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	'''EMARDD''' is short for '''early-onset myopathy, areflexia, respiratory distress and dysphagia'''. It is a rare congenital myopathy linked to biallelic pathogenic variants in the [[MEGF10]] gene.

EMARDD (Early-Onset Myopathy, Areflexia, Respiratory Distress, and Dysphagia) is a rare genetic disorder characterized by a combination of muscle weakness, respiratory problems, feeding difficulties, and neurological abnormalities. It is considered a severe and progressive condition that typically presents in infancy or early childhood.
	The condition usually begins in infancy or early childhood. It mainly affects muscle strength, reflexes, breathing and swallowing, although the severity can vary between individuals.

== Symptoms and Clinical Presentation ==
The clinical features of EMARDD can vary among affected individuals but commonly include:
	== Name ==
	The name describes the main features:

# Early-Onset Myopathy: EMARDD is characterized by muscle weakness and hypotonia (reduced muscle tone) that typically manifests in infancy or early childhood. The muscle weakness can affect various muscle groups, including those responsible for movement and breathing.
# Areflexia: Areflexia refers to the absence or reduced reflexes. Individuals with EMARDD may have diminished or absent deep tendon reflexes, such as the knee-jerk reflex. Areflexia contributes to the overall muscle weakness observed in this disorder.
# Respiratory Distress: Respiratory difficulties are a hallmark feature of EMARDD. Affected individuals may experience breathing problems, such as shortness of breath, rapid breathing, or recurrent respiratory infections. In severe cases, respiratory failure may occur, requiring respiratory support or mechanical ventilation.
# Dysphagia: Dysphagia, or difficulty swallowing, is commonly observed in individuals with EMARDD. Feeding difficulties can lead to poor weight gain, malnutrition, and related health issues.
# Neurological Abnormalities: Some individuals with EMARDD may exhibit additional neurological symptoms, such as developmental delay, intellectual disability, abnormal eye movements (nystagmus), or seizures. The severity and specific neurological features can vary.
	* '''early-onset myopathy''', meaning muscle disease beginning early in life
	* '''areflexia''', meaning reduced or absent reflexes
	* '''respiratory distress''', often linked to weakness of the diaphragm and breathing muscles
	* '''dysphagia''', meaning difficulty swallowing

== Genetics and Inheritance ==
EMARDD is caused by mutations in the [[TRPV4\|TRPV4 gene]], located on [[chromosome 12q24.11]]. The TRPV4 gene encodes a protein called transient receptor potential vanilloid 4, which plays a role in calcium transport and ion channel regulation.
	EMARDD is also described as MEGF10-related myopathy. Some sources describe a milder variant in which symptoms are less severe or progress more slowly.

EMARDD is inherited in an autosomal recessive manner, which means that affected individuals inherit two copies of the mutated TRPV4 gene, one from each parent who are usually carriers of the condition. Carriers of a single mutated TRPV4 gene are typically unaffected.
	== Cause and Inheritance ==
	EMARDD is caused by pathogenic variants in both copies of MEGF10. The inheritance pattern is autosomal recessive, so parents are usually unaffected carriers when a child is affected.

== Diagnosis and Management ==
Diagnosing EMARDD involves a combination of clinical evaluation, thorough physical examination, and genetic testing. Muscle biopsies and electromyography (EMG) may be performed to assess muscle structure and function. Genetic testing can identify mutations in the TRPV4 gene and confirm the diagnosis.
	MEGF10 is involved in muscle development and repair. When the gene is not working properly, muscle function can be impaired from early life.

Management of EMARDD focuses on addressing the specific symptoms and optimizing quality of life. This often involves a multidisciplinary approach that includes pediatricians, neurologists, pulmonologists, speech therapists, and nutritionists.
	EMARDD should not be confused with TRPV4-related neuromuscular disorders. TRPV4 can cause other neuromuscular and skeletal conditions, but the recognised cause of EMARDD is MEGF10.

