Maria and Consolata Mwakikuti, who were joined at the abdomen, became minor celebrities in Tanzania where the media had closely followed their path through high school.
Their admission to the Ruaha Catholic University in Iringa in September 2017 had marked a first in a country where disabled people are often marginalised or abandoned at birth.
They had begun a course in education with a view to becoming teachers in history, English and Swahili, when they became ill in January, notably suffering from cardiac problems.
“I am saddened by the death of twins, Maria and Consolata. When I last visited them at hospital they prayed for the nation. My condolences to their family… Rest in peace my children,” President John Magufuli tweeted.
After an apparent improvement in their health, the sisters continued their treatment at a hospital near their university, where they died on Saturday.
The twins were abandoned by their mother after the death of their father, and later taken in by a Catholic mission.
In an emotional statement on state television last July, Maria urged parents not to “hide or lock up their handicapped children”.
“They must know they as human beings, handicapped or not, are equal and have the same rights,” she said.
At the time, the sisters, who enjoyed knitting and cooking together, thanked the teachers who helped them through high school, as well as the government who provided a vehicle to take them from their home to school each day.
“We didn’t expect this day to come, it is by the grace of God that we are here today,” said Consolata, the chattier of the two, on their admission to university.