Can dysphagia lead to a malnutrition?

Yes. Dysphagia is difficulty swallowing and this difficuly could lead to not wanting to eat in a healthy, sustaining way. Get the problem fixed.
Yes. Anytime you can't swallow properly, you run the risk of not eating all of the food types, particularly protein (meat) and thereby can become malnourished. Most patients who have trouble swallowing often will drink complete nutrition drinks (like ensure) to make sure they are getting all the nutrients. Get prompt medical attention to try to fix the problem. Often something can be done to help.