Fatal infantile hypertonic myofibrillar myopathy (FIHMM) is a rare, inherited neuromuscular disorder that affects the muscles of the body. It is characterized by increased muscle tone (hypertonia) and progressive muscle weakness. Symptoms usually begin in infancy and can include difficulty feeding, delayed motor milestones, and muscle stiffness. FIHMM is caused by mutations in the MYH7 gene, which is responsible for producing a protein called myosin that is essential for muscle contraction. The disorder is usually fatal in infancy or early childhood.

The symptoms of Fatal infantile hypertonic myofibrillar myopathy (FIHM) include:

-Muscle Weakness and Hypotonia (low muscle tone)
-Difficulty breathing
-Feeding difficulties
-Delayed motor milestones
-Developmental delay
-Cardiac arrhythmias
-Liver and kidney dysfunction
-Growth retardation
-Respiratory failure
-Seizures
-Hypoglycemia
-Hypocalcemia
-Hypomagnesemia
-Hyperkalemia
-Hyponatremia
-Hyperammonemia
-Lactic acidosis

Fatal infantile hypertonic myofibrillar myopathy is a rare genetic disorder caused by mutations in the RYR1 gene. This gene is responsible for the production of a protein called ryanodine receptor 1, which is involved in the regulation of calcium release from the sarcoplasmic reticulum in muscle cells. Mutations in this gene can lead to an abnormal increase in calcium release, resulting in increased muscle tone and contractions. This can lead to muscle weakness, stiffness, and eventually death in infancy.

Unfortunately, there is no known cure for Fatal infantile hypertonic myofibrillar myopathy. Treatment focuses on managing symptoms and providing supportive care. This may include physical therapy, occupational therapy, speech therapy, and nutritional support. Medications may also be prescribed to help manage muscle spasms, pain, and other symptoms. In some cases, surgery may be recommended to help improve mobility and reduce pain.

1. Autosomal recessive inheritance
2. Mutations in the SEPN1 gene
3. Male gender
4. Premature birth
5. Low birth weight
6. Respiratory distress
7. Feeding difficulties
8. Muscle weakness
9. Hypotonia
10. Cardiac arrhythmias
11. Cardiomyopathy
12. Abnormalities of the diaphragm
13. Abnormalities of the rib cage
14. Abnormalities of the spine
15. Abnormalities of the hips
16. Abnormalities of the feet
17. Abnormalities of the eyes
18. Abnormalities of the brain

At this time, there is no known cure for Fatal infantile hypertonic myofibrillar myopathy. However, there are medications that can help manage the symptoms of the condition. These medications include muscle relaxants, anticonvulsants, and medications to help with pain and spasticity. Additionally, physical and occupational therapy can help improve muscle strength and coordination.