Bring a large pot of lightly salted water to a boil. Add pasta and cook for 8 to 10 minutes or until al dente; drain.
Melt butter in large skillet over medium heat. Saute garlic and mushrooms until golden brown. Stir in clams with juice, parsley, salt and white pepper. Cook over medium heat until hot. Toss with pasta until evenly coated. Serve garnished with Parmesan cheese.
