No single-point-of-failure can cause the loss of guidance compliant with the RNP value associated with a missed approach procedure. Typically, the aircraft must have at least dual GNSS sensors, dual flight management systems, dual air data systems, dual autopilots, and a single inertial reference unit.
Are you sure on the "and" ?
My airplane has no IRS/U, no second A/P and is RNP compliant dwon to .3.
Sorry for the offtopic.