zamel R, et al. ⁴¹⁾ , Narcisi TM et al. ²⁷⁾ , and Suzuki T et al. ⁵²⁾