Complex sentence: Due to abnormal gastrulation, the mesoderm migration is disturbed resulting in symptoms varying from minor lesions of the lower vertebrae to more severe symptoms such as complete fusion of the lower limbs.
Split into simpler sentences: Due to abnormal gastrulation, the mesoderm migration is disturbed. This disturbance results in symptoms varying from minor lesions of the lower vertebrae to more severe symptoms such as complete fusion of the lower limbs.