Egypt

Article 160 states:

If on account of a temporary impediment, the President of the Republic is rendered unable to carry out the presidential functions, the Prime Minister acts in his place. If the Presidential office becomes vacant, due to resignation, death, permanent disability to work or any other reason, the House of Representatives announces the vacancy of the office. If the vacancy occurs for any other reason, the House announces it with a two-thirds majority. The House notifies the National Elections Commission, the Speaker of the House of Representatives temporarily assumes presidential powers.  In  the  event  the  House  of  Representatives  is  dissolved,  the  General  Assembly  of  the  Supreme Constitutional Court and its chairman replace the House of Representatives and its Speaker.   In all cases, a new president must be elected during a period not exceeding 90 days from the date the office becomes vacant. In such a case, the presidential term commences as of the date the result of elections is announced.  The interim President is not allowed to run for this office, request any amendment to the Constitution, dissolve the House of Representatives or dismiss the government.
 

Article 233 states:

If on account of a temporary impediment, the Interim President of the Republic is rendered unable to exercise his powers, the Prime Minister acts in his place. If the Interim Presidential office becomes vacant, due to resignation, death, permanent inability to work or any other reason, the most senior Vice-President of the Supreme Constitutional Court replaces him.

Excerpts from the Constitution of the Arab Republic of Egypt (2014)

Article 3 states:

The exercise of political rights is suspended with regard to the persons mentioned hereinafter....

• (2) Persons affected by mental illness and placed under custody, during their period of custody.

Article 24 states:

…In  the  case  of  House  of  Representatives  or  Shura  Council  elections,  each individual candidate and list representative shall have the right to deploy an agent, registered in the voters’ register at the General Committee’s register, to represent him in the polling centre or the general committee. If half an hour  after  scheduled  time  for  polling  passed  with  the  number  of  agents being  less  than  2,  the  head  of  the  station  shall  complete  the  number  of agents from among the literate present registered candidates…

Article 25 states:

If one of the committee members or its secretary is absent temporarily, the committee’s head shall appoint at alternate from among the attending voters who can read and write.

Article 29 states:

…Blind and other voters with a disability who cannot record their views on the election or referendum ballot papers without assistance may express their choice verbally in a manner such that only the committee members can hear. The secretary of the polling station committee shall record the voter’s choice on his ballot-paper, and the head of the polling station committee shall sign it and record next to the voter’s name on the voter list that the voter expressed his choice according to this procedure. These voters may also delegate a person to attend voting with them before the polling station committee, to write their electoral or referendum choice on the ballot papers they receive from the head of the committee. This delegation shall be recorded in the minutes.

Excerpts from Law No. 73 on Regulating the Exercise of Political Rights (1956, last amended 2013)