Before a hearing on the merits in any case under sections 45a-603 to 45a-622, inclusive, that is contested, the Probate Court shall, on the motion of any party other than a party who applied for the removal of a parent as a guardian, or may, on the court’s own motion or motion of the party who applied for the removal of a parent as a guardian, transfer the case to the Superior Court in accordance with rules adopted by the judges of the Supreme Court. In addition to the provisions of this section, the Probate Court may, on the court’s own motion or motion of any interested party, transfer any proceeding under sections 45a-603 to 45a-622, inclusive, to a Regional Children’s Probate Court established pursuant to § 45a-8a. If the case is transferred and venue altered, the clerk of the Probate Court shall transmit to the clerk of the Superior Court or the Regional Children’s Probate Court to which the case was transferred, the original files and papers in the case.