We developed a novel somite-based step-wise strategy for the efficient derivation of functional human myocytes, suggesting that past failures were due to incomplete specification. Treatment with two small molecules inhibiting glycogen synthase kinase 3β (GSK-3β) and the Notch signaling pathway in undifferentiated hPSCs results in the formation of somite-like cells by Day 4 and, subsequently contractile myotubes in vitro around Day 25 with the ability to engraft and actively participate in muscle repair in vivo. Antibody-based purification can enrich homogenous myocyte populations exhibiting genuine myogenic molecular and cellular characteristics, including extraocular muscle-like features. Furthermore, hPSCs derived from patients with multiple neuromuscular diseases successfully give rise to patient-specific skeletal muscle cells bearing signature phenotypes. Human embryonic stem cell were differentiated to skeletal muscle and compared to non-differentiated cells in triplicate biological replicates. For the confirmation of differentiated cell's characteristics and the global mRNA profiles, We used microarrays to detail the global programme of gene expression underlying cellularisation and identified distinct classes of up-regulated genes during this process. Further more, we used microarrys for the comparing control and disease gene expression profiles, again in triplicate.