Inherited ring chromosome 8 without loss of subtelomeric sequences.
We report the first case of inherited ring chromosome 8 syndrome without loss of subtelomeric sequences. The proband is a 6 1/2-year-old boy with short stature, microcephaly, mild mental retardation, and behavioral problems including hyperactivity and attention deficit. His mother presented the same physical features but intelligence was normal. Family history also revealed an uncle and a grandmother, with short stature and microcephaly. Moderate mental retardation was reported in the uncle. Karyotypes and fluorescence in situ hybridization (FISH) analyses were performed on peripheral blood lymphocytes for both child and mother. The child's karyotype was reported as 46,XY,r(8)(p23q24.3)[24]/45,XY,-8[2] and the mother's karyotype 46,XX,r(8)(p23q24.3)[22]/45,XX,-8[2]/47,XX,r(8)(p23q24.3), +r(8)(p23q24.3)[1]. FISH studies showed no deletion of subtelomeric sequences for both child and mother indicating that no or little chromosomal euchromatic material has been deleted. These findings indicate that ring chromosome 8 without loss of subtelomeric sequences can be inherited and that carriers in a same family present with cognitive function ranging from mild mental retardation to normal intelligence.
Le Caignec
Cedric
C
Service de Génétique Médicale, Plateau Technique, Centre Hospitalo-Universitaire, 9, quai Moncousu, 44093 Nantes cedex, France. lecaignec@hotmail.com
Boceno
Michelle
M
Jacquemont
Sebastien
S
Nguyen The Tich
Sylvie
S
Rival
Jean-Marie
JM
David
Albert
A
D000015:Abnormalities, Multiple / Q000235:genetics*; D000328:Adult; D000550:Amblyopia / Q000235:genetics; D001289:Attention Deficit Disorder with Hyperactivity / Q000235:genetics; D002478:Cells, Cultured / Q000648:ultrastructure; D002540:Cerebral Cortex / Q000002:abnormalities; D002648:Child; D025063:Chromosome Disorders / Q000235:genetics*; D002898:Chromosomes, Human, Pair 8 / Q000235:genetics / Q000648:ultrastructure*; D004392:Dwarfism / Q000235:genetics*; D005260:Female; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging / Q000235:genetics; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007859:Learning Disabilities / Q000235:genetics; D008214:Lymphocytes / Q000648:ultrastructure; D008297:Male; D008831:Microcephaly / Q000235:genetics*; D010375:Pedigree; D011247:Pregnancy; D012303:Ring Chromosomes; D016615:Telomere / Q000648:ultrastructure; D016216:Ultrasonography, Prenatal