Newborn screening for lysosomal storage disorders expanded in Korea

Korea has expanded its newborn screening program to include tests for lysosomal storage disorders (LSD), a group of rare genetic diseases that cause severe health problems.

Starting from Jan. 1, 2024, all newborns in Korea are screened for LSDs within 28 days of birth. This early screening will enable healthcare providers to identify enzyme deficiencies and begin discussions on appropriate treatment options immediately.

This initiative was explained in detail by medical experts from Seoul National University Hospital and Soonchunhyang University Hospital at a media seminar held by Sanofi on Tuesday.

LSDs are caused by enzyme deficiencies that lead to the accumulation of substances within cells, resulting in progressive and irreversible damage to various organs and tissues.

Prominent LSDs include Pompe disease, Mucopolysaccharidosis (MPS), Gaucher disease, and Fabry disease. These disorders manifest in various symptoms such as motor dysfunction, skeletal deformities, organ enlargement, and peripheral pain, making clinical diagnosis challenging.

Professor Chae Jong-hee of the Department of Pediatric Neurosurgery at Seoul National University Hospital emphasized the critical importance of early diagnosis and treatment.

"LSDs often begin in childhood and can cause irreversible damage if not treated promptly,” Chae said. “Early diagnosis through newborn screening and subsequent enzyme replacement therapy (ERT) can prevent the progression of symptoms and ensure normal growth and development.”

Professor Chae shared a compelling case of siblings diagnosed with mucopolysaccharidosis type I.

The older sibling, who began ERT at five years old, exhibited multiple skeletal deformities. In contrast, the younger sibling, diagnosed through newborn screening and treated from five months old, showed normal growth and no skeletal abnormalities.

"Initiating treatment by age ten is often too late, and even starting at six years old may not bring the child within the normal growth curve," Chae said. "Children who start treatment early show normal growth and skeletal development, underscoring the importance of early diagnosis and intervention."

Further emphasizing the critical nature of early treatment, Professor Chae noted, "For Pompe disease, untreated children face high mortality rates if not treated by age two.”

Early treatment results in an 85 percent survival rate with mild complications and starting treatment immediately after birth could potentially raise survival rates to over 90 percent, she added.

Professor Lee Jeong-ho of the Department of Pediatrics at Soonchunhyang University Hospital highlighted the need for increased awareness and education about LSDs.

"LSDs have been poorly understood, and patients often lack access to accurate information about their conditions,” Lee said “Expanding the newborn screening program is a significant step towards improving diagnosis rates and ensuring that newly diagnosed patients can promptly receive the care they need.”

Professor Lee introduced a survey from 2018, which showed that 1,705 patients in a rare disease support program revealed that 64.28 percent were diagnosed within a year of symptom onset, while 6.1 percent waited over ten years.

Additionally, 16.4 percent of patients visited four or more hospitals before receiving a final diagnosis.

"Given the systemic nature of LSDs, clinical diagnosis is challenging. Early treatment is crucial for a positive prognosis, making the recent inclusion of LSD screening in the newborn screening program a highly promising development," said Professor Lee.

The newborn screening program, which tests all newborns within 48 to 72 hours after birth for various genetic conditions, now includes six enzyme activity tests for LSDs.

This inclusion ensures early detection and intervention for newborns showing signs of lysosomal enzyme deficiencies.

Newborns flagged for enzyme abnormalities through newborn screening program are referred to specialized regional centers for precise diagnosis and treatment discussions.

Conditions registered under the rare and severe disease category are eligible for outpatient medical cost support under the first-class medical assistance program.

"Previously, low disease awareness limited patients' access to accurate treatment information,” Lee said. “The comprehensive implementation of newborn screening allows for early disease identification, facilitating prompt intervention.”

Public awareness and discussion about these conditions and their treatments are now more critical than ever, Lee added.

He also highlighted that Korea introduced newborn screening later than the U.S., Europe, Japan, and Taiwan, but has since made significant strides in expanding and improving the screening process.

"There is now a need for a government organization to manage the statistics of newborn screening results, including positive cases and confirmed diagnoses,” Lee said. “As medical technology advances and more treatable conditions are identified, the scope of newborn screening must rapidly expand.”