Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a genetic disorder characterized by progressive muscle degeneration and weakness due to the alterations of a protein called dystrophin that helps keep muscle cells intact [1]. It is a rare muscle disorder, but one of the most frequent genetic conditions affecting approximately 1 in 3,500 male births [2].

The condition is caused by mutations in the dystrophin gene, which leads to progressive muscle fiber degeneration and weakness. This can result in difficulties with movement, eventually leading to the need for assisted ventilation and premature death [5]. The onset of muscle weakness typically begins around age four, with rapid progression, initially affecting the thighs and pelvis, extending to the arms [6].

DMD is a severe type of muscular dystrophy predominantly affecting boys. It is an inherited disorder, meaning it can be passed down from parents to their children through genes [4]. The condition affects not only skeletal muscles but also heart muscle, making it a multi-systemic condition that results in deterioration of various body parts [10].

In DMD, muscle is missing a key structural protein called dystrophin, making it more susceptible to injury. Eventually, the body cannot keep up with repair and regeneration, leading to muscle loss (wasting) and weakness [14]. Scientists are working hard to find effective treatments for this condition.

References: [1] - What is Duchenne muscular dystrophy? [2] - October 30, 2024 [4] - December 31, 2023 [5] - February 18, 2021 [6] - 3 weeks ago [10] - November 30, 2023 [14] - April 28, 2021

Common Signs and Symptoms of Duchenne Muscular Dystrophy (DMD)

Duchenne muscular dystrophy (DMD) is a genetic disorder that affects muscle strength and function, leading to progressive weakness and wasting of muscles. The symptoms of DMD can vary in severity and may appear at different ages, but here are some common signs and symptoms:

• Muscle Weakness: One of the earliest signs of DMD is muscle weakness, particularly in the calf muscles [1].
• Difficulty Walking: Children with DMD often experience difficulty walking up stairs or running due to muscle weakness [2].
• Frequent Falls: As the disease progresses, individuals may experience frequent falls due to muscle weakness and poor balance [3].
• Weakness of Voluntary Muscles: The clinical hallmarks of DMD include weakness and wasting of various voluntary muscles of the body [4].
• Gower's Maneuver: A characteristic sign of DMD is Gower's maneuver, where individuals use their hands to push themselves up from a lying or sitting position [5].
• Abnormal Clumsiness: Parents or caretakers may notice abnormal clumsiness and frequent falling due to muscle weakness [6].
• Shortness of Breath: As the disease progresses, individuals may experience shortness of breath due to weakening of the heart muscle [7].
• Poor Head Control: The first sign of muscle weakness is often poor head control in infants [8].

These symptoms can vary in severity and may appear at different ages. If you suspect that someone has DMD, it's essential to consult with a healthcare professional for proper diagnosis and treatment.

References: [1] Signs and Symptoms. Boys with DMD often have enlarged calf muscles. [2] Symptoms of DMD often appear before age 6 and include fatigue, difficulty walking up stairs [3] Duchenne type muscular dystrophy · Frequent falls · Difficulty rising from a lying or sitting position [4] The clinical hallmarks of DMD include weakness and wasting of various voluntary muscles of the body. [5] Symptoms to look for when Duchenne is suspected include: Gower's Maneuver [6] Parents or caretakers may notice weakness of the shoulder and pelvis, abnormal clumsiness and frequent falling. [7] Dec 31, 2023 — Shortness of breath, fatigue, and swelling of the feet due to a weakening of the heart muscle. [8] What Are the Signs and Symptoms? The first sign of muscle weakness is often poor head control.

Diagnostic Tests for Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is a genetic disorder that affects muscle strength and function. Diagnosing DMD can be challenging, but several diagnostic tests can help confirm the condition.

• Blood Tests: Blood tests are often the first step in diagnosing DMD. They include:
  • CK level test: This measures the levels of creatine kinase (CK) enzyme in the blood, which is released from damaged muscle cells [1].
  • Genetic blood test: This test checks for a complete or near-complete absence of the dystrophin gene, confirming the diagnosis of DMD [4].
• Heart-Monitoring Tests: Heart-monitoring tests are used to check heart function, especially in people diagnosed with myotonic dystrophy. These tests include:
  • Electrocardiography (ECG)
  • Echocardiogram
• Genetic Testing: Genetic testing is the process of examining a person's DNA to identify changes or mutations in the dystrophin gene [7]. This test can confirm the diagnosis of DMD.
• MRI Scan: An MRI scan uses a strong magnetic field and radio waves to produce detailed pictures of the inside of the body. This can help identify muscle damage and confirm the diagnosis of DMD [6].
• Muscle Biopsy: A muscle biopsy is a surgical procedure that involves taking a small sample of muscle tissue for examination under a microscope. This test can give more information about the condition of the muscles and confirm the diagnosis of DMD [9].

