The right to disclaim granted by this act shall exist irrespective of any limitation imposed on the interest of the disclaimant in the nature of an express or implied spendthrift provision or similar restriction. A disclaimer, when filed as provided in this act, or a written waiver of the right to disclaim, shall be binding upon the disclaimant or beneficiary so waiving and all parties thereafter claiming by, through or under him, except that a beneficiary so waiving may thereafter transfer, assign or release his interest if such is not prohibited by an express or implied spendthrift provision. If an interest in real estate is disclaimed and the disclaimer is duly filed in accordance with the provisions of Section 4 of this act,¹ the spouse of the disclaimant, if such spouse has consented to the disclaimer in writing, shall thereupon be automatically debarred from any claim, right or interest in such real estate to which such spouse, except for such disclaimer, would have been entitled.