The purpose of this study is to determine whether Growth hormon can increase strength in spinal muscular atrophy type II and III.

This pilot study is planned as a placebo-controlled cross-over trial in a limited number of patients. It is the aim to investigate the effect of GH on the short-term changes of strength and to investigate the tolerability of the treatment. If the results of the study are positive, further studies of longer duration addressing the development of motor function and quality of life could follow

Inclusion Criteria:

• genetically confirmed diagnosis of Spinal Muscular Disease
• Spinal muscular atrophy type II or III
• age between 6 years and 35 years
• ability to perform the tests for measurement of muscle strength (handheld myometry)
• informed consent of the patient and/or parents

Exclusion Criteria:

• pregnancy or lactation
• woman with child bearing potential without contraception
• overweight or BMI over 30 kg/m²
• Treatment with other drugs, that can influence strength 8 weeks before participation in the study or during participation
• medical history or evidence of a malignant or cerebral tumor
• cardiovascular, intestinal, endocrinologically or airway disease
• Hypertension
• growth hormone deficiency
• hypersensitivity to one component part of the study medication
• participation on a clinical trial during the study or 3 month before
• abuse to drugs or alcohol
• patient incapable of contracting or not able to understand the character, meaning and consequences of the clinical trial