Suhair al-Bata'a, who went by the nickname Soo-Soo, died of a "sharp drop in blood pressure resulting from shock trauma," according to The Huffington Post's translation of a report by Egyptian news website Al Masry Al Youm on the autopsy.
The doctor who performed the circumcision allegedly offered the family 20,000 Egyptian pounds (about $2,900) to keep quiet about the incident, said the girl's uncle, Mohammed al-Bata'a, according to Al Masry.
The doctor, who is not named in Al Masry's article, had circumcised the girl's older sister, Amira, two years earlier, her parents told the news outlet.
Egypt's National Council for Women called the incident a criminal act that showed "extreme savagery," and called on the government to investigate the issue and punish those responsible, Al Arabiya reported.
The death of a 12-year-old girl from a circumcision procedure in 2007 prompted Egypt to outlaw the practice, according to The Guardian. The country had banned such procedures a decade earlier, but continued to allow them under certain circumstances.
The controversial practice, also known as female genital mutilation, is widespread in Egypt. According to a 2005 UNICEF study cited by the Guardian, "96 percent of Egyptian women aged 15 to 49 who had ever been married reported they had been circumcised."
Mohamed Omar contributed to this story.