Arginine to ornithine ratio as a diagnostic marker in patients with positive newborn screening for hyperargininemia
| Autor: | Rossana Sanchez Russo, Charles M. Rowland, Chung Lee, Pranoot Tanpaiboon, Stephen D. Cederbaum, Inderneel Sahai, Denise Salazar, Derek Wong, Yue Huang, Felicitas Lacbawan, Rajesh Sharma, Juanita Neira, Susan Sklower Brooks, Annette Feigenbaum, Kelly E. Jackson |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Newborn screening
Ornithine Medicine (General) medicine.medical_specialty Arginine Arg/Orn arginine to ornithine ratio QH301-705.5 Endocrinology Diabetes and Metabolism Hyperargininemia Arg/Orn ratio Biochemistry DBS dry bloodspot 03 medical and health sciences chemistry.chemical_compound NBS newborn screening R5-920 0302 clinical medicine Endocrinology NBS Arginase deficiency Internal medicine Genetics medicine Biology (General) Molecular Biology Arg arginine 0303 health sciences business.industry 030305 genetics & heredity Hyperammonemia medicine.disease DOL day of life ROC receiver operating characteristic Arginase chemistry Inborn error of metabolism Urea cycle Orn ornithine business 030217 neurology & neurosurgery Research Paper |
| Zdroj: | Molecular Genetics and Metabolism Reports Molecular Genetics and Metabolism Reports, Vol 27, Iss, Pp 100735-(2021) |
| ISSN: | 2214-4269 |
| Popis: | Arginase deficiency is a rare inborn error of metabolism that interrupts the final step of the urea cycle. Untreated individuals often present with episodic hyperammonemia, developmental delay, cognitive impairment, and spasticity in early childhood. The newborn screening (NBS) algorithms for arginase deficiency vary between individual states in the US but often include hyperargininemia and elevated arginine to ornithine (Arg/Orn) ratio. Here, we report 14 arginase deficiency cases, including two patients with positive NBS for hyperargininemia in whom the diagnosis of arginase deficiency was delayed owing to normal or near normal plasma arginine levels on follow-up testing. To improve the detection capability for arginase deficiency, we evaluated plasma Arg/Orn ratio as a secondary diagnostic marker in positive NBS cases for hyperargininemia. We found that plasma Arg/Orn ratio combined with plasma arginine was a better marker than plasma arginine alone to differentiate patients with arginase deficiency from unaffected newborns. In fact, elevated plasma arginine in combination with an Arg/Orn ratio of ≥1.4 identified all 14 arginase deficiency cases. In addition, we examined the impact of age on plasma arginine and ornithine levels. Plasma arginine increased 0.94 μmol/L/day while ornithine was essentially unchanged in the first 31 days of life, which resulted in a similar increasing trend for the Arg/Orn ratio (0.01/day). This study demonstrated that plasma Arg/Orn ratio as a secondary diagnostic marker improved the detection capability for arginase deficiency in newborns with hyperargininemia, which will allow timely detection of arginase deficiency and hence initiation of treatment before developing symptoms. |
| Databáze: | OpenAIRE |
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