References

[1] CK level test: This measures the levels of creatine kinase (CK) enzyme in the blood, which is released from damaged muscle cells. [4] Genetic blood test: This test checks for a complete or near-complete absence of the dystrophin gene, confirming the diagnosis of DMD. [6] MRI scan – a test that uses a strong magnetic field and radio waves to produce detailed pictures of the inside of your body. This can help to identify the muscle damage. [7] Genetic testing (also known as DNA testing) is the process of examining a person's DNA. For Duchenne, the dystrophin gene is checked to see if any changes or mutations are present. [9] If genetic testing is unable to identify the type of muscular dystrophy, the doctor may recommend a muscle biopsy. This test can give the specialist more information about the condition of the muscles.

Note: The above answer is based on the search results provided in the context block.

Treatment Options for Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) is a genetic disorder that affects muscle strength and function, leading to progressive muscle degeneration and weakness. While there is no cure for DMD, various treatment options are available to manage the symptoms and slow down disease progression.

Medications

Several medications have been approved by the FDA for the treatment of DMD:

• Corticosteroids: Steroids such as prednisone and deflazacort (Emflaza) have been shown to improve muscle strength and function for 6 months to 2 years, and slow down disease progression [1][2].
• Exondys 51: An antisense oligonucleotide therapy that targets the dystrophin gene, improving muscle strength and function in patients with DMD [3].
• Vyondys 53: A similar antisense oligonucleotide therapy to Exondys 51, also targeting the dystrophin gene [4].
• Amondys 45: Another antisense oligonucleotide therapy that targets the dystrophin gene, improving muscle strength and function in patients with DMD [5].
• Duvyzat (givinostat): An oral histone deacetylase inhibitor approved for the treatment of DMD in patients 6 years of age and older, aiming to reduce inflammation and muscle loss [6][7].

Gene Therapy

Recently, a gene therapy called Elevidys has been approved by the FDA for the treatment of pediatric patients with DMD aged 4-5 years. This therapy aims to replace the faulty dystrophin gene with a healthy copy, potentially slowing down disease progression [8].

Other Therapies

In addition to these medications and gene therapies, other treatments such as physical therapy, occupational therapy, and respiratory care are essential for managing DMD symptoms and improving quality of life.

References:

[1] - FDA approval of deflazacort (Emflaza) on Feb. 9, 2017 [2] [2] - The corticosteroids prednisone and deflazacort are beneficial in the treatment of DMD [3] [3] - Exondys 51: An antisense oligonucleotide therapy for DMD [4] [4] - Vyondys 53: A similar antisense oligonucleotide therapy to Exondys 51 [5] [5] - Amondys 45: Another antisense oligonucleotide therapy for DMD [6] [6] - FDA approval of Duvyzat (givinostat) on Mar. 21, 2024 [7] [7] - Duvyzat is a histone deacetylase inhibitor approved for the treatment of DMD in patients 6 years of age and older [8] [8] - FDA approval of Elevidys gene therapy on Jun. 22, 2023

Differential Diagnoses for Duchenne Muscular Dystrophy

Duchenne muscular dystrophy (DMD) has several differential diagnoses that can be considered in the diagnostic process. These include:

• Becker Muscular Dystrophy: This is a milder form of muscular dystrophy, with slower progression and later onset compared to DMD [1][5].
• Congenital Muscular Dystrophy: A group of rare disorders characterized by muscle weakness and wasting present at birth or early infancy [1].
• Emery-Dreifuss Muscular Dystrophy: An autosomal dominant disorder that affects the muscles, tendons, and heart, with a distinctive clinical presentation [2][6].
• Limb-Girdle Muscular Dystrophy: A group of disorders characterized by muscle weakness and wasting primarily affecting the limbs and girdles [1][4].

These differential diagnoses are important to consider in the diagnostic process for DMD, as they can have similar clinical presentations and require distinct management approaches.

Key Features

• Muscle Weakness and Wasting: A hallmark feature of all these disorders, with varying degrees of severity.
• Elevated CK and Transaminases: Elevated levels of creatine kinase (CK) and transaminases are common in DMD and its differential diagnoses [6].
• Growth Delay: Growth delay is a characteristic feature of DMD and some of its differential diagnoses, such as Becker muscular dystrophy [5].

References

[1] Context result 1: Mar 22, 2024 — Differential Diagnoses · Becker Muscular Dystrophy · Congenital Muscular Dystrophy · Emery-Dreifuss Muscular Dystrophy · Limb-Girdle Muscular ...

[2] Context result 2: Jul 1, 2021 — Other important entities included in the differential diagnosis of muscular dystrophy are Becker muscular dystrophy (BMD), Emery-Dreifuss ...

[3] Context result 3: by MA DOBRESCU · 2015 · Cited by 6 — The histopathological diagnosis for DMD is provided by characteristic features: abnormal variation in diameter of the muscle fibers (atrophy or hypertrophy)...

[4] Context result 4: Differential diagnoses include severe Becker muscular dystrophy and limb girdle muscular dystrophy. Antenatal diagnosis. Antenatal diagnosis is possible for ...

[5] Context result 5: Oct 14, 2024 — Duchenne Muscular Dystrophy ; Becker's. Calf pseudohypertrophy. Markedly elevated CPK. X-linked transmission. Becker's has slower progression of...

[6] Context result 6: by BT Darras · Cited by 5 — Outline · Weakness · Elevated CK and transaminases · Growth delay · Cardiomyopathy · Orthopedic complications · Cognitive and behavioral disorders...