Treatment strategies may include:
	== Symptoms ==
	Typical features include:

* Respiratory Support: Individuals with respiratory distress may require assisted ventilation or respiratory support to ensure adequate oxygenation and ventilation.
* Physical and Occupational Therapy: Physical and occupational therapy can help improve muscle strength, mobility, and motor skills.
* Feeding Support: Management of dysphagia and feeding difficulties may involve working with speech therapists and nutritionists to ensure adequate nutrition and hydration. In some cases, a feeding tube may be necessary.
* Seizure Management: If seizures occur, antiepileptic medications may be prescribed to help control and manage seizure activity.
	* early muscle weakness
	* low muscle tone
	* reduced or absent deep tendon reflexes
	* breathing difficulty
	* feeding and swallowing problems
	* scoliosis
	* joint contractures
	* delayed motor milestones

== Prognosis ==
The prognosis for individuals with EMARDD can vary depending on the severity of symptoms and the management provided. As EMARDD is a progressive condition, the symptoms typically worsen over time. Respiratory complications can be life-threatening and may require ongoing medical intervention.
	Some affected children have reduced fetal movement before birth. Muscle biopsy may show myopathic or dystrophic changes.

== Research and Future Perspectives ==
Research into EMARDD is ongoing to better understand the underlying mechanisms and develop potential treatments. Further studies are needed to elucidate the role of TRPV4 mutations in the development and progression of EMARDD, as well as to explore potential therapeutic targets.
	The breathing problems are especially important. Some affected people require ventilatory support, and severe cases may become ventilator-dependent early in life.

Collaboration among researchers, clinicians, and affected individuals and their families is crucial for advancing knowledge about EMARDD and improving the care and quality of life for those affected by this rare genetic disorder.
	== Diagnosis ==
	Diagnosis is based on clinical features, neurological and muscle assessment, respiratory assessment and genetic testing. MEGF10 testing can confirm the diagnosis when the clinical picture fits.

	Other tests may include muscle biopsy, electromyography, respiratory function tests, swallowing assessment and imaging for scoliosis or joint problems.

	Because EMARDD is rare, diagnosis may involve a specialist neuromuscular team and comparison with other congenital myopathies.

	== Management ==
	Management is supportive and usually involves several specialists. Care may include:

	* respiratory monitoring and ventilatory support
	* feeding and swallowing support
	* physiotherapy
	* occupational therapy
	* orthopaedic care for scoliosis and contractures
	* nutrition support
	* genetic counselling for the family

	There is no established cure. Treatment aims to protect breathing, maintain function where possible, reduce complications and support quality of life.

	== Outlook ==
	The outlook varies. Severe cases can cause major breathing problems in infancy or childhood. Milder cases may follow a longer course with more gradual loss of strength.

	The variability is one reason detailed clinical assessment matters. People with the same broad diagnosis may have different levels of mobility, respiratory need and daily support.

	== Research ==
	Research on EMARDD is limited because the condition is rare. Published case reports and small series help define the MEGF10 disease spectrum, the range of severity and the practical care needs of affected people.

	== See Also ==
	* [[MEGF10]]
	* [[Congenital_Myopathy]]
	* [[TRPV4]]
	* [[Neuromuscular_Disorders]]

== References ==	== References ==
	* [https://rarediseases.info.nih.gov/diseases/12199/megf10-related-myopathy GARD: MEGF10-related myopathy]
	* [https://panelapp.genomicsengland.co.uk/panels/225/gene/MEGF10/ Genomics England PanelApp: MEGF10]
	* [https://pmc.ncbi.nlm.nih.gov/articles/PMC11627526/ Severe Scoliosis as the Clue for an Early Onset Myopathy, Areflexia, Respiratory Distress, and Dysphagia]
	* [https://www.actamyologica.it/article/view/126 Acta Myologica: Congenital myopathy associated with a novel mutation in MEGF10]

# Madeo AC, Kamberos NL, Louis CF. (2014). Ca2+ homeostasis in the pathogenesis of early onset and malignant autosomal recessive forms of osteogenesis imperfecta. Cell Calcium. 2014; 56(3): 175-180.
# Abdul-Sater Z, et al. (2019). EMARDD: A new phenotype of TRPV4 mutation. J Hum Genet. 2019; 64(6): 553-558.
# Dai J, et al. (2010). Novel de novo TRPV4 mutations in patients with congenital distal spinal muscular atrophy. J Neurol Neurosurg Psychiatry. 2010; 81(7): 666-670.
# Baple EL, et al. (2014). Mutations in KPTN cause macrocephaly, neurodevelopmental delay, and seizures. Am J Hum Genet. 2014; 94(1): 87-94.
	[[Category:Genetics]]
	[[Category:Medicine]]
	[[Category:Neuromuscular Disorders]]