Chinese scientists help families with rare diseases block the transmission of diseases in families

At the Reproductive Medicine Center of Peking University Third Hospital, medical staff and Tongtong's family celebrated her 20th birthday. (Photo courtesy of Peking University Third Hospital)

Beijing, 19 Oct (Xinhua) -- The Reproductive Medicine Center of the Third Hospital of Peking University recently held a special birthday party. Tong Tong, a patient with "Cocairn's syndrome" with progeria symptoms, spent her 20th birthday here with her parents, family and medical staff.

Celebrating Kirito's birthday was also her younger brother Dazhuang. Thanks to the "preimplantation embryo single-gene diagnosis technology" carried out by the hospital, the known pathogenic genes can be diagnosed at the embryonic level, so that The parents of TongTong have a strong body that does not carry the disease-causing genes, and block the transmission of Cocairn's syndrome in the family.

In recent years, the Center for Reproductive Medicine of peking university third hospital has completed embryo diagnosis for more than 1,000 families through the "preimplantation embryo single gene diagnosis technology", involving 288 kinds of single gene genetic diseases, so that the next generation of these families plagued by genetic diseases can be spared from diseases.

Cocairn's syndrome, first reported in 1936 by the British physician Dr. Cocairn, is a very low incidence of autosomal recessive disease, patients with symptoms such as premature aging, short stature, deafness and other symptoms, the average life expectancy is only 12 years.

Huang Yu, deputy director of the Department of Genetics, Peking University Medical College, introduced that after analyzing the gene mutation sites of Tong Tong and his parents, it was found that the two pathogenic mutation sites came from both parents, both parents carried the disease-causing gene but did not get sick, and the children had a 1/4 chance of getting sick, 1/2 of the chance of carrying the causative gene but not getting sick, and 1/4 of the chance of not carrying the disease-causing gene. Kirito is the unlucky 1/4.

Since 2014, the Department of Obstetrics and Gynecology, Otolaryngology, Hematology and Other Departments of the Third Hospital of Beijing Medical College have carried out multidisciplinary joint diagnosis and treatment for Tongtong, from etiology to diagnosis, from genetic screening to assisted reproductive intervention, bringing another new life to the Tongtong family - healthy dazhuang, blocking the transmission of Cocain's syndrome in this family, and also bringing new hope to the treatment of Tongtong.

Yan Liying, deputy director of the Reproductive Medicine Center of the Third Hospital of Beijing Medical College, said that Tongtong's parents had come to the hospital in 2009 hoping to have a healthy child, but at that time, the technical ability was limited, and it was impossible to accurately diagnose the genetics with a small number of cells in the early embryo. In 2015, Tongtong's parents came to the Reproductive Medicine Center of the Third Hospital of Beijing Medical University again and got the genetic diagnosis report provided by Huang Yu, so that the treatment had a "target".

"At that time, the team of the Third Hospital of Beijing Medical University, in cooperation with Professor Xie Xiaoliang and Professor Tang Fuhui of Peking University, had developed the precision embryo diagnosis technology - MARSALA technology." Yan Liying introduced that the Third Hospital of Beijing Medical University implemented the "third generation" assisted reproductive technology for Tongtong's parents to conduct single-gene diagnosis before embryo implantation. After obtaining 9 embryos by ivory fertilization, laboratory staff carefully removed several cells from each embryo under a microscope with a glass needle thinner than a human hair, and performed genetic analysis by high-throughput sequencing.

Yan Liying said that the genetic analysis results showed that 3 embryos did not carry the disease-causing genes of either parent, but two of the embryos had abnormalities in their chromosomes, and only embryo No. 5 was most suitable for transfer.

In 2016, with the help of preimplantation embryo genetics diagnostic technology of the Third Hospital of Beijing Medical College, Tong Tong's younger brother Da Zhuang was born.

DaZhuang's birth also brought hope to Tong Tong's treatment. According to reports, the Department of Hematology of the Third Hospital of Beijing Medical University tried to use mesenchymal stem cells isolated from the placenta to carry out 5 stem cell transplant treatments for Tongtong, which alleviated Tongtong's condition to a certain extent, but the technology is still in the clinical exploration stage.

Tongtong's mother, Ms. Hu, said that the care and help of the Third Hospital of Beijing Medical University for many years has given the whole family confidence and courage, and the continuous exploration of new technologies has not only ushered in a healthy and strong family, but also brought more hope for Tongtong's survival.