GTR Home > Conditions/Phenotypes > Nemaline myopathy 3

Disease characteristics

Excerpted from the GeneReview: Nemaline Myopathy
Nemaline myopathy (referred to in this entry as NM) is characterized by weakness, hypotonia, and depressed or absent deep tendon reflexes. Muscle weakness is usually most severe in the face, the neck flexors, and the proximal limb muscles. Six forms of NM exist, classified by onset and severity of motor and respiratory involvement: Severe congenital (neonatal) (16% of all individuals with NM). Amish NM. Intermediate congenital (20%). Typical congenital (46%) . Childhood-onset (13%). Adult-onset (late-onset) (4%). Considerable overlap occurs among the forms. Significant differences in survival exist between individuals classified as having severe, intermediate, and typical congenital NM. Severe neonatal respiratory disease and the presence of arthrogryposis multiplex congenita are associated with death in the first year of life. Independent ambulation before age 18 months is predictive of survival. Most children with typical congenital NM are eventually able to walk.

Associated genes

  • Also known as: RP5-1068B5.2, ACTA, ASMA, CFTD, CFTD1, CFTDM, MPFD, NEM1, NEM2, NEM3, ACTA1
    Summary: actin, alpha 1, skeletal muscle

Clinical features

  • Hyporeflexia
  • Hyperreflexia
  • Waddling gait
  • Areflexia
  • Hypertonia
  • Decreased fetal movement
  • Mask-like facies
  • Frequent falls
  • Neonatal hypotonia
  • Respiratory insufficiency due to muscle weakness
  • Bulbar palsy
  • Arthrogryposis multiplex congenita
  • Generalized muscle weakness
  • Retrognathia
  • Slender build
  • Dysphagia
  • Type 1 muscle fiber predominance
  • Spinal rigidity
  • Neck flexor weakness
  • Feeding difficulties in infancy
  • Myopathic facies
  • High palate
  • Motor delay
  • Polyhydramnios
  • Pes cavus
  • Rigidity
  • Scoliosis
  • Hyperlordosis
  • EMG: neuropathic changes
  • EMG: myopathic abnormalities
  • Limb muscle weakness
  • Proximal muscle weakness
  • Nemaline bodies
  • Late-onset distal muscle weakness
  • Mildly elevated creatine phosphokinase
Show all (35)

IMPORTANT NOTE: NIH does not independently verify information submitted to the GTR; it relies on submitters to provide information that is accurate and not misleading. NIH makes no endorsements of tests or laboratories listed in the GTR. GTR is not a substitute for medical advice. Patients and consumers with specific questions about a genetic test should contact a health care provider or a genetics professional.

Write to the Help Desk