obsolete autosomal dominant limb-girdle muscular dystrophy type 1A

Obsolescence and Characteristics

Limb-girdle muscular dystrophy type 1A (LGMD1A) is an autosomal dominant progressive myopathy that was once considered a distinct subtype. However, it has been largely replaced by more specific classifications of the disease.

• Definition: LGMD1A was characterized by its adult-onset, slowly progressive muscle atrophy with weakness in a limb-girdle distribution (citations [15] and [7]).
• Inheritance Pattern: It followed an autosomal dominant inheritance pattern, meaning that a single flawed gene from one parent was sufficient to cause the disease (citations [14] and [11]).
• Muscle Affected: The proximal hip and shoulder girdle muscles were primarily affected, with later involvement of distal limb muscles (citation [15]).

Current Classification

The classification of LGMD1A has become obsolete due to advances in genetic research. The disease is now subsumed under more specific categories, such as autosomal dominant limb-girdle muscular dystrophy type 1 (LGMD1) and its various subtypes (citations [14] and [11]).

Progression and Impact

The progression of LGMD1A was slow, leading to loss of ambulation only after 20 years in some patients (citation [15]). However, the exact impact on affected individuals may vary depending on the specific subtype and individual factors.

Symptoms of Obsolete Autosomal Dominant Limb-Girdle Muscular Dystrophy Type 1A

Autosomal dominant limb-girdle muscular dystrophy type 1A (LGMD1A) is a rare subtype of LGMD characterized by adult-onset proximal shoulder and hip girdle weakness [7]. The symptoms of this condition typically include:

• Weakness in the shoulders, hips, upper arms, and legs
• Progressive difficulty lifting or carrying objects due to muscle weakness
• Frequent falls due to muscle weakness in the legs
• Muscle atrophy (wasting) in the affected muscles

These symptoms are progressive and may spread to affect other muscles of the body [3]. The age at which symptoms appear can vary, but they typically begin in adulthood.

Key Features

The key features of LGMD1A include:

• Adult-onset proximal shoulder and hip girdle weakness
• Progressive muscle weakness and atrophy
• Symmetric involvement of the muscles
• Diminished or absent tendon reflexes

It's worth noting that LGMD1A is an obsolete classification, and the condition is now considered part of a broader category of LGMDs. However, the symptoms described above are still relevant to understanding the clinical presentation of this subtype.

References

[7] - A rare subtype of autosomal dominant limb girdle muscular dystrophy characterized by an adult onset of proximal shoulder and hip girdle weakness (that later spreads to other muscles). [3] - Muscle weakness and atrophy are progressive and may spread to affect other muscles of the body. [8] - Typically, these symptoms include weakness in the shoulders, hips, upper arms and legs. For example, patients may have progressive difficulty lifting or carrying objects due to muscle weakness.

Diagnostic Tests for Obsolete Autosomal Dominant Limb-Girdle Muscular Dystrophy Type 1A

Autosomal dominant limb-girdle muscular dystrophy type 1A (LGMD1A) is a rare genetic disorder characterized by progressive muscle weakness and wasting. While it has been largely replaced by more modern diagnostic methods, there are still some diagnostic tests that can be used to identify this condition.

Muscle Biopsy

A muscle biopsy is a surgical procedure where a small sample of muscle tissue is removed from the affected area for examination under a microscope. This test can help confirm the presence of LGMD1A by identifying specific changes in the muscle fibers, such as fiber size variation and internal nuclei [9].

Creatine Kinase (CK) Testing

Elevated levels of creatine kinase (CK), an enzyme found in muscles, are often associated with LGMD1A. CK testing can aid in diagnosis, particularly for autosomal recessive limb-girdle muscular dystrophies, which often cause extremely high CK levels [6].

Genetic Testing

While genetic testing is now a more common and preferred method of diagnosing LGMD1A, it was not always the case. In the past, genetic testing may have been used to confirm the presence of specific genetic mutations associated with this condition.

Other Diagnostic Tests

In addition to muscle biopsy and CK testing, other diagnostic tests such as electromyography (EMG) and nerve conduction studies (NCS) may also be used to help diagnose LGMD1A. However, these tests are not specific for this condition and should be interpreted in conjunction with clinical findings.

References

• [6] Aug 15, 2019 — Creatine kinase testing aids diagnosis.
• [9] Quite often, complex tests may be needed to work out the causes of LGMD in an individual, which may include examination of a muscle biopsy and a blood sample ...
• [1] Genetic testing has become more routinely used to obtain a diagnosis for a patient with characteristic features of LGMD. Pursuing genetic testing is a personal ...

Based on the search results, it appears that there are no specific disease-modifying treatments available for limb-girdle muscular dystrophy (LGMD) in general, including type 1A. However, I can provide some information on potential treatments that have been studied or developed for LGMD.

• Stem-cell transplantation: This has been explored as a potential treatment for LGMD, but it is still in the experimental stages [2].
• Exon skipping: This is another approach being researched to treat LGMD, which involves skipping specific exons in the gene responsible for the disease [2].
• Gene therapy: While not specifically mentioned in the search results, gene therapy has been explored as a potential treatment for various forms of muscular dystrophy, including LGMD.

It's essential to note that these treatments are still in the early stages of development and have not been proven to be effective for type 1A LGMD. The main goal of current management is supportive care, which includes maintaining mobility and functional independence, managing associated symptoms, and improving quality of life [5][6].

Unfortunately, there is no specific information on drug treatment for obsolete autosomal dominant limb-girdle muscular dystrophy type 1A in the search results provided.

References: [2] by C Bouchard · 2023 · Cited by 10 — In the last decade, multiple other potential treatments were developed and studied, such as stem-cell transplantation, exon skipping, gene ... [5] Sep 17, 2024 — The treatment of Limb-Girdle muscular dystrophy focuses on supportive care to maintain mobility and functional independence, manage associated ... [6] Dec 12, 2023 — The main goal of treatment is to manage symptoms and improve your quality of life. Treatments can vary depending on the type of LGMD and may ...

Based on the search results, it appears that there are several conditions that can be considered in the differential diagnosis for obsolete autosomal dominant limb-girdle muscular dystrophy type 1A.

• Becker Muscular Dystrophy: This is a more common condition than LGMD 1A, and it can present with similar symptoms such as muscle weakness and wasting (7).
• Duchenne Muscular Dystrophy: Another condition that can be considered in the differential diagnosis, particularly in males (7).
• Other forms of limb-girdle muscular dystrophy: The search results mention that there are at least four main reasons to make specific limb girdle muscular dystrophy subtypes differential diagnosis, including genetic counseling, cardiorespiratory risk assessment, and others (5).

It's worth noting that the search results also mention that a DNA-based molecular diagnosis is often required to differentiate between these conditions (8). Additionally, certain subtypes of LGMD 1A may have additional symptoms such as heart issues, which can aid in differential diagnosis (9).

In terms of specific distinguishing clinical characteristics, some features that can help narrow the differential diagnosis include:

• Age of onset: The age at which symptoms first appear can be an important factor in differentiating between conditions (11).
• Distribution of weakness: The predominantly proximal distribution of weakness is a characteristic feature of LGMD 1A (11).
• Cardiorespiratory risk assessment: This can be an important consideration in the differential diagnosis, particularly for certain subtypes of LGMD 1A (10).

Overall, it appears that a comprehensive evaluation of clinical features, genetic testing, and cardiorespiratory risk assessment are all important considerations in the differential diagnosis of obsolete autosomal dominant limb-girdle muscular dystrophy type 1A.

References:

• [7]
• [5]
• [8]
• [9]
• [11]
• [10]