Genetic Compensation in a Human Genomic Disorder

Abstract

Cytogenetic studies of the parents of a girl with the DiGeorge (or velocardiofacial) syndrome, who carried a deletion at 22qll.2, revealed an unexpected rearrangement of both 22qll.2 regions in the unaffected father. He carried a 22qll.2 deletion on one copy of chromosome 22 and a reciprocal 22qll.2 duplication on the other copy of chromosome 22. Genetic compensation, which is consistent with the normal phenotype of the father, was shown through quantitative-expression analyses of genes located within the genetic region associated with the DiGeorge syndrome. This finding has implications for genetic counseling and represents a case of genetic compensation in a human genomic disorder. Copyright © 2009 Massachusetts Medical Society. All rights reserved.