Skip to content
Use your HSA or FSA funds

Condition report · Musculoskeletal

Congenital Myopathy

Inherited muscle disorders, usually present from birth or early childhood, that cause muscle weakness and low muscle tone. Some forms, particularly those caused by RYR1 variants, also increase the risk of malignant hyperthermia during anesthesia.

A condition report looks for rare variants known to cause the conditions it covers.

Included in Premium and Premium + AI

Premium adds $99 per kit for the first year.

Order with Premium

The 7 conditions we analyse

RYR1-related myopathy

Muscle disorders caused by RYR1 variants, including central core and multi-minicore disease, ranging from mild weakness to severe congenital myopathy.

What a diagnosis changes

People with RYR1 variants may be at risk of malignant hyperthermia, so their anesthetist should be told before any surgery.

Genes analysed

Also known as

neurological muscular channelopathy due to a genetic ryanodine receptor defect; RYR1-related disease; RYR1-related disorder

Includes 5 related subtypes ↓
  • central core myopathy
  • congenital multicore myopathy with external ophthalmoplegia
  • congenital myopathy with myasthenic-like onset
  • King-Denborough syndrome
  • rhabdomyolysis-myalgia syndrome
MONDO:0100150Orphanet 98742

Nemaline myopathy

A congenital myopathy defined by rod-shaped structures in muscle fibers, most often caused by NEB or ACTA1 variants.

Genes analysed

Also known as

congenital rod disease; NEM; nemaline body disease; nemaline rod disease; nemaline rod myopathy; NM; Rod body disease; rod myopathy; Rod-body myopathy

Includes 18 related subtypes ↓
  • adult-onset nemaline myopathy
  • childhood-onset nemaline myopathy
  • congenital myopathy 23
  • congenital myopathy 2a, typical, autosomal dominant
  • congenital myopathy 4A, autosomal dominant
  • congenital myopathy 4B, autosomal recessive
  • MYPN-related myopathy
  • nemaline myopathy 10
  • nemaline myopathy 2
  • nemaline myopathy 5
  • nemaline myopathy 5B, autosomal recessive, childhood-onset
  • nemaline myopathy 5C, autosomal dominant
  • nemaline myopathy 6
  • nemaline myopathy 7
  • nemaline myopathy 8
  • nemaline myopathy 9
  • severe congenital nemaline myopathy
  • typical nemaline myopathy
MONDO:0018958Orphanet 607MedGen 61528

Centronuclear myopathy (including X-linked myotubular myopathy)

Congenital myopathies with centrally placed nuclei in muscle fibers, caused by MTM1, DNM2, BIN1 and other genes; the X-linked myotubular form (MTM1) is often severe in boys.

Genes analysed

Also known as

CNM; myopathy, centronuclear; myopathy, myotubular

Includes 9 related subtypes ↓
  • autosomal dominant centronuclear myopathy
  • autosomal recessive centronuclear myopathy
  • congenital myopathy with internal nuclei and atypical cores
  • myopathy, centronuclear, 2
  • myopathy, centronuclear, 5
  • myopathy, centronuclear, 6, with fiber-type disproportion
  • symptomatic form of X-linked centronuclear myopathy in female carriers
  • X-linked myotubular myopathy
  • X-linked myotubular myopathy-abnormal genitalia syndrome
MONDO:0018947Orphanet 595MedGen 104495

ACTA1-related myopathy (alpha-actinopathy)

A spectrum of congenital and adult-onset myopathies caused by variants in the skeletal muscle alpha-actin gene, ACTA1, with weakness, low muscle tone and breathing difficulties.

Genes analysed

Also known as

ACTA1 disease; actin myopathy; actinopathy; alpha actinopathy

Includes 4 related subtypes ↓
  • cap myopathy
  • congenital myopathy 2a, typical, autosomal dominant
  • progressive scapulohumeroperoneal distal myopathy
  • zebra body myopathy
MONDO:0100084

TTN-related myopathy

Skeletal muscle disorders caused by variants in TTN, which encodes the muscle protein titin, with onset from birth to adulthood.

Genes analysed

Also known as

congenital myopathy related to TTN; TTN myopathy

Includes 15 related subtypes ↓
  • autosomal dominant titinopathy
  • autosomal recessive centronuclear myopathy
  • autosomal recessive distal titinopathy
  • autosomal recessive limb-girdle muscular dystrophy type 2J
  • autosomal recessive titinopathy
  • dilated cardiomyopathy 1G
  • early-onset myopathy with fatal cardiomyopathy
  • Emery-Dreifuss-like muscular dystrophy
  • hypertrophic cardiomyopathy 9
  • myopathy, centronuclear, 2
  • myopathy, centronuclear, 5
  • myopathy, myofibrillar, 9, with early respiratory failure
  • tibial muscular dystrophy
  • titinopathy with congenital contractures
  • TTN-related myopathy, dominant-negative TTNsv
MONDO:0100175

SELENON-related congenital myopathy with rigid spine

Autosomal recessive

A congenital myopathy caused by SELENON variants, with early stiffness of the spine, scoliosis and weakness of the breathing muscles.

What a diagnosis changes

Regular checks of breathing function are recommended, because breathing weakness can develop while walking is still preserved.

Genes analysed

Also known as

CMYO3; desmin-related myopathy with Mallory body-like inclusions; early-onset desmin-related myopathy; MDRS1; minicore myopathy, severe classic form; multicore myopathy, severe classic form; multiminicore disease, severe classic form; muscular dystrophy, congenital, Eichsfeld type; muscular dystrophy, congenital, merosin-positive, with early spine rigidity; SEPN1-related myopathy; rigid spine muscular dystrophy 1; rigid spine syndrome caused by mutation in SELENON; RSMD1; SELENON rigid spine syndrome; SELENON-related myopathy

MONDO:0100100OMIM 602771Orphanet 84132

MYH7-related skeletal myopathy

Autosomal dominant

Skeletal muscle disorders caused by MYH7 variants, including Laing distal myopathy and myosin storage myopathy; some people also develop heart muscle disease.

Genes analysed

Also known as

distal myopathy type 1; Laing distal myopathy; MPD1; myopathy, distal, 1; myopathy, distal, early-onset, autosomal dominant; myopathy, late distal hereditary; myosin storage myopathy

MONDO:0008050OMIM 160500Orphanet 59135MedGen 1647391

Limitations

  • Part of the NEB gene (exons 82 to 105) is repeated three times in the genome, so variants in this region are hard to detect. The NEB exon 55 deletion common in people of Ashkenazi Jewish ancestry is a structural variant that may also be missed.

Other musculoskeletal conditions

All conditions →

One test. A lifetime of answers.

One kit, sent to your home. Your entire genome sequenced at the clinical standard used for diagnostic decisions. Physician-ready reports delivered to your Genome Manager in 6–8 weeks — permanent and updated as science advances.

From $449

Free shipping · Results in 6–8 weeks

Premium adds $99 per kit for the first year.

Order with Premium