The first SMA child diagnosed through newborn genetic screening in China and treated before onset

2024-05-06   |  

A few days ago, Bei Bei's parents took Bei Bei to the Genetics and Metabolism Department of the Children's Hospital of Zhejiang University School of Medicine (ZCH) for a follow-up visit and expressed their heartfelt thanks to the medical team that diagnosed and treated their daughter. 

Bei Bei is a baby born in the spring of 2022. The arrival of their daughter filled the young parents with great happiness. After Bei Bei was born, besides routine newborn screening collecting three drops of blood from the heel, the young couple voluntarily participated in a newborn screening study for genetic diseases led by ZCH. 

What they did not expect was that their choice could save their child. After the screening was done, the results came back suggesting that Bei Bei was very likely to have spinal muscular atrophy (SMA).

SMA is an autosomal recessive disorder caused by motor neuron survival gene 1 (SMN1) mutation and can result in muscle weakness and muscular atrophy characterized by neuromuscular disease. SMA patients can show symptoms of hypotonia, significantly slow motor development, and being unable to walk independently. It can even be life-threatening, with a high possibility of disability and fatality. As one of the deadliest genetic diseases among infants under the age of two, SMA was included in China's First National List of Rare Diseases released by the National Health Commission in 2018.

At first, Bei Bei’s parents couldn't believe that their lovely daughter had this rare disease. They immediately took their daughter to the Genetics and Metabolism Department of ZCH for further diagnosis and treatment. Unfortunately, it was confirmed that Bei Bei is a child with SMA after a series of genetic tests. If the patient with SMA is not treated in time, it is likely to progress within 6-18 months, resulting in abnormal neuromuscular development, and even death in some cases. 

People start to wonder why normal parents can have children with a genetic disease. YANG Xin, deputy director of the Genetics and Metabolism Department, said, In China, about 1 out of 50 people are SMA gene carriers. Carriers do not show symptoms, but if both the husband and wife are carriers, their children have one in four chance to be SMA patients. 

As a child with a rare disease, Bei Bei is undoubtedly unfortunate, but fortunately, she conducted newborn genetic screening after birth and was diagnosed with the disease very early before the symptoms manifested.

We started the neonatal genetic screening program in 2022. Bei Bei was admitted to the program in its research stage before widespread clinical promotion, so she was the first child diagnosed with SMA through newborn genetic screening and also the first child with SMA in China to be treated with specific drugs before the disease onset, YANG Xin said.

Thanks to the joint efforts of experts from the Genetics and Metabolism Department and Neurology Department of ZCH and Bei Bei’s parents, Bei Bei has been receiving Nosinasan sodium injection treatment since she was less than 2 months old.

The effect of the treatment is beyond imagination. Now she is two years old, she grows up in the same way as other children of the same age. 

YANG Xin introduced that the consensus has been reached among experts that the earlier SMA drugs are used, the better the prognosis will be. Therefore, pre-symptomatic diagnosis and disease-modifying therapy can produce better outcomes, allowing affected children to live healthier lives.

Thanks to the specialists of ZCH and advanced newborn screening technologies, Bei Bei was diagnosed with the disease before symptoms manifested and received targeted treatment as soon as possible. Watching Bei Bei grow so well, Bei Bei’s parents feel very lucky and grateful.

Dr. YANG Rulai, director of the Genetics and Metabolism Department of ZCH, introduced the newborn genetic screening program, which refers to the genetic sequencing of heel blood after the birth of the newborn to predict the risk of some monogenic diseases with relatively high incidence. It can be seen as a new application of next-generation sequencing technology in the field of neonatal disease screening.

The current neonatal disease screening system of ZCH, as the tertiary prevention and control system of social health, has played an important role in the prevention and control of birth defects. Relying on the strong clinical research capability of ZCH, the Zhejiang Neonatal Disease Screening Center is responsible for the disease screening and management of newborns in Zhejiang Province.

Professor SHU Qiang, director of Zhejiang Neonatal Disease Screening Center, introduced that ZCH took the lead in the research and exploration of newborn gene screening in China, and demonstrated the application significance of newborn screening in the field of tertiary prevention and control of birth defects through research among multiple centers in the country. Newborn disease screening has become one of the most successful public health policies in China. Zhejiang Neonatal Disease Screening Center started the newborn screening work in 1999 and has screened more than 12 million newborns so far, and the screening rate reaches more than 99.9%. A total of more than 20,000 children were diagnosed (9503 cases of congenital hypothyroidism, 591 cases of phenylketonuria/ tetrahydrobiopterin deficiency, 215 cases of congenital adrenal hyperplasia, 9979 cases of glucose-6-phosphate dehydrogenase deficiency, 1256 cases of amino acid, fatty acid, and organic acid metabolism disorders). The risk of death and disability caused by genetic metabolic diseases has been greatly reduced.

Professor SHU Qiang said, “It is hoped that through the clinical application of neonatal genetic screening, more neonatal diseases will be screened. At the same time, birth defect prevention and treatment will be improved. The successful experience of neonatal genetic metabolic disease screening will be applied to more rare diseases so that children like Bei Bei can be diagnosed and treated early.”

Doctors at the Genetics and Metabolism Department

Source: Children's Hospital of Zhejiang University School of Medicine