Limb Girdle Muscular Dystrophy
The limb girdle muscular dystrophies (LGMD) is so called because they generally cause weakness in the shoulder and pelvic girdles, i.e. the big muscles around the top (proximal) part of arms and legs (hip, thigh and shoulder muscles), are most affected. Weakness of the legs is usually noticed before that of the arms. The muscles of the face are typically unaffected.
Common features
LGMD often present differently in different affected people, even within the same family, with regards to the age of onset, areas of muscles weakness, heart and respiratory involvement, rate of progression and clinical severity. Different types of LGMD may have different clinical presenting features. However, the common features to all affected people in this group are the weakness of the big muscles of the legs and/or arms. This results in frequent falls, difficulty in running, climbing stairs or rising from the floor. As the condition progresses, people may have problems with walking and may need to use a wheelchair over time. The involvement of shoulder and arm muscles can lead to difficulty in raising arms over head and in lifting objects. In some types of LGMD, the heart and breathing muscles may also be affected. Therefore regular checking of heart and breathing function is needed.
Causes
There are many different genetic faults associated with LGMD.
Diagnosis
Complex tests may be needed to work out the causes of LGMD in an individual affected person, e.g. a muscle biopsy and a blood sample for DNA testing. Muscle enzymes (Creatine Kinases) are usually elevated.
Emerging treatments
There is currently no US Food and Drug Administration (FDA)-approved treatment for LGMD. However, several investigatory drugs are undergoing clinical trials, including:
- BBP-418 (ribitol), an oral drug specific for patients with LGMD2I/R9 (phase 3 trial: https://clinicaltrials.gov/study/NCT05775848)
- ATA-200, a gene therapy for patients with LGMD2C/R5 (phase 1b/2 trial: https://clinicaltrials.gov/study/NCT05973630)
- AB-1003, a gene therapy for patients with LGMD2I/R9 (phase 1/2 trial: https://clinicaltrials.gov/study/NCT05230459)
- SRP-9003 (bidridistrogene xeboparvovec), a gene therapy for patients with LGMD2E/R4 (phase 3 trial terminated: https://clinicaltrials.gov/study/NCT03652259)
Other useful information
Here is a list of additional websites that you may find more information on LGMD:
- (台灣彰化基督教醫院 – TW) 罕病介紹
- (Loop Community Muscular Dystrophy Association - AUS) Limb Girdle Muscular Dystrophy (LGMD)
- (Muscular Dystrophy Association - NZ) Limb Girdle Muscular Dystrophy
- (National Organization for Rare Disorders - US) Limb-Girdle Muscular Dystrophies
- (TREAT-NMD - UK) Limb Girdle Muscular Dystrophy (LGMD)
- (National Institute of Health - US) limb-girdle-muscular-dystrophy