Overview
Babies may be floppy, feed poorly, or reach motor milestones late.
Some types stay stable over life; others slowly worsen.
Symptoms
Common signs:
- Weak, floppy baby
Less common
- Trouble feeding
Look up a symptom: Muscle weakness in arms or legs
When to get medical care
Causes
Genes.
Does it spread or run in families?
- It isn't contagious. You can't catch it from someone else.
Who is more likely to get it
- Children of a parent or with siblings who have it: Higher risk
Possible complications
- Scoliosis: From weak back muscles
- Malignant hyperthermia (reaction to anesthesia): Some types raise the risk
Diagnosis
A clinician asks about your symptoms and may order tests.
The exam
A physical exam.
Tests
Tests, if needed:
- Muscle biopsy:
- Gene test:
Treatment
Treatment depends on the cause and how severe it is.
Self-care
- Physical and occupational therapy
- Watch breathing during illness
Prevention
To lower your risk or prevent problems:
- Genetic counseling
Which doctor treats this
- Start with your primary care provider (family doctor or internist).
- They may send you to a neurologist (brain and nerve doctor).
- A physical therapist can help with exercises to rebuild strength and motion.
Living with it
Support groups and helplines
- Muscular Dystrophy Association (MDA): Care centers and support for neuromuscular diseases.
- Genetic and Rare Diseases Information Center (GARD): Free NIH information on rare diseases, including where to find experts and patient groups.
- National Organization for Rare Disorders (NORD): Patient groups, help finding care, and aid programs for rare diseases.
Children, pregnancy, and older adults
- Families: Genetic counseling helps with future pregnancies.
Pregnancy and breastfeeding
- If you're pregnant or planning to be, tell your prenatal provider about this condition.
- Don't start or stop any medicine on your own. Some are safe in pregnancy and some need to be changed.
- Ask before taking any pain reliever. The FDA advises avoiding ibuprofen and naproxen after 20 weeks unless your doctor says to.
- Breastfeeding: Most medicines are fine, but ask. The NIH LactMed database lists what's known about each one.
Outlook
Many children gain skills with therapy.
Many stay stable.
Getting ready for your visit
Bring a list of your symptoms and medicines.
What to bring
- A list of your medicines and supplements
- Notes on when symptoms started and what makes them better or worse
Questions to ask
- What's causing this?
- What treatment do you recommend?
- Which type does my child have?
Research studies
Research studies test new ways to find and treat health problems. Some are looking for volunteers. Talk with your doctor before joining one.
Search ClinicalTrials.gov for studies on Congenital myopathies
Sources
Last updated 2026-11-12.