autosomal recessive limb-girdle muscular dystrophy type R18

Autosomal recessive limb-girdle muscular dystrophy type R18 is a very rare condition that primarily affects the muscles of the hips and shoulders, leading to progressive proximal muscle weakness, myalgia, and fatigue during childhood. It is caused by pathogenic variants in the TRAPPC11 gene, which plays a role in intracellular transport processes. In addition to muscle involvement, affected children may experience hyperkinetic movements, truncal ataxia, and intellectual disability. The condition is extremely uncommon, affecting fewer than 1 in 1 million people.

The clinical presentation of this condition is multisystem, with hallmark features involving both the muscular and central nervous systems. Characteristically, affected individuals exhibit progressive limb-girdle muscle weakness that reduces ambulation over time, accompanied by myalgia and fatigue. Neurological features include hyperkinetic movements, truncal ataxia, and intellectual disability, while skeletal manifestations such as scoliosis and hip dysplasia are also reported. Less commonly, some individuals may experience ocular issues like myopia and cataract as well as seizures. Not all individuals experience every feature, and severity varies considerably.

This condition is caused by pathogenic variants in the TRAPPC11 gene. It is inherited in an autosomal recessive pattern, which means that an affected individual must inherit two copies of the altered gene, one from each parent. Because this condition is very rare and involves the inheritance of two copies of a rare variant, it is more common when parents share a common ancestor. Genetic counseling is recommended to help families understand the inheritance pattern and the 25% recurrence risk in each pregnancy when both parents are carriers.

Currently, management focuses on supportive care and symptom management, as no treatments are specifically approved for this condition. Treatment is tailored to the individual and typically involves a multidisciplinary team to address the various aspects of care. Regular surveillance and monitoring are essential to detect complications early, and interventions may include physical and occupational therapy, along with orthopedic management for skeletal issues. Genetic counseling is also recommended to provide guidance on family planning and long-term management options.

The overall course of autosomal recessive limb-girdle muscular dystrophy type R18 is variable, with outcomes influenced by symptom severity, age at diagnosis, and access to specialized care. Many individuals experience a lifelong condition with periods of stabilization interspersed with gradual progression, particularly in motor function. Outcomes described in medical literature continue to evolve as standards of care improve, and modern multidisciplinary approaches have contributed to improved quality of life for many affected individuals. Families are encouraged to connect with genetic counselors and specialists to obtain personalized guidance regarding prognosis and ongoing management.

Currently, a few clinical trials are underway exploring new treatment approaches for this condition. Individuals interested in participating in research or clinical trials can search ClinicalTrials.gov or discuss potential eligibility with their healthcare team.