Complex sentence: Other associated skin conditions are very common in Werner syndrome patients, including ulcers, which are extremely common and difficult to treat in Werner syndrome patients, and are caused in part by decreased potential of skin cells for replication.
Split into simpler sentences: Other associated skin conditions are very common in Werner syndrome patients, including ulcurs. Ulcers are extremely common and difficult to treat in Werner syndrome patients, and are caused in part by decreased potential of skin cells for replication.