title: Newly observed thalamic involvement and mutations of the HEXA gene in a Korean patient with juvenile GM2 gangliosidosis.
abstract: Neuroimaging studies of patients with GM2 gangliosidosis are rare. The thalamus and basal ganglia are principally involved in patients affected by the infantile form of GM2 gangliosidosis. Unlike in the infantile form, in juvenile or adult type GM2 gangliosidosis, progressive cortical and cerebellar atrophy is the main abnormality seen on conventional magnetic resonance imaging (MRI); no basal ganglial or thalamic impairment were observed. This report is of a Korean girl with subacute onset, severe deficiency of hexosaminidase A activity and mutations (Arg137Term, Ala246Thr) of the HEXA gene. A 3.5-year-old girl who was previously in good health was evaluated for hypotonia and ataxia 3 months ago and showed progressive developmental deterioration, including cognitive decline. Serial brain MRI showed progressive overall volume decrease of the entire brain and thalamic atrophy. Fluorine-18 FDG PET scan showed severe decreased uptake in bilateral thalamus and diffuse cerebral cortex. We suggest, through our experience, that the thalamic involvement in MR imaging and FDG-PET can be observed in the juvenile form of GM2 gangliosidosis, and we suspect the association of mutations in the HEXA gene.
authors.affiliation: Department of Pediatrics, Severance Children's Hospital, Yongdong Severance Hospital, Yonsei University College of Medicine, 612 Eonjuro (146-92 Dogok-dong), Gangnam-gu, Kangnam, P.O. Box 1217, Seoul, South Korea 135-720.
authors.forename: Soon Min
authors.initials: SM
authors.lastname: Lee
authors.forename: Min Jung
authors.initials: MJ
authors.lastname: Lee
authors.forename: Joon Soo
authors.initials: JS
authors.lastname: Lee
authors.forename: Heung Dong
authors.initials: HD
authors.lastname: Kim
authors.forename: Jin Sung
authors.initials: JS
authors.lastname: Lee
authors.forename: Jinna
authors.initials: J
authors.lastname: Kim
authors.forename: Seung Koo
authors.initials: SK
authors.lastname: Lee
authors.forename: Young Mock
authors.initials: YM
authors.lastname: Lee
mesh_terms: D001259:Ataxia / Q000209:etiology; D001921:Brain / Q000254:growth & development / Q000473:pathology; D002675:Child, Preschool; D004247:DNA / Q000235:genetics; D005091:Exons / Q000235:genetics; D005260:Female; D019788:Fluorodeoxyglucose F18; D020143:Gangliosidoses, GM2 / Q000000981:diagnostic imaging / Q000235:genetics* / Q000473:pathology*; D006801:Humans; D007723:Korea; D008279:Magnetic Resonance Imaging; D009123:Muscle Hypotonia / Q000209:etiology; D009154:Mutation / Q000502:physiology*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D013788:Thalamus / Q000000981:diagnostic imaging / Q000473:pathology*; D054820:beta-Hexosaminidase alpha Chain / Q000235:genetics*
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D004247:DNA; C518253:HEXA protein, human; D054820:beta-Hexosaminidase alpha Chain