Name mismatch between my passport and my parents passports

Dear Sir / Madam, My mother's name in my passport is Lakshmi, but her name in her passport is Laxmi. Similarly, my Father's name in my passport is Venkateswar Rao, but his name in his passport is Venkateswara Rao. Could you please advise if there is any issue with this minor name mismatch between my passport and their passports. They want to apply USA tourist visa to visit me in the USA soon.