Birth Defects Essay -- essays research papers fc

Birth defects, or congenitalmal arrangements, are the faulty formation ofstructures or body parts present at birth.Sporadic, hereditary, or acquired defects may beimmediately observed or may become manifest later(prenominal) in life they may be visible on the bodysurface or present internally. Birth defects may belife impending and require surgical correction, orthey may interfere with function or appearance. Itis estimated that about 3% of all children are bornwith major defects minor defects or variations areestimated to occur in 10% to 15% of births.Malformations may be single or multiple. Multiplemalformations that occur in a regular perceptiblepattern are referred to as syndromes--forexample, the FETAL ALCOHOL SYNDROMEsometimes observed in infants of mothers whodrank heavily when pregnant. Birth defects mayresult from the action of genes, chromosomes, orthe milieu on the developing fetus, but oftenthe cause cannot be determined. Inherited DefectsAbnormal genes cause a signif icant number ofdifferent birth defects. nearly can be identified as asingle-gene disorder that is inherited in a simpleMendelian mode, that is, either a dominant or arecessive pattern. For example, lobster claw tarnish of the hands and feet (split hands orfeet) is inherited and results from the effect of asingle dominant gene. A person who has thisdeformity runs a 50% risk (1 in 2) of bearingoffspring who will inherit the gene and willtherefore also be affected. Autosomal rece...