Technology ID

Multiplexing Homocysteine in Primary Newborn Screening Assays Using Maleimides as Select Derivatization Agents

Lead Inventor
Petritis, Konstantinos (CDC)
Pickens, Charles (CDC)
Research Materials
Occupational Safety and Health
Consumer Products
Therapeutic Areas
Infectious Disease
Development Stages
Research Products
Research Equipment
Lead IC
Homocystinuria (HCU), a group of inherited disorders, causes symptoms ranging from failure to thrive and developmental delays in infants or young children to abnormal blood clots with onset in adults.1 Approximately 1 in 200,000 to 335,000 people have HCU globally.2

Various clinical settings use the dried blood spot (DBS) for sample collection methods such as newborn screening tests for HCU. Due to the complex chemistry of homocysteine (Hcy), which is elevated in people with HCU, and known interferences, labs cannot screen DBS for this biomarker in primary-tier newborn screening assays. Instead, labs use methionine as a surrogate marker for dysfunction in the Hcy metabolic pathway, although methionine has poor sensitivity and specificity for HCU. This impacts false positive rates, causing parental anxiety and unnecessary burden for follow up teams, and false negative rates which increase the morbidity and mortality of newborns with HCU. There are reports of HCU cases having been missed.3 Another approach uses second-tier screening following the primary assay to test presumed positive specimens with elevated methionine for Hcy after a chromatographic separation step. This also has disadvantages in that specimens may not exceed the methionine cutoff to receive second-tier screening and added time (+1-5 days) before referral affects treatment delivery.

CDC has developed a workflow to selectively convert Hcy to a derivative using a maleimide reagent in a sample matrix. The process allows accurate quantification by shifting Hcy’s mass, thus, removing any undesired interferences. The specific derivative agent, N-ethylmaleimide, is widely available and has a very low price. CDC’s method screens Hcy during primary newborn screening from the DBS, along with dozens of other newborn screening biomarkers without adding substantial time or efforts to the screening process. No currently reported methods use this workflow to screen for Hcy in DBS. Current commercial products cannot screen for Hcy from DBS in areas of newborn screening and other clinical sciences that desire to quantify Hcy as a biomarker. This technology can potentially revolutionize HCU screening via DBS in newborns globally. DBS is also becoming more widely adopted as a sample collection method in other clinical areas. Eventually, clinical labs may begin to screen Hcy as a risk for cardiometabolic diseases/disorders and can benefit from the new workflow. CDC has demonstrated the workflow in DBS from HCU positive, presumptive normal, and those with reported administration of total parenteral nutrition.

  • 1.
  • 2.
  • 3. Bowron et al. Clinical Chemistry. 51, No.1, 2005.
Commercial Applications
  • DBS screening test kits for homocystinuria in newborn primary screening
  • DBS or blood sample screening test kit identifying Hcy as a biomarker for detecting heart disease, vitamin B12, vitamin B6, or folate deficiencies, diabetes, cancer, neurodegenerative diseases, etc.
  • Monitoring/public health surveillance
  • Quality control/quality assurance
  • Research tool
Competitive Advantages
  • Allows detection of Hcy in first-tier newborn screening in DBS with higher precision and does not affect other biomarkers co-analyzed in newborn DBS screening
  • Improved HCU screening sensitivity and specificity - with reduced false negative and false positive results over current methods
  • Workflow does not add significant time to the total assay preparation and added reagents are low cost and widely available
  • New method uses lower proportions of water (i.e., 20%) and allows for faster sample drying and cleaner flow injection analysis (FIA) injection ports in-turn
  • Readily adaptable to existing DBS screening kits or new screening test kit format
  • Avoids the need for additional specimen (urine or blood) collection while saving time, cost, and mental burden on parents
  • Enables healthcare providers to deliver needed treatment sooner at very early stages without the delay of second-tier screening
Licensing Contact:
Motley, Jonathan