This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Genetics And Genetic Disorders, Subject name: Pediatrics
[{'content': 'True about mitochondrial inheritance \nSelect and explain. \nA. An offspring bom to an affected male will be affected, B. An offspring born to an affected female will be affected, C. An offspring born to an affected female will be normal, D. All of the above', 'role': 'user'}, {'content': "Answer: B \nExplanation: Ans. b (An offspring bom to an affected female will be affected) (Ref. Nelson paediatrics, Ch. 80. p. 496)Mitochondrial Inheritance# An individual's mitochondrial genome is entirely derived from the mother. Sperm contain few mitochondria, most of which are shed upon fertilization.# Mitochondrial disorders exhibit maternal inheritance; a woman with a mitochondrial genetic disorder will have only affected offspring of either sex, while an affected father will have no affected offspring.# Common manifestations include developmental delay, seizures, cardiac dysfunction, i strength and tone, as well as hearing and vision problems.# Examples include- NARP- MELAS (myopathy, encephalopathy, lactic acidosis, and strokelike episodes),- MERRF (myoclonic epilepsy associated with ragged red fibers),- Kearns-Sayre syndrome (ophthalmoplegia, pigmentary retinopathy, and cardiomyopathy).# Cells may contain a mixture of mutant and normal mitochondria, referred to as heteroplasmy.", 'role': 'assistant'}]