{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,29]],"date-time":"2026-10-29T00:45:37Z","timestamp":1793234737186,"version":"4.5.0"},"reference-count":37,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2020,5,29]],"date-time":"2020-05-29T00:00:00Z","timestamp":1590710400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001700","name":"Ministry of Education, Culture, Sports, Science and Technology","doi-asserted-by":"publisher","award":["20K08197"],"award-info":[{"award-number":["20K08197"]}],"id":[{"id":"10.13039\/501100001700","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJNS"],"abstract":"<jats:p>Spinal muscular atrophy (SMA) is a common neuromuscular disease with autosomal recessive inheritance. The disease gene, SMN1, is homozygously deleted in 95% of SMA patients. Although SMA has been an incurable disease, treatment in infancy with newly developed drugs has dramatically improved the disease severity. Thus, there is a strong rationale for newborn and carrier screening for SMA, although implementing SMA carrier screening in the general population is controversial. We previously developed a simple, accurate newborn SMA screening system to detect homozygous SMN1 deletions using dried blood spots (DBS) on filter paper. Here, we modified our previous system to detect the heterozygous deletions of SMN1, which indicates SMA carrier status. The system involves a calibrator-normalized relative quantification method using quantitative nested PCR technology. Our system clearly separated the DBS samples with one SMN1 copy (carrier status with a heterozygous deletion of SMN1) from the DBS samples with two SMN1 copies (non-carrier status with no deletion of SMN1). We also analyzed DBS samples from SMA families, confirmed SMA in the affected children, and determined the carrier status of their parents based on the SMN1 copy number. In conclusion, our system will provide essential information for risk assessment and genetic counseling, at least for SMA families.<\/jats:p>","DOI":"10.3390\/ijns6020043","type":"journal-article","created":{"date-parts":[[2020,6,1]],"date-time":"2020-06-01T11:49:21Z","timestamp":1591012161000},"page":"43","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":13,"title":["Assessment of Spinal Muscular Atrophy Carrier Status by Determining SMN1 Copy Number Using Dried Blood Spots"],"prefix":"10.3390","volume":"6","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8066-9211","authenticated-orcid":false,"given":"Yogik Onky Silvana","family":"Wijaya","sequence":"first","affiliation":[{"name":"Department of Community Medicine and Social Healthcare Science, Division of Epidemiology, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jamiyan","family":"Purevsuren","sequence":"additional","affiliation":[{"name":"Medical Genetics Laboratory, National Center for Maternal and Child Health, Khuvisgalchdyn Street, Bayangol District, Ulaanbaatar 16060, Mongolia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nur Imma Fatimah","family":"Harahap","sequence":"additional","affiliation":[{"name":"Department of Clinical Pathology and Laboratory Medicine, Faculty of Medicine, Universitas Gadjah Mada, Radiopoetro Building 5th floor, Jl. Farmako, Sekip Utara, Yogyakarta 55281, Indonesia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1311-3448","authenticated-orcid":false,"given":"Emma Tabe Eko","family":"Niba","sequence":"additional","affiliation":[{"name":"Department of Community Medicine and Social Healthcare Science, Division of Epidemiology, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yoshihiro","family":"Bouike","sequence":"additional","affiliation":[{"name":"Faculty of Nutrition, Kobe Gakuin University, 518 Arise, Ikawadani-cho, Nishi-ku, Kobe 651-2180, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dian Kesumapramudya","family":"Nurputra","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, Faculty of Medicine, Universitas Gadjah Mada, Jl. Kesehatan No.1, Sekip, Yogyakarta 55281, Indonesia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mawaddah Ar","family":"Rochmah","sequence":"additional","affiliation":[{"name":"Department of Neurology, Faculty of Medicine, Universitas Gadjah Mada, Jl. Kesehatan No.1, Sekip, Yogyakarta 55281, Indonesia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cempaka","family":"Thursina","sequence":"additional","affiliation":[{"name":"Department