It is rare, inherited in an autosomal pattern, which causes degeneration of nerve fibers. There is generalized muscle weakness and destruction. It affects both men and women and is divided into four sub-categories:
A. Classic form: (75% of cases) Symptoms start at birth and include eating problems, scoliosis, hypotonia, slow movement, respiratory problems and heart failure.
B. Developing form with hand engagement (10%): There is less severe scoliosis with mild or no respiratory problems. There is hyperextensibility to the joints and muscle weakness in the hands.
C. Embryonic form with congenital multiple arthritis: (> 10%) The main symptom at birth is muscle tenderness. Perhaps there are special physical features such as big head, low position of ears and short neck, as well as respiratory problems.
D. Ophthalmoplegical type: Bleeding occurs due to weakness of the respective muscles and weakness in muscles close to the body.
The diagnosis can be made by muscle biopsy, muscle ultrasound.
There is no cure, but symptoms are managed by physiotherapy, exercises, respiratory care using ventilators, corrective orthopaedic procedures and use of feeding tubes. Vaccines for respiratory protection are recommended.
Congenital fiber type disproportion
It is a rare congenital myopathy. The main symptoms, like all myopathies, are loss of muscle tone (hypotonia), generalized muscle weakness, slow movement of the muscles, scoliosis, hip dislocations, muscle contractures and lack of reflexes, particular facial features such as long and thin face, weak muscles , arched palate. In more serious cases there is dysphagia and severe respiratory problems (rarely and cardiomyopathy). Ophthalmoplegia also occurs in 20% of cases.
Diagnosis is performed by clinical examination by specialists, muscle biopsy, electromyography, muscle ultrasound.
Treatment is symptomatic and supportive with appropriate physical therapy for muscle strengthening and contractions, as well as orthopedic care and interventions for correction of lesions.
Congenital Myopathy Batten – Turner
Extremely rare, hereditary myopathy (autosomal recessive) characterized by congenital hypotonia and its symptoms develop slowly during infancy and childhood.
Progressive hypotonia and generalized weakness. Slow development of milestones and scarcity in falls and storms. The weakness mainly concerns muscles of the pelvis, shoulders and throat. Since it does not develop during adulthood, most adults are ambulatory, although some physical activities may have been affected.
Treatment includes appropriate physical therapy, exercises and obesity avoidance.
Myosin Storage Myopathy/Hyaline Body Myopathy
It is inherited in an autosomal dominant pattern. It is characterized by a weakness that either does not worsen or develops very slowly. Usually its symptoms are perceived during childhood or later. Since can delay the acquisition of walking ability, it is necessary to walk with the assistance of a walking stick, there is a difficulty in climbing a ladder and raising hands above the shoulders. There is arched palm and scoliosis. Respiratory problems may also occur.
The diagnosis can be made by genetic testing.
Other Congenital Myopathies
1. Cap Myopathy
Autosomal recessive disorder of skeletal muscles. There can be muscle weakness, generalized hypotonia, but mainly of face muscles, neck muscles and gradually in the limbs. Moreover, there can gradually appear problems, such as swallowing, feeding since infancy, delayed motor milestones, motor difficulties, respiratory problems, eyelid ptosis, scoliosis/lordosis, long face features with severe arched palate.
2. Myotubullar Myopathy
Autosomal dominant disorder of skeletal muscles and heart, with gradual muscle weakness from any age, but mainly during adulthood.There may be cardiomyopathy, myalgia, peripheral neuropathy, and respiratory failure. There are contractures, scoliosis and rarely cataracts.
3. Brody Myopathy
Autosomal recessive disorder with muscle cramps, muscle stiffness in limbs, face (mainly in eyelids), after exposure in low temperature, with onset in childhood.
4. Distal Myopathy type II
Autosomal dominant mainly of adults, with muscle weakness in neck, arms, lower parts of legs and maybe in all legs and there is weakness in the vocal cords hence speech problems and dysphagia.
