1999). For patients 5 and 11, a deletion was detected and confirmed by MLPA analysis (kit P309, MRC-Holland, Amsterdam, the Netherlands) (Table ​(Table2).2).

For patient 1, proteins were extracted from the muscle sample and Western blot studies were performed with R2630 and R2827 antibodies as previously described (Tosch et al. 2010). No sample was available for RNA studies, precluding the detection of any other intronic mutations. Statistical analyses A two-way analysis of variance (ANOVA) was performed to identify possible effects of population (XLMTM patients vs. controls) and of muscle (deltoid vs. vastus lateralis) on muscle fiber size, and % of satellite cells, type Inhibitors,research,lifescience,medical I fibers and central nuclei. The meta-distributions of muscle fiber size in each population were Inhibitors,research,lifescience,medical compared using the Kolmogorov–Smirnov test. The level of significance was set at 0.05. Results Clinical data The main symptoms during the pregnancy were reduced fetal movements, polyhydramnios, and oligohydramnios (Table ​(Table1).1). Common associated signs were severe hypotonia

at birth and respiratory failure requiring assisted Inhibitors,research,lifescience,medical ventilation. Facial weakness and swallowing difficulties were seen in most patients. Arthrogryposis was found in only one patient. The progression of the disease was often serious, 11 of them died before 5 months of age, three patients were still alive at 2 years and 9 months (Patient 3), at 7 years (Patient 10), and 9 months of age (Patient 11). Patient 14 had a Inhibitors,research,lifescience,medical relatively good evolution. Chronology of

the appearance of morphological features in MTM1 patients A similar morphological pattern was observed in all muscle biopsies throughout Inhibitors,research,lifescience,medical the whole period analyzed, characterized by the presence of numerous BGJ398 molecular weight hypotrophic fibers with central nuclei, compared to controls where the mean percentage of fibers with central nuclei was <1% (P < 0.0001) (Fig. ​(Fig.1,1, haematoxylin-eosin [HE]). With the oxidative staining, the fibers show a dark central region, regularly Unoprostone surrounded by a paler peripheral halo (Fig. ​(Fig.1,1, NADH-tetrazolium reductase [NADH-TR]). These small fibers belong to both type 1 and 2 (Fig. ​(Fig.2,2, ATPase). The mean percentage of fibers with central nuclei was 56.2% in vastus lateralis (range 31–84%) and 44.0% in deltoid (range 27–70%). In the scattered large type 1 fibers, corresponding to Wohlfart B fibers, centralized nuclei were never observed. Figure 1 Transverse muscle sections of Patients 6 and 15 with severe X-linked myotubular myopathy showing marked variability in fiber size and the presence of numerous hypotrophic myofibers with centrally placed nuclei (haematoxylin-eosin [HE]; pictures A and … Figure 2 Transverse muscle sections of Patients 6 and 15 with severe X-linked myotubular myopathy.