DOCUMENT

JUNE 2022 InTouch | 11 Recessive and Dominant Inheritance Autosomal Recessive Inheritance An autosome is any of the chromosomes that is not a sex (X or Y) chromosome. When a disease or genetic trait is recessively inherited two copies of the gene are required (i.e one copy from each parent) for the disease or genetic trait to be expressed. Autosomal Dominant Inheritance An autosome is any of the chromosomes that is not a sex (X or Y) chromosome. When a disease or genetic trait is dominantly inherited only one copy of the gene (i.e one copy from one parent) is required for that disease or genetic trait to be expressed. Progression Progressively, muscles of the face and distal muscles, such as the lower legs, feet, forearms and hands, may become affected and lead to considerable weakness. Calf muscles may appear unusually large (pseudo hypertrophy) as fatty deposits accumulate and replace lost muscle tissue. Mobility may become increasingly restricted and 20-30 years from onset, individuals with some types of LGMD may need to use a wheelchair. Wheelchair options can be discussed with an occupational and/or seating therapist. Fatigue can be common across all the LGMD’s and for some of the sub- types muscle and joint pain can also be a feature. Late symptoms can also include contractures as scar tissue replaces normal elastic tissue. Contractures LIMB GIRDLE MUSCULAR DYSTROPHY (LGMD) result in prevention of normal movement in the joint and makes the tissue resistant to stretching. These most commonly occur in the ankles and surgery may be an option to release them. For some individuals, contractures may be an early sign. Scoliosis, an abnormal curvature of the spine, can also become an issue. Spinal bracing may be required, and in more severe cases spinal fusion surgery. An orthopaedic specialist is beneficial in monitoring the scoliosis. Weakness of the breathing and heart muscles can affect people with some types of LGMD so regular monitoring by a respiratory physician and/or cardiologist is recommended. Early detection and prompt treatment can be lifesaving. People without a genetic diagnosis should also be carefully monitored as their risk of heart and breathing problems is unknown. Many researchers have noted that progression of LGMD is often faster and more severe when the onset is earlier, in comparison to individuals who develop LGMD later in adolescence or adulthood. Additional Management of Limb Girdle Muscular Dystrophy From an early stage, it is important to undergo regular exercise and stretching programmes, with the help of a physiotherapist, to maintain muscle strength, range of movement and flexibility. Swimming is an excellent option to exercise and mobilize all muscles and joints. Treatment of Limb Girdle Muscular Dystrophy Although there are no current treatments yet for these conditions research is continuing and there are now a number of pre-clinical and clinical trials underway. See more at: https://clinicaltrials.gov/ In New Zealand patients can join Pūnaha Io Neuro-Genetic Registry & BioBank for access to trials and other research opportunities: https://www.mda.org.nz/Our- Research/Registry--Biobank Fatigue can be common across all the LGMD’s and for some of the sub-types muscle and joint pain can also be a feature. RESOURCES AND REFERENCES: MedlinePlus - Health information: https://medlineplus.gov/ency/ article/000711.htm LGMD Awareness: https://www.lgmd-info.org/about-us/ LGMDType 2: https://rarediseases.info.nih.gov/ diseases/438/limb-girdle-muscular- dystrophy-type-2d Muscular Dystrophy Assocation: https://www.mda.org/disease/limb-girdle- muscular-dystrophy