A diagnostic algorithm of newborn screening for elevated citrulline

Newborn screening of some urea cycle disorders has little benefits because of early severe symptoms before the result, low sensitivity (especially hypocitrullinemia) and poor prognosis. But in case of citrullinemia, citrin deficiency and argininosuccinic aciduria diagnosed as elevated citrulline, newborn screening is helpful for early diagnosis and treatment before the symptom. Distinction between the clinical forms of these diseases is based on clinical findings and biochemical results, however, they may not be clearcut. Treatment is different from each other, so exact diagnosis is essential. Here, the diagnostic algorithm for elevated citrulline after tandem mass screening has been proposed. Minimizing total process time from sampling to report of the results is important in Korea for diagnosis and treatment of these disorders.ope