of Neurology, Faculty of Medicine, Universitas Gadjah Mada, Jl. Kesehatan No.1, Sekip, Yogyakarta 55281, Indonesia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sunartini","family":"Hapsara","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, Faculty of Medicine, Universitas Gadjah Mada, Jl. Kesehatan No.1, Sekip, Yogyakarta 55281, Indonesia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Seiji","family":"Yamaguchi","sequence":"additional","affiliation":[{"name":"Department of Pediatrics, Shimane University School of Medicine, 89-1 Enya, Izumo, Shimane 693-8501, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6778-4511","authenticated-orcid":false,"given":"Hisahide","family":"Nishio","sequence":"additional","affiliation":[{"name":"Department of Community Medicine and Social Healthcare Science, Division of Epidemiology, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan"},{"name":"Faculty of Rehabilitation, Kobe Gakuin University, 518 Arise, Ikawadani-cho, Nishi-ku, Kobe 651-2180, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Masakazu","family":"Shinohara","sequence":"additional","affiliation":[{"name":"Department of Community Medicine and Social Healthcare Science, Division of Epidemiology, Kobe University Graduate School of Medicine, 7-5-1 Kusunoki-cho, Chuo-ku, Kobe 650-0017, Japan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,5,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"435","DOI":"10.1111\/ahg.12031","article-title":"Spinal muscular atrophy: From gene discovery to clinical trials","volume":"77","author":"Nurputra","year":"2013","journal-title":"Ann. Hum. Genet."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1016\/0092-8674(95)90460-3","article-title":"Identification and characterization of a spinal muscular atrophy-determining gene","volume":"80","author":"Lefebvre","year":"1995","journal-title":"Cell"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"228","DOI":"10.1002\/(SICI)1098-1004(200003)15:3<228::AID-HUMU3>3.0.CO;2-9","article-title":"An update of the mutation spectrum of the survival motor neuron gene (SMN1) in autosomal recessive spinal muscular atrophy (SMA)","volume":"15","author":"Wirth","year":"2000","journal-title":"Hum. Mutat."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1002\/mus.24497","article-title":"Spinal muscular atrophy: Diagnosis and management in a new therapeutic era","volume":"51","author":"Arnold","year":"2014","journal-title":"Muscle Nerve"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1723","DOI":"10.1056\/NEJMoa1702752","article-title":"Nusinersen versus sham control in Infantile-Onset spinal muscular atrophy","volume":"377","author":"Finkel","year":"2017","journal-title":"N. Engl. J. Med."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1713","DOI":"10.1056\/NEJMoa1706198","article-title":"Single-Dose Gene-Replacement therapy for spinal muscular atrophy","volume":"377","author":"Mendell","year":"2017","journal-title":"N. Engl. J. Med."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"842","DOI":"10.1016\/j.nmd.2019.09.007","article-title":"Nusinersen initiated in infants during the presymptomatic stage of spinal muscular atrophy: Interim efficacy and safety results from the Phase 2 NURTURE study","volume":"29","author":"Bertini","year":"2019","journal-title":"Neuromuscul. Disord."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"840","DOI":"10.1097\/GIM.0b013e318188d069","article-title":"Carrier screening for spinal muscular atrophy","volume":"10","author":"Prior","year":"2008","journal-title":"Genet. Med."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1608","DOI":"10.1002\/ajmg.a.33474","article-title":"Newborn and carrier screening for spinal muscular atrophy","volume":"152","author":"Prior","year":"2010","journal-title":"Am. J. Med Genet. Part A"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"124","DOI":"10.1016\/j.jpeds.2017.06.042","article-title":"Presymptomatic diagnosis of spinal muscular atrophy through newborn screening","volume":"190","author":"Chien","year":"2017","journal-title":"J. Pediatr."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"608","DOI":"10.1038\/gim.2017.152","article-title":"Pilot study of Population-Based newborn screening for spinal muscular atrophy in New York state","volume":"20","author":"Kraszewski","year":"2017","journal-title":"Genet. Med."