GTR Home > Conditions/Phenotypes > Bethlem myopathy

Disease characteristics

Excerpted from the GeneReview: Congenital Muscular Dystrophy Overview
Congenital muscular dystrophy (CMD) is a clinically and genetically heterogeneous group of inherited muscle disorders. Muscle weakness typically presents from birth to early infancy. Affected infants typically appear "floppy" with low muscle tone and poor spontaneous movements. Affected children may present with delay or arrest of gross motor development together with joint and/or spinal rigidity. Muscle weakness may improve, worsen, or stabilize in the short term; however, with time progressive weakness and joint contractures, spinal deformities, and respiratory compromise may affect quality of life and life span. The main CMD subtypes, grouped by involved protein function and gene in which causative mutations occur, are laminin alpha-2 (merosin) deficiency (MDC1A), collagen VI-deficient CMD, the dystroglycanopathies (caused by mutations in POMT1, POMT2, FKTN, FKRP, LARGE, POMGNT1, and ISPD), SEPN1-related CMD (previously known as rigid spine syndrome, RSMD1) and LMNA-related CMD (L-CMD). Several less known CMD subtypes have been reported in a limited number of individuals. Cognitive impairment ranging from intellectual disability to mild cognitive delay, structural brain and/or eye abnormalities, and seizures are found almost exclusively in the dystroglycanopathies while white matter abnormalities without major cognitive involvement tend to be seen in the laminin alpha-2-deficient subtype.

Available tests

32 tests are in the database for this condition. Compare labs offering these tests.

Check Associated genes and Related conditions for additional relevant tests.

Associated genes

Clinical features

  • Decreased fetal movement
  • Distal muscle weakness
  • EMG abnormality
  • Neonatal hypotonia
  • Respiratory insufficiency due to muscle weakness
  • Ankle contracture
  • Torticollis
  • Motor delay
  • Limitation of joint mobility
  • Abnormality of the cardiovascular system
  • Elbow flexion contracture
  • Myopathy
  • Elevated serum creatine phosphokinase
  • Limb-girdle muscle weakness
  • Proximal muscle weakness
  • Decreased body weight
  • Congenital muscular torticollis
  • Camptodactyly of finger
Show all (18)

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