The New York State Newborn Screening Program at the Wadsworth Center has become the first program in the United States to implement universal newborn screening for Metachromatic Leukodystrophy (MLD), a devastating but now treatable lysosomal storage disorder. MLD is caused by low or absent activity of the arylsulfatase A (ARSA) enzyme, leading to toxic accumulation of sulfatides and progressive damage to the nervous system. The late-infantile form is the most common and severe, with symptoms typically appearing between 6 months and 2 years of age. Children with this form often die within five to six years of diagnosis. Until recently, treatment options were limited and largely supportive. In March 2024, the FDA approved Lenmeldy (atidarsagene autotemcel), the first gene therapy for MLD. Lenmeldy significantly extends life expectancy and reduces cognitive and physical decline—but only when given in the pre-symptomatic or early symptomatic phase. Because the disease progresses rapidly, newborn screening is critical to ensure timely diagnosis and access to treatment.
Drawing on prior experience with MLD screening through the ScreenPlus pilot study, Wadsworth launched a universal pilot program on September 12, 2025. The condition has been provisionally added to the New York State screening panel for one year. MLD is not currently screened anywhere else in the U.S., but other states are expected to follow. At the federal level, HRSA is actively reviewing evidence and public comments to determine if MLD should be added to the Recommended Uniform Screening Panel (RUSP). Screening is performed by the Newborn Screening Program’s Lysosomal Lab using mass spectrometry to measure sulfatides, with enzyme activity and genetic testing used for confirmatory analysis. Infants with positive results will be referred to one of nine accredited specialty care centers in New York State for diagnostic confirmation and treatment planning.
The incidence of MLD is estimated at 1 in 40,000 to 1 in 170,000 births. New York expects to identify 1–5 affected newborns annually. At the conclusion of the pilot (FY 2026–2027), the program will recommend full addition of MLD to the mandated NYS newborn screening panel. This pioneering pilot study is funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and positions New York as a national leader in expanding access to life-saving newborn screening.