Maria, like her mother, was likely a carrier of the hemophilia gene and might have passed on the disease to another generation if she had survived to have the children she dreamed of. One of Alexandra's brothers and two of her nephews, as well as one of her maternal uncles and two children of one of her first cousins were all hemophiliacs, as was Maria's brother Alexei. Maria herself reportedly hemorrhaged in December 1914 during an operation to remove her tonsils, according to her paternal aunt Grand Duchess Olga Alexandrovna of Russia, who was interviewed later in her life. The doctor performing the operation was so unnerved that he had to be ordered to continue by Maria's mother, Tsarina Alexandra. Olga Alexandrovna said she believed all four of her nieces bled more than was normal and believed they were carriers of the hemophilia gene like their mother. Symptomatic carriers of the gene, while not hemophiliacs themselves, can have symptoms of hemophilia including a lower than normal blood clotting factor that can lead to heavy bleeding during childbirth or surgical procedures such as a tonsillectomy. DNA testing on the remains of the royal family proved in 2009 that Alexei suffered from hemophilia B, a rarer form of the disease. The same testing proved that his mother and one of the four Grand Duchesses were carriers. Russians identify the grand duchess who carried the gene as Anastasia, but American scientists identified the young woman as Maria.