EARLY DEVELOPMENTAL ASSESSMENT IN INFANTS AND YOUNG BOYS WITH DUCHENNE MUSCULAR DYSTROPHY

Abstract

In the early years of life, children grow and develop fast on different developmental domains. They are supposed to achieve developmental milestones in motor skills, cognition, language, adaptive behavior and social emotional skills. Unfortunately, some children face problems during early developmental stages in one or more of these areas. By detecting abnormalities in developmental milestones early, healthcare providers can diagnose possible disabilities quickly and, if necessary, initiate targeted interventions. For this, reliable, valid and standardised outcome measures are essential. Duchenne Muscular Dystrophy is the most common form of muscular dystrophies in children. It is an X-linked recessive disorder caused by mutations in the dystrophin gene with an estimated prevalence of 1 in 3500 to 5000 male births. DMD is primarily known for its impact on the motor domain, however this disorder is also associated with cognitive, language, behavioral and social emotional problems. Overall, individuals with DMD experience progressive muscle weakness caused by absence or deficiency of dystrophin, resulting in wheelchair dependency around the age of 10 to 12 years, assisted ventilation around 20 years of age and premature death, typically between 20 and 40 years of age as a result from cardiac and/or respiratory failure. Dystrophin is a protein essential to proper muscle functioning. Furthermore, dystrophin is also expressed in the brain. So, DMD is not just a muscle disorder, but a disease that also affects the central nervous system. The first signs and symptoms arise already early in the development and can manifest in different developmental domains. Still, there is a persistent diagnostic delay, and the diagnosis of DMD is, on average, not made until 4 to 5 years of age. Better insights in the early development of infants and young boys with DMD can help in reducing the diagnostic delay and can aid in proposing and setting-up early intervention strategies. The general aim of this doctoral thesis was to contribute to the assessment and better understanding of early development in infants and young boys with DMD, using general as well as disease-specific evaluation tools.