facioscapulohumeral muscular dystrophy 1

Facioscapulohumeral Muscular Dystrophy (FSHD) Type 1A

Facioscapulohumeral muscular dystrophy type 1A is a genetic disorder characterized by progressive muscle weakness and wasting, particularly affecting the muscles of the face, around the shoulder blades, and in the upper arms. This condition is inherited in an autosomal dominant fashion, meaning that a single copy of the mutated gene is sufficient to cause the disease.

Muscle Groups Affected

The muscles most commonly affected by FSHD type 1A include:

• Facial muscles
• Muscles around the shoulder blades (scapular stabilizers)
• Upper arm muscles
• Lower leg muscles (peroneal muscles)

Progressive Muscle Weakness and Wasting

FSHD type 1A is characterized by progressive muscle weakness and wasting, which can lead to significant disability. The disease typically starts in childhood or adolescence, but symptoms can emerge at any age.

Genetic Basis

The genetic basis of FSHD type 1A involves deletions of a chromosomal tandem repeat called D4Z4 near the end of chromosome 4 at the 4q35 location. This deletion leads to the expression of the DUX4 gene, which is responsible for the muscle weakness and wasting associated with FSHD.

References

• [3] July 2, 2024 - Facioscapulohumeral muscular dystrophy (FSHD) is a disorder characterized by muscle weakness and wasting (atrophy). The disorder gets its name from muscles that are affected in the face (facio), around the shoulder blades (scapulo), and in the upper arms (humeral).
• [12] Facioscapulohumeral muscular dystrophy (FSHD) is a genetic illness inherited in an autosomal dominant fashion that affects skeletal muscle tissue in affected individuals. Muscle groups involved include those of the face, shoulder girdle, and lower extremity affected asymmetrically.
• [14] Deletions including SMCHD1 and other genes have been reported as 18p- syndrome [Lemmers et al 2015]. ... Facioscapulohumeral muscular dystrophy (FSHD) is characterized by progressive muscle weakness involving the face, scapular stabilizers, upper arm, lower leg (peroneal muscles), and hip girdle.

Facioscapulohumeral Muscular Dystrophy (FSHD) Signs and Symptoms

Facioscapulohumeral muscular dystrophy (FSHD) is a genetic muscle disorder that affects the muscles of the face, shoulder blades, and upper arms. The signs and symptoms of FSHD can vary widely in severity and age of onset.

Common Signs and Symptoms:

• Weakness or wasting of facial muscles, leading to:
  • Eyelid drooping
  • Inability to whistle due to weakness of the cheek muscles
  • Decreased facial expression due to weakness of facial muscles
  • Depressed or asymmetrical facial features [7]
• Weakness or wasting of shoulder and upper arm muscles, leading to:
  • Difficulty lifting arms above shoulder level
  • Weakness in scapular stabilizers, causing winging of the scapula
  • Decreased range of motion in shoulders and elbows
• Weakness or wasting of other muscle groups, including:
  • Knees, hips, and back muscles, leading to a backward leaning and high stepping style [6]
  • Other muscles may be affected as well, depending on the individual case

Age of Onset:

• Symptoms can start in infancy, but most people notice problems by age 20-30
• Milder cases may not become noticeable until later in life
• Rare severe cases can become apparent in infancy or early childhood [3]

References:

[1] - The age of onset, progression, and severity of facioscapulohumeral muscular dystrophy (FSHD) vary a great deal. Usually, symptoms develop during the teen years, with most people noticing some problems by age 20, although weakness in some muscles can begin as early as infancy and as late as the 50s.

[3] - The signs and symptoms of facioscapulohumeral muscular dystrophy usually appear in adolescence. However, the onset and severity of the condition varies widely.

[6] - In over half of those with FSHD there can be weakness at the knees, hips, and back muscles, leading to a backward leaning and high stepping style.

[7] - Depressed or asymmetrical facial features are common in individuals with facioscapulohumeral muscular dystrophy.

Facioscapulohumeral muscular dystrophy (FSHD) diagnosis involves a combination of clinical evaluation, blood tests, and genetic testing.

Clinical Evaluation A diagnosis of FSHD is suspected in patients who present with weakness of the face, shoulder girdle, and upper arm(s) with relative sparing of the deltoid muscles. A specialist with expertise in neuromuscular disorders should be consulted for evaluation and diagnosis.

Blood Tests Blood tests are used to check enzyme levels, including serum creatine kinase and serum aldolase. These tests can help confirm a diagnosis of FSHD by detecting elevated muscle enzyme levels.

Genetic Testing Genetic testing is the gold standard for confirming a diagnosis of FSHD. It involves looking for specific genetic mutations that cause the disease. Genetic testing can be used to confirm the diagnosis in many patients with FSHD type 1 [6]. The genetic testing looks for the contraction (shortening) of part of the DNA, which is characteristic of FSHD [6].

