Patient case (clinical description): An 8-year-old boy is brought to the clinic by his parents because of weakness and difficulty of standing up from a sitting position. The mother is healthy but had a brother who died in his 20th after being disabled and using wheelchairs in the last few years of his life. Physical examination shows 3/5 lower extremity muscle strength and enlarged calf muscles. The other physical examination and vital signs are unremarkable. Muscle biopsy showed absence of dystrophin protein. The patient is diagnosed with DMD.

Patient's own account: I brought my  8-year-old son to the doctor's clinic. He was struggling to stand up from a chair for the past few days. My wife is healthy but she was pretty worried since his brother died in his 20s after being disabled and using a wheelchair for the last years of his life. The doctor did an exam which highlighted weakness in the leg muscles and unusually large calf muscles. The rest of the exam was fine, and his vitals were normal. My son did a muscle biopsy, and it showed that the protein important for muscle strength and function is missing. The doctor diagnosed him with Duchenne muscular dystrophy.

Clinical trial: AAV9 U7snRNA Gene Therapy to Treat Boys With DMD Exon 2 Duplications.

Eligibility criteria:
Inclusion Criteria:

          -  Age greater than 6 months and less than 14 years

          -  Confirmed duplication of exon 2 in the DMD gene using a clinically accepted technique
             that completely defines the mutation

          -  Pre-ambulant (not yet walking) or ambulant (as defined by the ability to walk 10
             meters without assistance)

          -  Males of any ethnic group will be eligible

          -  Ability to cooperate with muscle testing

          -  In subjects age 4 and above, stable dose and regimen of corticosteroid therapy
             (prednisone, deflazacort, or their generic forms) for at least 12 weeks prior to gene
             transfer.

        Exclusion Criteria:

          -  Active viral infection based on clinical observations

          -  Symptoms or signs of cardiomyopathy, including:

               1. Dyspnea on exertion, pedal edema, shortness of breath upon lying flat, or rales
                  at the base of the lungs

               2. Echocardiogram with ejection fraction below 40%

          -  Serological evidence of HIV infection, or Hepatitis B or C infection

          -  Diagnosis of (or ongoing treatment for) an autoimmune disease

          -  Persistent leukopenia or leukocytosis (WBC ≤ 3.5 K/µL or ≥ 20.0 K/µL) or an absolute
             neutrophil count < 1.5K/µL

          -  Concomitant illness or requirement for chronic drug treatment that in the opinion of
             the SI creates unnecessary risks for gene transfer

          -  AAV9 binding antibody titers ≥ 1:400 as determined by ELISA immunoassay

          -  Abnormal laboratory values in the clinically significant range as listed in Table 7,
             based upon normal values in the Nationwide Children's Hospital Laboratory.
Male
No healthy subjects accepted to join the trial.
Subject must be at least 6 Months old.
Subject must be at most 13 Years

Eligibility (NLI label): Entailment