Congenital Muscular Dystrophy (CMD)

Signs and Symptoms

Congenital muscular dystrophy (CMD) refers to a group of muscle disorders in which symptoms begin at birth or in early infancy (typically before age 2).

The most common early sign is hypotonia, or low muscle tone, which can make an infant appear “floppy.” As children grow, they often have muscle weakness that can be mild or more severe, depending on the type of CMD.

As a result of this weakness and hypotonia, babies and young children may:

• Be slow to reach motor milestones such as rolling, sitting, or walking
• Have difficulty with movement or may not achieve some milestones

Many children with CMD also develop contractures (tightness of muscles/joints), especially in the ankles, knees, hips, or wrists, which can limit movement over time.

The severity and progression of CMD vary widely. Some forms progress slowly, while others may lead to more significant muscle weakness earlier in life.

Depending on the specific type of CMD, other symptoms may include:

• Breathing or respiratory difficulties
• Feeding or swallowing challenges
• Spine curvature (scoliosis)
• In some subtypes, brain involvement that can affect learning or development, or result in seizures

Since CMD includes many different subtypes, each with its own pattern of symptoms, the experience can vary from person to person.

For more on the specific symptoms of different types of CMD, see Types of CMD.

Additional reading

• Pasrija D, Tadi P. Congenital Muscular Dystrophy. [Updated 2023 Jul 3]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK558956/
• Bönnemann CG, Wang CH, Quijano-Roy S, Deconinck N, Bertini E, Ferreiro A, Muntoni F, Sewry C, Béroud C, Mathews KD, Moore SA, Bellini J, Rutkowski A, North KN; Members of International Standard of Care Committee for Congenital Muscular Dystrophies. Diagnostic approach to the congenital muscular dystrophies. Neuromuscul Disord. 2014 Apr;24(4):289-311. doi: 10.1016/j.nmd.2013.12.011. Epub 2014 Jan 9. PMID: 24581957; PMCID: PMC5258110.

Last reviewed June 2026.