What Is Duchenne Muscular Dystrophy (DMD)?

DMD is a progressive disorder of muscle weakness, which means muscles get weaker over time

DMD is estimated to occur in up to 1 in 3500 live male births in the United States and is the most common form of muscular dystrophy in children

DMD is caused by a mutation in the gene responsible for producing a protein called dystrophin

How Does DMD Cause Muscle Weakness?

  • People living with DMD do not have enough dystrophin protein
  • Dystrophin is necessary to strengthen and stabilize muscles to prevent damage during muscle contraction
  • In people living with DMD, muscle damage also causes chronic inflammation, where inflammatory cells remain active in damaged muscles, causing even more muscle damage and muscle weakness over time 
1
People living with DMD do not have enough dystrophin protein
2
Without dystrophin, muscle contraction causes muscle damage and muscle weakness
3
Inflammation causes even more muscle damage and muscle weakness over time

What Are the Symptoms of DMD?

All children living with DMD have muscle damage and muscle weakness that is progressive (gets worse over time)

Initially, DMD impacts the muscles that control bones in hips and legs 

This can impact the ability to get around, play, and participate in normal activities 

DMD increases the risk for osteoporosis (weakening of bones) and fractures 

Bone fractures can impact mobility, which can also contribute to the worsening muscle weakness over time

Over time, weakness can advance to other muscles 

Muscles of the heart and diaphragm (important for controlling breathing) are eventually affected

Behavior and learning problems may also occur 

The lack of healthy dystrophin in the brain may result in social, behavioral, and emotional problems, as well as cognitive and learning impairments

Role of Corticosteroids in DMD Treatment

Corticosteroids slow disease progression by reducing inflammation and maintaining muscle strength and control

However, corticosteroids also have unwanted side effects that can limit their use in treatment.

  • These side effects may include behavior changes growth delay, bone changes or fractures, cushingoid appearance (facial puffiness), weight gain, excessive hair growth, and cataracts 
  • Many of these side effects may make it necessary to modify or stop corticosteroid therapy
    • >6 of 10 people with DMD who stop treatment with corticosteroids do so because of side effects 

Talk with your healthcare provider about any side effects experienced while taking corticosteroids

About
AGAMREE®

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Introduction
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Watch an introductory video about AGAMREE, a novel corticosteroid for the treatment of DMD

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