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"23","DOI":"10.1038\/s41431-019-0476-4","article-title":"High-Throughput genetic newborn screening for spinal muscular atrophy by rapid nucleic acid extraction from dried blood spots and 384-Well qPCR","volume":"28","author":"Czibere","year":"2019","journal-title":"Eur. J. Hum. Genet."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Shinohara, M., Niba, E.T.E., Wijaya, Y.O.S., Takayama, I., Mitsuishi, C., Kumasaka, S., Kondo, Y., Takatera, A., Hokuto, I., and Morioka, I. (2019). A novel system for spinal muscular atrophy screening in newborns: Japanese pilot study. Int. J. Neonatal Screen., 5.","DOI":"10.3390\/ijns5040041"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"503","DOI":"10.3233\/JND-190428","article-title":"One year of newborn screening for SMA-Results of a german pilot project","volume":"6","author":"Vill","year":"2019","journal-title":"J. Neuromuscul. Dis."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"253.e1","DOI":"10.1016\/j.ajog.2010.01.032","article-title":"The Cost-Effectiveness of prenatal screening for spinal muscular atrophy","volume":"202","author":"Little","year":"2010","journal-title":"Am. J. Obstet. Gynecol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"551","DOI":"10.1016\/j.nmd.2016.06.459","article-title":"Opening the window: The case for carrier and perinatal screening for spinal muscular atrophy","volume":"26","author":"Burns","year":"2016","journal-title":"Neuromuscul. Disord."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"346","DOI":"10.1111\/j.1442-200X.2008.02590.x","article-title":"SMN2 and NAIP gene dosages in Vietnamese patients with spinal muscular atrophy","volume":"50","author":"Tran","year":"2008","journal-title":"Pediatr. Int."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"774","DOI":"10.1016\/j.braindev.2017.04.015","article-title":"Genetic screening of spinal muscular atrophy using a Real-Time modified COP-PCR technique with dried Blood-Spot DNA","volume":"39","author":"Rochmah","year":"2017","journal-title":"Brain Dev."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1411","DOI":"10.1086\/515465","article-title":"Identification of proximal spinal muscular atrophy carriers and patients by analysis of SMNT and SMNC gene copy number","volume":"60","author":"McAndrew","year":"1997","journal-title":"Am. J. Hum. Genet."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"609","DOI":"10.1007\/s10545-007-0622-y","article-title":"First ISNS reference preparation for neonatal screening for thyrotropin, phenylalanine and 17\u03b1-hydroxyprogesterone in blood spots","volume":"30","author":"Elvers","year":"2007","journal-title":"J. Inherit. Metab. Dis."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1438","DOI":"10.1111\/j.1365-2672.2008.04119.x","article-title":"A nested Real-Time PCR assay has an increased sensitivity suitable for detection of viruses in aerosol studies","volume":"106","author":"Perrott","year":"2009","journal-title":"J. Appl. Microbiol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"393","DOI":"10.1186\/1475-2875-13-393","article-title":"A nested Real-Time PCR assay for the quantification of Plasmodium falciparum DNA extracted from dried blood spots","volume":"13","author":"Tran","year":"2014","journal-title":"Malar. J."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"37","DOI":"10.1089\/gtmb.2008.0084","article-title":"A simple multiplex Real-Time PCR methodology for the SMN1 gene copy number quantification","volume":"13","author":"Passon","year":"2009","journal-title":"Genet. Test. Mol. Biomark."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1211","DOI":"10.1007\/s00415-002-0811-4","article-title":"Correlation between SMN2 copy number and clinical phenotype of spinal muscular atrophy: Three SMN2 copies fail to rescue some patients from the disease severity","volume":"249","author":"Harada","year":"2002","journal-title":"J. Neurol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"74","DOI":"10.1002\/humu.10221","article-title":"Determination of SMN1 and SMN2 Copy Number Using TaqManTM Technology","volume":"22","author":"Anhuf","year":"2003","journal-title":"Hum. Mutat."