Fig. 1

MRI findings of patient 1. Top row, T2 w MRI. (B + D) Sagittal (B) and frontal (D) view of the neck muscles of patient 1 at the age of 7 years. Neck muscles and paravertebral muscles are degenerated with compensatory hyperlordosis of the cervical spine compared to (A + C) age-matched healthy controls. Second row shows the difference between right and left T2 w MRI at the age of 7 years: (E + F) frontal view of right + left shoulder showing symmetrical fatty degeneration of the supraspinatus muscle (S.m.) and involvement of the infraspinatus muscles (I.m.) compared to normal signal for deltoid muscles (D.m. in red). Bottom row shows the difference between right and left T1 w MRI at the age of 9 years: (G) Frontal view of thigh with obturator internus (O.a.m.) and adductor brevis (A.b.m) muscles replaced by fat tissue, adductor longus (A.l.m.) and adductor magnus (A.m.m.) muscles fatty degenerated. (H) A proximal axial view of the hip muscles: with the left gluteus maximus muscle (G.m.m.) showing slight signs of fatty infiltration, the right side appears not to be affected. (I + J) A distal axial view of the thigh muscle showing very slight involvement of the left biceps femoris, sartorius and semimembranosus muscles (circled in yellow) and no obvious involvement of the right thigh