title: Newborn screening for Pompe disease in Japan.
abstract: Pompe disease is caused by a deficiency of acid alpha-glucosidase (GAA) that results in glycogen accumulation, primarily in muscle. Newborn screening (NBS) for Pompe disease has been initiated in Taiwan and is reportedly successful. However, the comparatively high frequency of pseudodeficiency allele makes NBS for Pompe disease complicated in Taiwan. To investigate the feasibility of NBS for Pompe disease in Japan, we obtained dried blood spots (DBSs) from 496 healthy Japanese controls, 29 Japanese patients with Pompe disease, and five obligate carriers, and assayed GAA activity under the following conditions: (1) total GAA measured at pH 3.8, (2) GAA measured at pH 3.8 in the presence of acarbose, and (3) neutral glucosidase activity (NAG) measured at pH 7.0 without acarbose. The % inhibition and NAG/GAA ratio were calculated. For screening, samples with GAA<8% of the normal mean, % inhibition>60%, and NAG/GAA ratio>30 were considered to be positive. Two false positive cases (0.3%) were found, one was a healthy homozygote of pseudodeficiency allele (c.1726G>A). The low false-positive rate suggests that NBS for Pompe disease is feasible in Japan.
authors.affiliation: Department of Laboratory Medicine, National Center for Child Health and Development, Tokyo, Japan.
authors.forename: Eri
authors.initials: E
authors.lastname: Oda
authors.forename: Toju
authors.initials: T
authors.lastname: Tanaka
authors.forename: Ohsuke
authors.initials: O
authors.lastname: Migita
authors.forename: Motomichi
authors.initials: M
authors.lastname: Kosuga
authors.forename: Masaru
authors.initials: M
authors.lastname: Fukushi
authors.forename: Toshika
authors.initials: T
authors.lastname: Okumiya
authors.forename: Makiko
authors.initials: M
authors.lastname: Osawa
authors.forename: Torayuki
authors.initials: T
authors.lastname: Okuyama
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D059788:Dried Blood Spot Testing; D057075:Enzyme Assays; D005787:Gene Frequency; D006009:Glycogen Storage Disease Type II / Q000175:diagnosis*; D006579:Heterozygote; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007564:Japan; D008875:Middle Aged; D015997:Neonatal Screening; D012016:Reference Values; D055815:Young Adult; D000520:alpha-Glucosidases / Q000097:blood
chemical_list: C509951:GAA protein, human; D000520:alpha-Glucosidases