title: Retrospective diagnosis of feline GM2 gangliosidosis variant 0 (Sandhoff-like disease) in Japan: possible spread of the mutant allele in the Japanese domestic cat population.
abstract: GM2 gangliosidosis variant 0 (human Sandhoff disease) is a lysosomal storage disease caused by simultaneous deficiencies of acid beta-hexosaminidase (Hex) A and Hex B due to an abnormality of beta-subunit, a common component in these enzyme molecules, which is coded by the HEXB gene. In the present study, a retrospective diagnosis was performed in 2 previous suspected cases of feline Sandhoff-like disease using a DNA test to detect the causative mutation identified previously in 4 cats in 2 other families of Japanese domestic cats. Enzymic analysis was also performed using stored leukocytes and plasma collected from the subject families in order to investigate the usefulness of enzymic diagnosis and genotyping of carriers. The DNA test suggested that the 2 cases were homozygous recessive for the mutation. Consequently, 6 cats homozygous for the same mutation have been found in 4 separate locations of Japan, suggesting that this mutant allele may be spread widely in the Japanese domestic cat populations. In enzymic analysis, Hex A and Hex B activities in leukocytes and plasma measured using 4-methylumbelliferyl N-acetyl-beta-D-glucosaminide as a substrate were negligible in affected cats, compared with those in normal and carrier cats. However, there was a wide overlap in enzyme activity between normal and carrier cats. Therefore, it was concluded that enzymic analysis is useful for diagnosis of affected cats, but is not acceptable for genotyping of carriers.
authors.affiliation: Laboratory of Clinical Pathology, Department of Veterinary Clinical Sciences, Faculty of Agriculture, Kagoshima University, Kagoshima, Japan. osam@agri.kagoshima-u.ac.jp
authors.forename: Osamu
authors.initials: O
authors.lastname: Yamato
authors.forename: Daisuke
authors.initials: D
authors.lastname: Hayashi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Satoh
authors.forename: Toru
authors.initials: T
authors.lastname: Shoda
authors.forename: Keiko
authors.initials: K
authors.lastname: Uchida
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakayama
authors.forename: Hiroki
authors.initials: H
authors.lastname: Sakai
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Masegi
authors.forename: Atsuko
authors.initials: A
authors.lastname: Murai
authors.forename: Tsuneyoshi
authors.initials: T
authors.lastname: Iida
authors.forename: Hiromi
authors.initials: H
authors.lastname: Hisada
authors.forename: Atsunori
authors.initials: A
authors.lastname: Hisada
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yamasaki
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Maede
authors.forename: Toshiro
authors.initials: T
authors.lastname: Arai
mesh_terms: D000818:Animals; D000829:Animals, Domestic; D002353:Carrier State / Q000662:veterinary; D002371:Cat Diseases / Q000453:epidemiology / Q000235:genetics*; D002415:Cats; D020143:Gangliosidoses, GM2 / Q000453:epidemiology / Q000235:genetics / Q000662:veterinary*; D014644:Genetic Variation; D015994:Incidence; D007564:Japan; D012189:Retrospective Studies