title: Periventricular heterotopia and white matter abnormalities in a girl with mosaic ring chromosome 6.
abstract: Ring chromosome 6 is a rare chromosome abnormality that arises typically de novo. The phenotypes can be highly variable, ranging from almost normal to severe malformations and neurological defects. We report a case of a 3-year-old girl with mosaic ring chromosome 6 who presented with being small for gestational age and intellectual disability, and whose brain MRI later revealed periventricular heterotopia and white matter abnormalities. Mosaicism was identified in peripheral blood cells examined by standard G-bands, mos 46,XX,r(6)(p25q27)[67]/45,XX,-6[25]/46,XX,dic r(6:6)(p25q27:p25q27)[6]/47,XX,r(6)(p25q27) × 2[2]. Using array-comparative genomic hybridization, we identified terminal deletion of 6q27 (1.5 Mb) and no deletion on 6p. To our knowledge, this is the first report of periventricular heterotopia and white matter abnormalities manifested in a patient with ring chromosome 6. These central nervous system malformations are further discussed in relation to molecular genetics.
authors.affiliation: Department of Pediatrics, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan.
authors.forename: Satsuki
authors.initials: S
authors.lastname: Nishigaki
authors.affiliation: Department of Pediatrics, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Hamazaki
authors.affiliation: Department of Pediatrics, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan.
authors.forename: Mika
authors.initials: M
authors.lastname: Saito
authors.affiliation: Institute for Integrated Medical Sciences, Tokyo Women's Medical University, 8-1 Kawada-cho, Shinjuku-ward, Tokyo, 162-8666 Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Department of Pediatrics, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Seto
authors.affiliation: Department of Pediatrics, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-ku, Osaka, 545-8585 Japan.
authors.forename: Haruo
authors.initials: H
authors.lastname: Shintaku
keywords: Array-comparative genomic hybridization; Brain MRI; Periventricular heterotopia; Ring chromosome 6; Small for gestational age; White matter abnormality