Muscle cell surface protein that anchors fibers to surrounding supportive tissue. Requires proper glycosylation for normal function.

Able to walk independently. Many LGMD2I/R9 patients remain ambulatory into adulthood, though mobility may decline.

A pattern of inheritance in which a child must receive two nonworking copies of a gene, one from each parent, to develop the condition. Parents who carry one nonworking copy typically do not show symptoms. ¹

A disease of the heart muscle making it harder to pump blood effectively.²

Apparent enlargement of calf muscles due to muscle fiber changes and fat replacement.

An enzyme found in muscle cells. Elevated CK levels in the blood can indicate muscle damage and are commonly seen in individuals with LGMD2I/R9.

The gradual worsening of symptoms over time. LGMD2I/R9 progression varies widely between individuals.

A group of muscular dystrophies caused by defects in the glycosylation of α-dystroglycan. LGMD2I/R9 is classified as a dystroglycanopathy.

A gene that provides instructions for making a protein involved in the proper glycosylation of alpha-dystroglycan, which is necessary for normal muscle function. Mutations in FKRP cause LGMD2I/R9.

DNA test identifying inherited gene mutations that are associated with ATTR-CM.³

A chain of specifically ordered sugar molecules added to the alpha dystroglycan glycoprotein that enables binding of alpha dystroglycan with the extracellular matrix.

A biochemical process in which a chain of specific sugar molecules ("glycan chain") are added to proteins. In LGMD2I/R9, defective glycosylation of alpha-dystroglycan weakens muscle cell integrity.

A genetic muscle disorder characterized by progressive weakness of the muscles around the hips and shoulders. LGMD2I/R9 is caused by mutations in the FKRP gene and can vary in severity from mild adult-onset weakness to more severe childhood forms.

A diagnostic procedure in which a small sample of muscle tissue is obtained for laboratory analysis. In LGMD2I/R9, biopsy may show reduced glycosylation of alpha-dystroglycan, typically assessed using protein-based assays such as western blotting.

Weakness affecting muscles closest to the center of the body, particularly those around the hips and shoulders. This form of muscle weakness is a hallmark feature of LGMD2I/R9.

Weakness of breathing muscles that may require non-invasive ventilation (CPAP or BiPAP) and pulmonary monitoring.