Figure 2. Pattern of muscle MRI associated to POGLUT1 mutations.

The muscle MRI images display a pattern of muscle fatty infiltration showing the internal parts of the muscles more severely degenerated compared to the external areas, especially in the thigh muscles (for example, asterisks in the vastus lateralis, semimembranosus, semitendinosus and biceps femoris muscles of patient II.1, Family 7), making up what we called an “inside-to outside” pattern. This pattern progressively disappears during the disease progression, but it was still recognizable in the vastus lateralis muscle when the rest of the thigh muscles had reached the end stage (arrows). The lower leg muscles were better preserved even when the thigh muscles showed an advanced degeneration (arrowheads). For each patient, the upper row is thigh and the lower row is lower leg.