EVALUATION OF GENETIC AND ENVIRONMENTAL COMPONENTS OF ORODENTAL ANOMALIES IN BIRTH DEFECTS

Abstract

Birth defects can be defined as any deviation from normal development present since birth which may be manifested at any stage of development, prenatal, at birth, neonatal, or later in life. (Temtamy et al., 1993).

Congenital malformations are developmental defects apparent on inspection at the time of birth or in the neonatal period. They can be genetically determined due to gene mutations or chromosomal aberrations or due to environmental factors or the combination of both.(Chaturvedi and Banerjee, 1993)

The frequency of birth defects in any population is one of the most important parameters which need to be assessed periodically for early monitoring of teratogenic and mutagenic exposure and investigate the relative burden of genetic versus environmental etiology (Temtamy et al., 1993).

About 3% of human newborns have a congenital anomaly. They may present as microscopic change or as gross alterations recognizable by clinical examination of the body. (Emery and Rimoin,1990)

Teratogenesis is environmental interference with normal prenatal development between conception and birth in contrast to genetic interference which is predetermined before the time the sperm and the ovum unite to form the zygote. Our knowledge about the causes of congenital defects are quite limited (Shepard 1988).