| Autor: |
Kagawa R; Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, Minami-ku, Hiroshima 734-8551, Japan., Tajima G; Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, Minami-ku, Hiroshima 734-8551, Japan.; Division of Neonatal Screening, Research Institute, National Center for Child Health and Development, Setagaya-ku, Tokyo 157-8535, Japan., Maeda T; Division of Neonatal Screening, Research Institute, National Center for Child Health and Development, Setagaya-ku, Tokyo 157-8535, Japan., Sakura F; Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, Minami-ku, Hiroshima 734-8551, Japan., Nakamura-Utsunomiya A; Department of Pediatrics, Hiroshima Prefectural Hospital, Minami-ku, Hiroshima 734-8530, Japan., Hara K; Department of Pediatrics, National Hospital Organization Kure Medical Center and Chugoku Cancete Center, Kure 737-0023, Japan., Nishimura Y; Department of General Perinatology, Hiroshima City Hiroshima Citizens Hospital, Naka-Ku, Hiroshima 730-8518, Japan., Yuasa M; Department of Pediatrics, Faculty of Medical Sciences, University of Fukui, Eiheiji-cho, Fukui 910-1193, Japan., Shigematsu Y; Department of Pediatrics, Faculty of Medical Sciences, University of Fukui, Eiheiji-cho, Fukui 910-1193, Japan., Tanaka H; Hiroshima City Medical Association Clinical Laboratory, Naka-ku, Hiroshima 730-8611, Japan., Fujihara S; Hiroshima City Medical Association Clinical Laboratory, Naka-ku, Hiroshima 730-8611, Japan., Yoshii C; Hiroshima City Medical Association Clinical Laboratory, Naka-ku, Hiroshima 730-8611, Japan., Okada S; Department of Pediatrics, Hiroshima University Graduate School of Biomedical and Health Sciences, Minami-ku, Hiroshima 734-8551, Japan. |
| Abstrakt: |
Neonatal screening (NS) for methylmalonic acidemia uses propionylcarnitine (C3) as a primary index, which is insufficiently sensitive at detecting methylmalonic acidemia caused by defects in the adenosylcobalamin synthesis pathway. Moreover, homocystinuria from cystathionine β-synthase deficiency is screened by detecting hypermethioninemia, but methionine levels decrease in homocystinuria caused by defects in homocysteine remethylation. To establish NS detection of methylmalonic acidemia and homocystinuria of these subtypes, we evaluated the utility of indices (1) C3 ≥ 3.6 μmol/L and C3/acetylcarnitine (C2) ≥ 0.23, (2) C3/methionine ≥ 0.25, and (3) methionine < 10 μmol/L, by retrospectively applying them to NS data of 59,207 newborns. We found positive results in 116 subjects for index (1), 37 for (2), and 15 for (3). Second-tier tests revealed that for index 1, methylmalonate (MMA) was elevated in two cases, and MMA and total homocysteine (tHcy) were elevated in two cases; for index 2 that MMA was elevated in one case; and for index 3 that tHcy was elevated in one case. Though data were anonymized, two cases identified by index 1 had been diagnosed with maternal vitamin B 12 deficiency during NS. Methylene tetrahydrofolate reductase deficiency was confirmed for the case identified by index 3, which was examined because an elder sibling was affected by the same disease. Based on these data, a prospective NS study is underway. |
