This phrase sets up a description or statement about the speaker's uncle's son. You would need more context to understand the complete meaning. For example:
* "El hijo de mi tío es médico." (My uncle's son is a doctor.)
* "El hijo de mi tío es muy divertido." (My uncle's son is very funny.)
* "El hijo de mi tío es mi primo." (My uncle's son is my cousin.)
Let me know if you have more context and I can help you with the translation!