Ohio Assessments for Educators (OAE) Special Education Practice Exam

What genetic condition primarily causes muscle weakness and is most common in boys?

1. Multiple sclerosis

2. Muscular dystrophy

3. Cerebral palsy

4. Spina bifida

The correct answer is: Muscular dystrophy

Muscular dystrophy is primarily responsible for muscle weakness and is most commonly seen in boys due to its genetic inheritance patterns. This group of disorders results from mutations in genes that are crucial for muscle development and maintenance. The most common form, Duchenne muscular dystrophy, affects only males because it is linked to the X chromosome; boys have one X and one Y chromosome, while girls have two X chromosomes. Thus, a single mutated copy of the gene in boys leads to the condition, while girls are more likely to be carriers without showing symptoms. In contrast, conditions like multiple sclerosis, cerebral palsy, and spina bifida have different causes and do not primarily present with muscle weakness in the same context or demographic. Multiple sclerosis is an autoimmune disease that affects the central nervous system, cerebral palsy is a neurological disorder caused by brain damage, and spina bifida is a birth defect of the spinal cord. Each of these conditions has a distinct etiology and symptomatology that separates them from muscular dystrophy's specific profile of muscle weakness impacting primarily boys.