Unknowns: Myopathies

Each of these biopsies is from a patient with a probable myopathy.
  There is variabiltiy in muscle fiber size,
  Small fibers are rounded.
  Endomysial connective tissue is increased in some.

The biopsies are stained with H & E.
What is the most likely diagnosis?
What other stains would you perform to make the diagnosis?

A 1 year old boy presents with motor delay since birth.
Examination shows joint contractures, hypotonia & diffuse weakness.
Intelligence is normal.
Serum CK is elevated at 950.
MRI shows increased T2 signal in CNS white matter.

A 20 year old male noted difficulty climbing stairs.
His mother has a history of malignant hyperthermia during surgery.
Examination shows symmetric proximal weakness.
Serum CK is 500. EMG is myopathic.

A 20 year old male is admitted to the cardiac service for repeated syncope.
His mother died suddenly several years ago.
Exam shows scapular winging, symmetric weakness, especially
  in the biceps and triceps, and elbow contractures.
Serum CK is 426. EKG shows bradycardia and atrial arrhythmias

A 5 year old male is evaluated for falling and slow running.
He was normal until 3 years of age.
Examination shows large calves, proximal weakness,
  waddling gait and difficulty arising from the floor.
Serum CK is 11,000.

A 36 year old female is evaluated for slowly progressive fatigue and weakness.
The patient's mother had similar problems.
Examination shows large calves and proximal weakness.
Serum CK is 700.

A 36 year old mentally retarded Afro-American female is evaluated for weakness and excessive sleepiness.
The patient's mother had milder weakness, but died suddenly in her 40's.
Examination shows distal > proximal weakness, especially with grip.
Serum CK is normal.

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