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"88","DOI":"10.1016\/j.clinbiochem.2011.10.019","article-title":"Spinal muscular atrophy: Clinical validation of a Single-Tube multiplex real time PCR assay for determination of SMN1 and SMN2 copy numbers","volume":"45","author":"Maranda","year":"2012","journal-title":"Clin. Biochem."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"428","DOI":"10.1097\/01.gim.0000227970.60450.b2","article-title":"A feasibility study for the newborn screening of spinal muscular atrophy","volume":"8","author":"Prior","year":"2006","journal-title":"Genet. Med."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"412","DOI":"10.1373\/clinchem.2014.231019","article-title":"Newborn Blood Spot Screening Test Using Multiplexed Real-Time PCR to simultaneously screen for spinal muscular atrophy and severe combined immunodeficiency","volume":"61","author":"Taylor","year":"2015","journal-title":"Clin. Chem."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Strunk, A., Abbes, A., Stuitje, A.R., Hettinga, C., Sepers, E.M., Snetselaar, R., Schouten, J., Asselman, F.-L., Cuppen, I., and Lemmink, H. (2019). Validation of a Fast, Robust, Inexpensive, Two-Tiered neonatal screening test algorithm on dried blood spots for spinal muscular atrophy. Int. J. Neonatal Screen., 5.","DOI":"10.3390\/ijns5020021"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"111","DOI":"10.4236\/ojgen.2013.32014","article-title":"1000 sample comparison of MLPA and RT-PCR for carrier detection and diagnostic testing for spinal muscular atrophy type 1","volume":"3","author":"Strom","year":"2013","journal-title":"Open J. Genet."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"343","DOI":"10.1016\/j.nmd.2019.02.003","article-title":"Newborn screening for SMA in Southern Belgium","volume":"29","author":"Boemer","year":"2019","journal-title":"Neuromuscul. Disord."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"851","DOI":"10.1016\/j.braindev.2017.06.002","article-title":"Spinal muscular atrophy carriers with two SMN1 copies","volume":"39","author":"Rochmah","year":"2017","journal-title":"Brain Dev."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"72","DOI":"10.1007\/s10897-016-9980-7","article-title":"Notable carrier risks for individuals having two copies of SMN1 in spinal muscular atrophy families with 2-Copy Alleles: Estimation based on chinese meta-analysis data","volume":"26","author":"Wei","year":"2016","journal-title":"J. Genet. Couns."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1596","DOI":"10.1086\/340789","article-title":"SMN dosage analysis and risk assessment for spinal muscular atrophy","volume":"70","author":"Ogino","year":"2002","journal-title":"Am. J. Hum. Genet."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1038\/gim.2013.84","article-title":"An ashkenazi jewish SMN1 haplotype specific to duplication alleles improves Pan-Ethnic carrier screening for spinal muscular atrophy","volume":"16","author":"Luo","year":"2013","journal-title":"Genet. Med."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"1554","DOI":"10.1038\/s41431-018-0193-4","article-title":"Utility of two SMN1 variants to improve spinal muscular atrophy carrier diagnosis and genetic counselling","volume":"26","author":"Bernal","year":"2018","journal-title":"Eur. J. Hum. Genet."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"93","DOI":"10.1016\/j.nmd.2019.11.002","article-title":"244th ENMC international workshop: Newborn screening in spinal muscular atrophy May 10\u201312, 2019, Hoofdorp, The Netherlands","volume":"30","author":"Dangouloff","year":"2020","journal-title":"Neuromuscul. Disord."}],"container-title":["International Journal of Neonatal Screening"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2409-515X\/6\/2\/43\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T09:33:52Z","timestamp":1760175232000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2409-515X\/6\/2\/43"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,5,29]]},"references-count":37,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2020,6]]}},"alternative-id":["ijns6020043"],"URL":"https:\/\/doi.org\/10.3390\/ijns6020043","relation":{},"ISSN":["2409-515X"],"issn-type":[{"value":"2409-515X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,5,29]]}}}