facioscapulohumeral muscular dystrophy 2

Facioscapulohumeral muscular dystrophy type 2 (FSHD2) is a form of muscular dystrophy characterized by muscle weakness that first affects the facial muscles and upper extremities, later progressing to involve the lower extremities. The pattern of weakness is usually asymmetric.

This condition is caused by a combination of genetic mutations, specifically an SMCHD1 mutation and an FSHD-permissive D4Z4 allele [2]. This digenic inheritance pattern is unique to FSHD2 and distinguishes it from other forms of muscular dystrophy.

The symptoms of FSHD2 typically start in the facial muscles and upper extremities, with progressive weakness affecting the lower extremities over time. As with other forms of muscular dystrophy, the progression and severity of FSHD2 can vary significantly between individuals [11].

It's worth noting that FSHD2 is a rare form of muscular dystrophy, and more research is needed to fully understand its characteristics and implications for affected individuals.

References: [2] Miller DG, van der Maarel SM. Digenic inheritance of an SMCHD1 mutation and an FSHD-permissive D4Z4 allele causes facioscapulohumeral muscular dystrophy type 2. Nat Genet. 2012 Dec;44(12):1370-4. doi: 10.1038/ng.2454 [11] Description. Facioscapulohumeral muscular dystrophy-2 (FSHD2) is a form of muscular dystrophy characterized by muscle weakness that first affects the facial muscles and upper extremities, later progressing to involve the lower extremities. The pattern of weakness is usually asymmetric (summary by Lemmers et al., 2012).

Facioscapulohumeral muscular dystrophy (FSHD) type 2, also known as FSHD2, is a rare genetic disorder that affects muscle strength and function. The signs and symptoms of FSHD2 can vary from person to person, but here are some common ones:

• Muscle weakness: FSHD2 typically starts with weakness in the muscles around the eyes, mouth, shoulders, and abdominal area [1].
• Facial weakness: Facial muscle weakness is a common symptom of FSHD2, which can make it difficult to smile, whistle, or even close the eyelids properly [4].
• Abdominal muscle weakness: Weakness in the abdominal muscles can lead to a condition called Beevor sign, where the belly sticks out and the pelvis tilts forward [7].
• Weakness in other areas: In some cases, FSHD2 can also cause weakness in the muscles of the arms, legs, hips, and back, leading to difficulties with walking, standing, or even raising one's arms [5][9].

It's worth noting that the symptoms of FSHD2 can be similar to those of other muscular dystrophies, so a proper diagnosis by a healthcare professional is essential for accurate identification and treatment.

References:

[1] Signs and Symptoms · Abdominal muscle weakness · Abnormalities of the retina · Cardiac and respiratory function · Facial weakness. Facial weakness can make it hard ...

[4] Aug 1, 2014 — Weakness involving the facial muscles or shoulders is usually the first symptom of this condition. Facial muscle weakness often makes it ...

[5] Apr 12, 2023 — In over half of those with FSHD there can be weakness at the knees, hips and back. This can cause a backward leaning and high stepping style of ...

[7] by JC de

Facioscapulohumeral muscular dystrophy (FSHD) Type 2 can be diagnosed through various tests, including genetic testing.

• Genetic Testing: This is the most common method of diagnosing FSHD Type 2. Genetic testing analyzes genes associated with facioscapuloperoneal muscular dystrophy (FSHD) type 2 [7]. The test typically involves analyzing DNA from a blood sample to identify the specific genetic mutation causing FSHD Type 2 [8].
• Southern Blot: This is another method of diagnosing FSHD, which involves double digestion of genomic DNA by EcoRI alone and double digestion by EcoRI/BlnI [10]. However, it's worth noting that this method may not be as commonly used as genetic testing.
• DNA Sequencing: While not specifically mentioned in the context provided, DNA sequencing is a common technique used in genetic testing to identify specific mutations. It's possible that this test may also be used to diagnose FSHD Type 2.

It's essential to note that a diagnosis of FSHD Type 2 should only be made by a qualified healthcare professional after reviewing the results of these tests and considering other factors, such as clinical presentation and family history.

References: [7] - This test analyzes genes associated with facioscapuloperoneal muscular dystrophy (FSHD) type 2. [8] - The DNA mutation causing FSHD can be recognised from a blood sample in most cases. [10] - To confirm a diagnosis of FSHD with certainty, a genetic test is needed. Genetic testing to confirm FSHD Type 1 or Type 2.

Current Status of Drug Treatment for FSHD

Unfortunately, there are currently no FDA-approved drug treatments available for facioscapulohumeral muscular dystrophy (FSHD), an inherited disorder that affects approximately 1 in 20,000 people worldwide [4]. Despite ongoing research and development of new therapies, the current treatment options for FSHD remain limited.

Existing Treatment Options

While there are no specific drug treatments available for FSHD, some patients may benefit from:

• Pain management: NSAIDs (nonsteroidal anti-inflammatory drugs) can be prescribed to improve comfort and mobility [1].
• Physical therapy: Regular exercise and physical therapy can help maintain muscle function and improve activities of daily living [5].
• Occupational therapy: Customized occupational therapy programs can aid in improving daily living skills and maintaining independence.
• Speech therapy: Speech therapy may be beneficial for patients with FSHD who experience speech difficulties.

Emerging Therapies

Researchers are actively exploring new therapeutic approaches to address the underlying genetic defect or toxic DUX4 protein associated with FSHD. However, these emerging therapies are still in the development stage and have not yet been approved by regulatory authorities [3].

Summary of Current Treatment Options

In summary, while there are no FDA-approved drug treatments available for FSHD, patients may benefit from pain management,

Facioscapulohumeral muscular dystrophy type 2 (FSHD2) has a differential diagnosis that includes other conditions with similar symptoms. Some of the key points to consider are:

• FSHD1 vs FSHD2: The main differential diagnosis for FSHD2 is FSHD1, and the distinction between the two types will need to be made through genetic and epigenetic testing (7, 12).
• Limb-girdle muscular dystrophies: FSHD should be considered in the differential diagnosis of patients presenting with limb girdle weakness, as it can mimic some of the symptoms of these conditions (14).
• Scapuloperoneal myopathy/muscular dystrophy/neuronopathy: This condition is another differential diagnosis for FSHD, particularly when considering the involvement of the scapular and peroneal muscles.
• Rare mitochondrial myopathies: These are a rare but important consideration in the differential diagnosis of FSHD, as they can present with similar symptoms.

It's worth noting that the clinical presentation of FSHD2 is often indistinguishable from FSHD1, making genetic and epigenetic testing essential for accurate diagnosis (12).

References:

• [7] Jia FF. Mimics of FSHD1 or FSHD2. The main differential diagnosis of FSHD2 is FSHD1; the distinction will need to be made through genetic and epigenetic testing as little, if any, difference clinically can be used to deduce the subtype of FSHD (see section on clinical ...
• [12] Facioscapulohumeral muscular dystrophy type 2: an update on the clinical, genetic, and molecular findings. ... The main differential diagnosis of FSHD2 is FSHD1; the distinction will need to be made through genetic and epigenetic testing as little, if any, difference clinically can be used to deduce the subtype of FSHD (see section on clinical ...
• [14] Facioscapulohumeral dystrophy (FSHD), is a muscular dystrophy that clas-sically affects the shoulder girdle and facial muscles. It should be consid-ered in the differential diagnosis of patients presenting with limb girdle weakness. Progression is usually slow, and the condition is rarely fatal.