title: Ring chromosome 22 in a mentally retarded child and mosaic 45,XX,-15,-22,+t(15;22)(p11;q11)/46,XX,r(22)/46,XX karyotype in the mother.
abstract: A ring chromosome 22 is described in a 6-year-old mentally retarded boy, who presented a dysmorphic syndrome. The ring chromosome 22 was inherited from the mother, in whom a 46,XX/46,XX,r(22)/45,XY,-15,-22,+t(15;22)(p11;q11) mosaic karyotype was found, indicating a high degree of instability of the chromosome(s) 22 in this woman.
mesh_terms: D000328:Adult; D002648:Child; D002869:Chromosome Aberrations; D002901:Chromosomes, Human, 13-15; D002904:Chromosomes, Human, 21-22 and Y; D005260:Female; D006801:Humans; D008607:Intellectual Disability / Q000235:genetics*; D007621:Karyotyping; D008297:Male; D009030:Mosaicism; D009123:Muscle Hypotonia / Q000235:genetics; D010641:Phenotype; D013577:Syndrome; D014178:Translocation, Genetic