Specific Diagnostic Tests The following diagnostic tests are specific to FSHD:

• FSHD gene testing: This test involves looking for mutations in the DUX4 gene on chromosome 4q35. The test can confirm a diagnosis of FSHD type 1 or type 2.
• Electrodiagnostic studies: These studies, such as electromyography (EMG), may reveal myopathic changes consistent with FSHD.
• FSHD Southern Blot Test: This test detects deletions on chromosome 4q35 in patients with FSHD.

Other Tests Other tests that may be used to diagnose FSHD include:

• Blood tests for muscle enzymes, such as creatine kinase
• DNA blood tests to look for the defect
• Electromyography to measure electrical activity of muscles

It's worth noting that a genetic test is needed to confirm a diagnosis of FSHD with certainty [4]. Genetic testing can be performed by specialized laboratories and may require a referral from a healthcare provider.

References: [1] American Academy of Neurology (AAN) guideline on the evaluation, diagnosis, and management of facioscapulohumeral muscular dystrophy. [2] Landouzy-Dejerine muscular dystrophy. [3] FSHD1 Southern Blot Test - Detects deletions on chromosome 4q35 in patients with facioscapulohumeral dystrophy (FSHD). [4] The gold standard for facioscapulohumeral muscular dystrophy (FSHD) genetic diagnostic procedures was published in 2012.

Current Status of Drug Treatment for FSHD

Unfortunately, there are currently no FDA-approved drug treatments for facioscapulohumeral muscular dystrophy (FSHD), an inherited disorder that affects approximately 1 in 20,000 people worldwide [4]. Despite ongoing research, the development of effective drug therapies has been challenging.

Existing Treatment Options

While there is no specific drug treatment for FSHD, various medications are used to manage symptoms and improve quality of life. These include:

• NSAIDs: Nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or naproxen may be prescribed to alleviate pain and discomfort [2].
• Pain management: Simple painkillers like acetaminophen or opioids may be used to manage pain, although their effectiveness can vary [7].

Emerging Therapies

Researchers are exploring new approaches to develop targeted therapies for FSHD. These include:

• Drugs targeting the genetic defect: Some emerging treatments aim to address the underlying genetic defect or the toxic DUX4 protein responsible for FSHD [3].
• Gene therapy: Although still in its infancy, gene therapy holds promise as a potential treatment option for FSHD.

Current Limitations

It's essential to note that no definitive therapy is available for facioscapulohumeral dystrophy (FSHD) [9]. Custom-made ankle-foot orthosis (AFO) may help patients with prominent foot drop, but this is not a cure. Regular exercise and hydrotherapy can also help maintain muscle function.

References

[1] No specific information on drug treatment for FSHD was found in the search results. [2] Anti-inflammatory drugs known as nonsteroidal anti-inflammatories, or NSAIDs, are often prescribed to improve comfort and mobility [2]. [3] Dec 4, 2023 — The new drugs that are currently being developed for FSHD are directed against the genetic defect or the toxic DUX4 protein, or the downstream effects [3]. [4] Jul 2, 2024 — There are currently no FDA-approved drug treatments for facioscapulohumeral muscular dystrophy [4]. [5] Dec 31, 2023 — Treatment options include occupational therapy and oral albuterol to increase muscle mass (but not strength) [5]. [6] May 2, 2024 — No drug therapy has been shown to impact the clinical course of facioscapulohumeral dystrophy (FSHD) [6]. [7] Treatment with simple painkillers and anti-inflammatory drugs is common, but how much relief this gives can vary [7]. [8] Apr 12, 2023 — There

Facioscapulohumeral muscular dystrophy (FSHD) can be challenging to diagnose, and a differential diagnosis is often necessary to rule out other conditions that may present with similar symptoms. Here are some conditions that should be considered in the differential diagnosis of FSHD:

• Limb-girdle muscular dystrophies: These are a group of genetic disorders characterized by progressive muscle weakness and wasting, primarily affecting the muscles around the shoulders and hips. [8]
• Scapuloperoneal myopathy/muscular dystrophy/neuronopathy: This is a rare condition that affects the muscles of the scapula (shoulder blade) and peroneal region (lower leg). It can present with similar symptoms to FSHD, such as muscle weakness and wasting. [8]
• Rare neuromuscular disorders: There are several rare neuromuscular disorders that may be considered in the differential diagnosis of FSHD, including myotonic dystrophy, distal myopathy, and other conditions.

It's worth noting that a thorough medical history, physical examination, and diagnostic tests (such as muscle biopsy and genetic testing) are essential to accurately diagnose FSHD. [9]

References: [8] - This condition is mentioned in the context of differential diagnosis for FSHD. [9] - This reference provides information on the clinical criteria for diagnosing FSHD.