Duchenne: The most common type, it affects only boys as it is anX-chromosome-linked disorder and retards growth. It results from a defect in a singleimportant protein in muscle fibres called dystrophin.
Becker: A mild variant of dmd in which the muscles of the face andinvoluntary muscles are not affected.
Limb Girdle: It affects both boys and girls and attacks the muscles ofthe upper or proximal parts of the limbs.
Facio-scapulo-humeral: This shows up the earliest and causes severeweakness in the face and shoulders. There is progressive degeneration in legs and arms.
Myotonic: The commonest observed in adults though rate of deteriorationis slow. Associated problems include cataracts, testicular atrophy, baldness anddisturbance of heart rhythm.
Spinal Muscular: Involves degeneration of the nerve cells in the spinalcord.
Charcot-Marie-Tooth disease: A group of conditions which result inweakness and wasting of muscles below the knees and often those of the hands.