Newborn Screening: Mucopolysaccharidosis type II — Newborn Screening Panel Nomination

Wisconsin health care providers can nominate a condition to add to the Wisconsin newborn screening panel. The panel is part of the Wisconsin Newborn Screening Program.

The purpose of this page is to show providers the nomination process for Mucopolysaccharidosis type II (MPS II).

What is MPS II?

Mucopolysaccharidosis type II (MPS II, also called Hunter syndrome) is an X-linked lysosomal disorder caused by a deficiency of iduronate-2-sulfatase (I2S) due to pathogenic variants in the iduronate-2-sulfatase (IDS) gene. As an X-linked disorder males are predominantly affected; few affected females have been reported in cases of skewed X-inactivation or X chromosome abnormalities. This enzymatic defect results in progressive accumulation of glycosaminoglycans (GAGs, also known as mucopolysaccharides), dermatan sulfate and heparan sulfate, in various body tissues, causing a multisystem disorder with highly variable age of onset, rate of progression, and disease severity. Primary clinical features include progressive airway disease, cardiac valvular disease, skeletal involvement, and central nervous system (CNS) involvement in the form of progressive cognitive decline.

MPS II is characterized clinically as “severe” or “attenuated” (previously “neuronopathic” and “non-neuronopathic”) depending on the presence or absence of neurological involvement. Approximately two-thirds of affected individuals have the severe form of MPS II. Other common features in both forms of MPS II include: short stature; macrocephaly with or without communicating hydrocephalus; macroglossia; hoarse voice; conductive and sensorineural hearing loss; hepatosplenomegaly; dysostosis multiplex; spinal stenosis; and carpal tunnel syndrome.” (Scarpa et al., GeneReviews). Treatment is available in the form of enzyme replacement therapy, but this treatment does not ameliorate the neurologic involvement in the severe form of MPS II). Therapeutic approaches for severe MPS II such as enzyme delivery to the central nervous system, or gene therapy are in development. Without treatment, individuals with the severe form typically live only into their second decade. Individuals with the attenuated form may live into their fifth or sixth decade. (Wraith et al., 2008)

Nomination process for MPS II

The following timeline outlines the newborn screening panel nomination process:

• The Wisconsin Newborn Screening Program received a nomination (PDF) submitted on March 26, 2025, to add MPS II to the newborn screening panel.
• The Metabolic Subcommittee considered the nomination during a meeting on April 11, 2025, and recommended adding MPS II to the Wisconsin newborn screening panel. The subcommittee forwarded their recommendation to the Umbrella Committee.
• The Newborn Screening Umbrella Committee considered the nomination during a meeting on May 2, 2025, and recommended adding MPS II to the newborn screening panel of conditions. The Umbrella Committee forwarded their recommendation to the Secretary's Advisory Committee on Newborn Screening (SACNBS).
• The Secretary’s Advisory Committee on Newborn Screening (SACNBS) considered the nomination on September 19, 2025, and forwarded a report (PDF) to the Secretary of the Department of Health Services in support of adding MPS II to the newborn screening panel of conditions.
• The Secretary approved the recommendation (PDF) to add MPS II to the newborn screening panel of conditions on February 17, 2026.

Learn more about Administrative rulemaking at DHS and the Wisconsin Legislature. If you have questions about the nomination process, contact the Newborn Screening Program at DHSNewbornScreening@dhs.wisconsin.gov.