Cytogenetic diseases

Abstract

The study of human chromosomes in readily accessible material such as lymphocytes has been possible for over 27 years. The development of banding techniques was the next break-through. Following these discoveries, chromosomes identification techniques were quickly applied to clinical practice. Researchers identified an extra chromosome 21 in patients with down syndrome. Identification of other classic cytogenetic disorders soon followed. Cytogenetic abnormalities are an important etiologic factor in spontaneous abortion and may be relatively common in what was previously considered nonspecific mental retardation. Some cytogenetic disorders are fairly frequent and cytogenetic analysis makes it possible to define the precise nature of the abnormality and allows appropriate counseling of the family. In this paper the most important cytogenetic disorders are discussed.