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: Medicine
The "sick cell syndrome" is characterized by - 
Select and explain. 
A. Hyponatremia, B. Hypernatremia, C. Hypokalemia, D. Hyperkalemia
A: Hyponatremia
Answer: A: Hyponatremia 
Explanation: None