Muscular dystrophy (MD) is an inherited disease caused by a mutation in one of the thousands of genes in the body that controls proteins essential to muscle function. These mutations can be inherited from parents, or you could be a carrier of a spontaneous mutation that would then pass down to your children.
In limb-girdle muscular dystrophy, there is a mutation in the genes that affect the muscles around the shoulders and hips. The muscle weakness and atrophy that occurs with LGDM is progressive and can spread to other muscles in the body. The onset of the disease may occur in childhood, adolescence, or even later.
The first account by a healthcare provider of muscular dystrophy was in 1830. In the 1860s, French neurologist Guillaume Duchenne wrote a comprehensive overview of 13 boys who had progressive muscle weakness that led to their inability to walk and early deaths.
The most common form of MD, Duchenne muscular dystrophy, is named after the neurologist, but there are many other forms of muscular dystrophy. There are over 20 different types of limb-girdle muscular dystrophy.
Types of Limb-Girdle Muscular Dystrophy
There are two main types of limb-girdle muscular dystrophy—LGMD1 and LGMD2. These two groups are classified based on the way they are inherited through the genes.
In LGMD1, the disease is inherited in an autosomal dominant pattern, meaning one parent passes along the gene mutation. In LGMD2, the disease is inherited in an autosomal recessive pattern, meaning both parents carry the gene mutation but are not affected by the disorder. Under each dominant and recessive pattern lies many subtypes.
LGMD2A is the most common type of limb-girdle muscular dystrophy, accounting for 15% to 40% of all cases. LGMD2B is the second most common form, accounting for 5% to 35% of cases. LGMD1B is the most common of the dominant inheritances and accounts for 5% to 10% of LGMD cases.
There are also many other subtypes of LGMD where the gene mutation has yet to be identified. In all cases of LGMD, the symptoms are similar. However, the progression of the disease cannot be predicted, and no two people with the disease will experience the same course of the disease.
Limb-Girdle Muscular Dystrophy Symptoms
Though symptoms and progression can vary greatly between each person with LGMD, there are many similarities. The most common symptoms of LGMD begin with muscle weakness and atrophy that occur in the muscles nearest the hips.
This can cause symptoms such as:
A waddling gaitDifficulty standing from a sitting positionDifficulty walking up stairsSore musclesJoint pain
Eventually, muscle weakness may affect the muscles of the shoulders, which can cause symptoms such as:
Difficulty raising arms overheadTrouble carrying heavy objectsSore musclesJoint pain
Other abnormalities may develop along with these symptoms. These can include:
Scoliosis (a curvature of the spine from side to side in an “S” shape) Lordosis (a forward to back curvature of the spine) Restricted movement in the joints Overgrowth of other muscles, such as the calves
In some forms of LGMD, the heart and respiratory muscles can be affected causing symptoms such as:
Cardiomyopathy (a weakening of the heart muscle)FatigueAn irregular heartbeatHeart failureDifficulty swallowingSlurred speechBreathing difficulties
Causes
Limb-girdle muscular dystrophy is caused by a genetic inheritance. In LGMD, the genes that are normally associated with the proteins necessary for muscle function are faulty. When this occurs, the muscle fibers do not work properly. Over time, the muscles become weaker and symptoms appear.
Diagnosis
To diagnose limb-girdle muscular dystrophy, your healthcare provider will perform a physical exam and take a thorough history of your own health and your family’s.
Healthcare providers will often then run a blood test to check your level of creatine kinase (CK), which is an enzyme that leaks from damaged muscles. If CK levels are high, your muscles are being destroyed by an abnormal process, which could be muscular dystrophy or inflammation. More testing is usually necessary to find the cause.
Your practitioner may order electromyography, which tests the electrical activity of the muscles and nerves. In some cases, a biopsy of the muscle will be ordered to determine if the muscle proteins in the cells are missing or not in the right combinations.
When LGMD is suspected, further bloodwork may be done. DNA testing is becoming more common and can help determine the exact type of LGMD and which gene is involved in the disease process.
Treatment
While there is no cure for LGMD or any disease-modifying treatments at the moment, there are ways to manage the symptoms to maintain mobility and independence and limit complications. Treatment for LGMD includes several modalities to maximize the quality of life.
Assistive Devices
Basic devices like a cane or long-handled reacher can help make walking and completing basic tasks easier as weakness progresses. If you experience frequent falls, a power wheelchair or scooter can help you regain independence and greatly reduce fatigue.
Diet
Though there is no specific diet known to affect the course of LGMD, maintaining adequate nutrition with the disease is important. If you have difficulty swallowing or arm weakness that inhibits your ability to eat, you could experience malnutrition.
In this case, it is best to be seen by a gastroenterologist who can evaluate your situation. They may teach you techniques to improve swallowing, or in more extreme cases, place a feeding tube.
If you are overweight, your healthcare provider may advise you on preventing weight gain or reducing your weight because carrying larger amounts of weight on your body can put added stress on already weakened muscles.
Physical Therapy and Exercise
Your healthcare provider may prescribe physical therapy to help you maintain mobility, prevent contractures, and allow for greater motion in the joints.
Sometimes you may need occupational therapy, which can help you find ways to complete tasks related to work, recreation, or daily living. For example, they may provide arm supports to make using a computer easier.
There are differing opinions on the types of exercise that are best for LGMD. However, it has been noted to avoid exercising to the point of exhaustion. Some experts have found that swimming and water exercises are a great way to keep muscles toned without stressing them too much.
Ventilation Systems
If your breathing function is declining and you experience difficulty breathing, daytime sleepiness, or sleep-disordered breathing, you may find a noninvasive ventilation system like a BiPAP can help.
Heart Monitoring
Though the heart is not as affected as often in LGMD as in other muscular dystrophies, you may still need close monitoring with electrocardiograms, magnetic resonance imaging (MRI), or other heart studies.
In some cases, medications or devices such as pacemakers may become necessary. If you develop severe congestive heart failure, heart transplantation may be needed.
Prognosis
Though each course of LGMD is different for everyone, it has been noted that experiencing childhood onset of LGMD results in a more severe disorder that progresses more rapidly than cases that occur in adolescence or adulthood.
Coping
Living with a chronic illness can sometimes feel isolating. Connecting with others who are experiencing the same disease process can help you feel less alone. Finding support groups online or on social media can be helpful. A great place to start is the Muscular Dystrophy Association.
A Word From Verywell
Learning to manage limb-girdle muscular dystrophy may feel overwhelming, but your quality of life is important, and there are ways to improve it even as your symptoms change and evolve. Do not be afraid to ask your healthcare provider for the support you need, whether through a referral to a physical therapist, occupational therapist, or other specialists.