5. Cav 3-related myopathy (Tateyama type)
Autosomal recessive disorder, with features of atrophy, weakness of distal arm and leg muscles during adulthood, with painful cramps.
6. Distal myopathy type I (Laigh distal myopathy)
Autosomal dominant disorder of skeletal muscles, starting during childhood, from leg and ankle muscles and spreading to the upper limbs, with tremor, affecting also neck and face muscles.
7. Accumulative tubular myopathy
Autosomal dominant disorder mainly, but rarely it can be inherited with an autosomal recessive manner. There is gradual muscle pain, cramps and weakness since childhood, starting from the lower limbs mainly, with motordifficulty and contractures.
8. Hereditary myopathy with early respiratory failure (HMERF /Edstrom myopathy )
Autosomal dominant disorder, affecting skeletal and respiratory muscles with onset around the age of 30. Main features are respiratory and movement.
9. Hereditary myopathy with lactic acidosis
Autosomal recessive disorder of skeletal muscles. Symptoms onset since childhood and include muscle weakness, pain, fatigue, tachycardia, shallow breaths and rhabdomyolysis.
10. Early myopathy with cardiomyopathy (Salih myopathy or Salih congenital muscular dystrophy or titinopathy)
Autosomal recessive disorder affecting skeletal heart muscles. Since infancy there is muscle weakness, delayed milestones and later on there are contractures, scoliosis, and diastolic cardiomyopathy.
11. Myoclonic epilepsy myopathy sensory ataxia (MEMSA or SCAE)
Autosomal recessive disorder affecting muscle – neurologic – brain fuctions since early adulthood. The first features are problem in balance and orientation, but gradually there are repetitive spasms and sudden moves (myoclonic) in the right arm at first and they spread. Encephalopathy and myopathy occur.
12. Mitochondrial encephalopathy myopathy, lactic acidosis, and stroke – like episodes (ΜΕLAS)
Mitochondrial disorder affecting both sexes, causing problems in various systems, but particularly in brain, nerve system and muscles. Since childhood first symptoms appear with muscle weakness, pain, repetitive headaches, loss of appetite, vomiting and epileptic crisis. In more severe cases, patients experience symptoms like strokes before the age of 40. Such repetitive episodes can cause brain problems, leading to loss of vision, motor difficulties and dementia. Most of the patients have features of lactic acidosis, leading to vomiting, fatigue, muscle weakness, shortness of breath, abdominal pain and rarely muscle spasms (myoclonic), ataxia, deafness, heart and renal problems, diabetes and hormonal imbalance.
All of the above disorders could be diagnosed by:
- Genetic tests (some only by this test)
- nerve conduction tests,
- muscle biopsy,
- blood tests.
For the Standards of Care you may visit the following article: https://drive.google.com/file/d/11iOxRi9jCtlNEXp9ihHhTKJJgZGUrIe8/view?usp=sharing
To monitor clinical trials on diseases visit: https://clinicaltrials.gov/ct2/home
- Congenital Myopathies Clinical Presentation, Congenital Myopathies Clinical Presentation: History, Causes, August 30, 2017, https://emedicine.medscape.com/article/1175852-clinical.
- Genetics Home Reference, Congenital Myopathies, September 20, 2018, https://ghr.nlm.nih.gov/search?query=congenital+myopathy.
- Muscular Dystrophy Canada, Multicore Myopathy, http://muscle.ca/wp-content/uploads/2012/11/FS_Multicore_E.pdf
- Muscular Dystrophy UK, Minicore Multicore Myopathy, http://www.musculardystrophyuk.org/app/uploads/2015/02/Minicore-multicore-myopathy-2016.pdf
- Myosin storage myopathy – Genetics Home Reference,U.S. National Library of Medicine, November 16, 2017, https://ghr.nlm.nih.gov/condition/myosin-storage-myopathy#synonym
- NORD (National Organization for Rare Disorders), rare diseases, Myosin storage Myopathy, https://rarediseases.info.nih.gov/diseases/7148/myosin-storage-myopathy