Subtle genetic alterations may represent one of the most common causes of moderate to severe mental retardation.

Hamerton, J.L., and L. Stranc. 1999. Defining the chromosomal basis of mental handicap. Lancet 354(Nov. 13):1659.

Knight, S.J.L., et al. 1999. Subtle chromosomal rearrangements in children with unexplained mental retardation. Lancet 354(Nov. 13):1676.

John L. Hamerton
University of Manitoba
Department of Biochemistry and Medical Genetics
Faculty of Medicine
Winnipeg, Manitoba R3E OW3
Canada

Samantha J.L. Knight
John Radcliffe Hospital
Molecular Haematology Unit
Institute of Molecular Medicine
Headington, Oxford OX3 9DS
United Kingdom

Leonie Stranc
University of Manitoba
Department of Biochemistry and Medical Genetics
Faculty of Medicine
Winnipeg, Manitoba R3E OW3
Canada

From Science News, Vol. 156, No. 21, November 20, 1999, p. 324. Copyright © 1999, Science Service.