This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
Duschene muscular dystrophy true ? 
Select and explain. 
A. Autosomal dominant, B. Onset at second decade of life, C. Universal increase in creatine kinase, D. Normal cardiac muscle fibre
C: Universal increase in creatine kinase
Answer: C: Universal increase in creatine kinase 
Explanation: Ans. is 'c' i.e., Universal increase in creatine kinase Duchenne and Becker's muscular dystrophy are X-like recessive. So expression of gene is essentially confirmed in males. Females are affected only if X-chromosome carrying the normal allele is lost or inactivated Becker is milder form with late onset and slow progression. In duchenni, onset is early with deloyed misection. Pseudohyperophy of calf muscle, glutei, deltiod, Gower sign may positive at age of 3 year. Cardiac involvement staed at 10 year of age. Histopathology shows diffuse degeneration & regeneration of muscle fibre. Serum CPX are markedly high