. "Whoever, being required by Federal or other law to register as a sex offender, commits a felony offense involving a minor under section 1201, 1466A, 1470, 1591, 2241, 2242, 2243, 2244, 2245, 2251, 2251A, 2260, 2421, 2422, 2423, or 2425, shall be sentenced to a term of imprisonment of 10 years in addition to the imprisonment imposed for the offense under that provision." . . .