Ring chromosome 22 and autism: report and review.
Ring chromosome 22 has been described in over 50 cases. A characteristic phenotype has not been fully delineated; however, long face, thick eyebrows, 2-3 toe syndactyly, mental retardation, adequate somatic growth and the absence of major malformations are noted in many cases. An 11-year-old boy with ring chromosome 22 and 46,XY,r(22)(p11.31-q13.31 approximately q13.33) karyotype presented with global developmental delay, autistic disorder, and dolichocephaly, apparently low-set and large ears, midface hypoplasia, and 2-3 toe syndactyly. This is the second report of a ring chromosome 22 with autistic disorder. There appears to be an association between abnormalities of chromosome 22, including r(22), and autistic disorder; however, this occurrence may be a result of the association of autistic disorder with mental retardation rather than specifically due to r(22). The physical findings in this case also suggest that ring chromosome 22 causes a subtle but distinct phenotype which has previously been proposed.
MacLean
J E
JE
Department of Pathology and Molecular Medicine, McMaster University, and Hamilton Health Sciences Corporation, Ontario, Canada.
Teshima
I E
IE
Szatmari
P
P
Nowaczyk
M J
MJ
D000015:Abnormalities, Multiple / Q000235:genetics*; D001321:Autistic Disorder / Q000235:genetics*; D002648:Child; D002869:Chromosome Aberrations / Q000235:genetics*; D025063:Chromosome Disorders; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D012303:Ring Chromosomes