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14 | InTouch WINTER 2026 WHAT IS BECKER MUSCULAR DYSTROPHY? female member of the family is a carrier of the mutation and the second is whether testing for the condition in pregnancy can be offered and with what degree of reliability. The probability of being a BMD carrier is first assessed by examining the family tree. She may be an obligate genetic carrier, a possible genetic carrier, or a probable genetic carrier. Each son of a carrier female has a 1 in 2 (50%) chance of inheriting BMD through his mother’s faulty X chromosome, and similarly, each daughter has a 1 in 2 (50%) chance of being a carrier of BMD in the same way. An affected male will not pass on the gene to any of his sons, but his daughters will all be carriers. Sometimes a woman or man has mutations in the BMD gene of his or her sperm or eggs, but not in the other cells of his or her body. The mutation may even be in some sperm and/or eggs but not in others. This situation is called germline mosaicism. Germline cells are the egg and sperm cells. Genetic tests can estimate the risk that a person has germline mosaicism, and provide information regarding the risk for a person with germline mosaicism to have a child with Becker muscular dystrophy. Genetic counselling can provide diagnostic information without invasive muscle-biopsies. These may include DNA analysis and Linkage Testing. If a woman knows she is a carrier, prenatal and pre-implantation diagnoses are also possible. Clinical genetic services in NZ are available and your doctor or the MDANZ can refer you. Management of Becker Muscular Dystrophy As yet, there is no treatment that can overcome the progressive muscle weakness of BMD. It is possible, however, to minimize complications by adhering to a management programme specially designed by a team of medical professionals. The teamwill usually be headed by a paediatric specialist, and include a physiotherapist, occupational therapist, together with specialists in other areas as required. • Exercise: Both passive and active exercises play an important role in BMD management. Walking is easily achieved in the early stages, but can become more difficult Continued from previous page. as strength declines. Walking sticks and aids can be valuable in prolonging mobility for as long as possible. Swimming is good for ensuring all muscles are exercised, and the joints mobilized. Passive exercises, or assisted stretching, should be established as early as possible. A physiotherapist is invaluable in the development of an exercise programme to delay the shortening of muscles (contractures). These exercises should be undertaken on a daily basis, and will often require the assistance from parents and/ or caregivers. Moderate exercise rather than heavy strenuous exercise is The probability of being a BMD carrier is first assessed by examining the family tree. She may be an obligate genetic carrier, a possible genetic carrier, or a probable genetic carrier. Mode of inheritance. X-Linked Recessive Parents Children mutation X X X X X X X X X X X X X X X X X X Y Y Y Y Y Y Father Affected Father Unaffected Mother Unaffected Mother Carrier Son Unaffected Son Affected Son Unaffected Son Unaffected Daughter Carrier Daughter Carrier Daughter Carrier Daughter Unaffected