Duterte says he suffers from illness causing muscle weakness

President Rodrigo Duterte has revealed that he is suffering from "myasthenia gravis," a disease that causes muscle weakness.

Duterte disclosed his condition during his meeting with the Filipino community in Moscow, Russia on Saturday night (Sunday, PHL time).

During his speech, Duterte said the movements of his eyes sometimes go uncoordinated.

This was after he said he wanted to sing another duet with a Russian singer before "he gets executed" for being the sole responsible for his administration's war on drugs.

"Mag-duet lang kami ng ‘Ikaw'. Pagkatapos magtingin ako sa kanya kagaya kanina pero gusto ko siyang tingnan sa mata. Pero ang mata ko –'yung isang mata ko, dito sa mata niya. 'Yung isang mata ko, umiikot kung saan-saan pumupunta,'" Duterte said.

Ganun ako eh. May talent ako, magtingin ako sa'yo, 'yung isang mata ko bumaba... Actually my –that's myasthenia gravis. It's a nerve malfunction," he added.

Duterte said he got the disease from his grandfather.

"So, I believe really in genetics. Kung anong sa kanya, nakuha ko eh. Kamukha ako daw ng lolo ko," he added.

According to health website Mayo Clinic, myasthenia gravis is characterized by "weakness and rapid fatigue" of a person's voluntary muscles.

Among the symptoms of the disease are weakness of arm or leg muscles, double vision, drooping eyelids, and difficulties with speech, chewing, swallowing and breathing.

While people from all ages could suffer from the disease, myasthenia gravis is more common in women below 40 years old and men above 60 years old.

There is no cure for myasthenia gravis.

It was not the first time that Duterte told the public about the medical conditions he is suffering from.

The President previously revealed that he has Buerger's disease, a condition that causes constriction of the blood vessels due to nicotine, and Barrett's esophagus, a disease involving the tissue in the esophagus.

He had also admitted to having a misaligned spine as a result of a motorcycle accident years ago.

A Social Weather Stations survey released in January this year showed that at least 66 percent of Filipinos are worried about Duterte's health.

Malacañang, however, is against releasing any medical bulletin of the President, arguing the Constitution only requires disclosure in case of serious illness. —Erwin Colcol/LBG, GMA News