Question

Which of the following is a correct match-

• A. Down syndrome = $21^{st}$ Chromosome
• B. Sickle cell anaemia = X-Chromosome
• C. Haemophilia =Y-Chromosome
• D. Parkinson disease =X & Y Chromosome

Answer 1

Answer: (A)

Down syndrome = $21^{st}$ Chromosome

Answer 2

Down's syndrome (Mongolian Idiocy, j Mongolism) is caused by the presence of an extra chromosome number 21. The infant has a characteristic ; face with a flat nasal bridge, brush field spots, protuding tongue, small ears and cardiac lesions. All affected children have mental retardation (moderate), short stature and autoimmune abnormalities. All males are infertile and females have reduced fertility. Sickle cell anaemia is not a sex linked ( X- linked) disease but an autosomally inherited recessive trait. Hemophilia is X-linked but not holandric/Y-linked. Parkinson's disease is a degenerative disease due to absence of neurotransmitter substance "dopamine" from brain. It is not at all hereditary.