October 2025: Homocystinuria Awareness Month

WHEREAS, homocystinuria (HCU) is characterized by elevated levels of the amino acid homocysteine, one of the building blocks of protein produced in the body; and,

WHEREAS, HCU is a rare inherited metabolic disorder that impairs the body’s ability to process the amino acid methionine, leading to the buildup of homocysteine and other harmful compounds. Classical HCU, cobalamin C deficiency, and severe methylenetetrahydrofolate reductase (MTHFR) deficiency are the most common forms of homocystinuria; and,

WHEREAS, HCU can cause serious health issues, including developmental delays, vision problems, osteoporosis, vascular disease and blood clots, and other complications if not detected and treated early; and,

WHEREAS, classical HCU was officially added to the Recommended Uniform Screening Panel (RUSP) in 2009 and is now screened for in every state at birth. Newborn screening for methylmalonic acidemia, also a RUSP condition, will identify HCU caused by cobalamin A and B deficiency, and may sometimes pick up other cobalamin subtypes; and,

WHEREAS, early diagnosis through newborn screening and effective management strategies can greatly enhance the health and quality of life for individuals affected by HCU; and,

WHEREAS, some babies with classical HCU may be missed by current newborn screening strategies, highlighting an urgent need for improvements; and,

WHEREAS, HCU affects approximately 1 in 100,000-200,000 individuals in the United States; however, this figure is likely an underestimate, as multiple studies indicate the actual birth prevalence may be considerably higher due to underdiagnosis and limitations in current newborn screening methods; and,

WHEREAS, HCU Network America collaborates with state newborn screening laboratories, policymakers, healthcare providers, patient organizations, and innovative, research-driven industry partners to address these gaps, improve screening protocols, and ensure early detection and treatment of all affected individuals in Michigan; and,

WHEREAS, designating October as “Homocystinuria Awareness Month” will boost efforts to improve the lives of those affected by all types of homocystinuria and advance progress toward earlier diagnosis, better treatments, and ultimately, a cure.

NOW, THEREFORE, I, Gretchen Whitmer, governor of Michigan, do hereby proclaim October 2025, as Homocystinuria Awareness Month in Michigan.