<Ul> <Li> A congenital physical anomaly is an abnormality of the structure of a body part . An anomaly may or may not be perceived as a problem condition . Many, if not most, people have one or more minor physical anomalies if examined carefully . Examples of minor anomalies can include curvature of the 5th finger (clinodactyly), a third nipple, tiny indentations of the skin near the ears (preauricular pits), shortness of the 4th metacarpal or metatarsal bones, or dimples over the lower spine (sacral dimples). Some minor anomalies may be clues to more significant internal abnormalities . </Li> <Li> Birth defect is a widely used term for a congenital malformation, i.e. a congenital, physical anomaly which is recognizable at birth, and which is significant enough to be considered a problem . According to the CDC, most birth defects are believed to be caused by a complex mix of factors including genetics, environment, and behaviors, though many birth defects have no known cause . An example of a birth defect is cleft palate, which occurs during the fourth and seventh week of gestation . Body tissue and special cells from each side of the head grow toward the center of the face . They join together to make the face . A cleft means a split or separation; the "roof" of the mouth is called the palate . </Li> <Li> A congenital malformation is a congenital physical anomaly that is deleterious, i.e. a structural defect perceived as a problem . A typical combination of malformations affecting more than one body part is referred to as a malformation syndrome . </Li> <Li> Some conditions are due to abnormal tissue development: <Ul> <Li> A malformation is associated with a disorder of tissue development . Malformations often occur in the first trimester . </Li> <Li> A dysplasia is a disorder at the organ level that is due to problems with tissue development . </Li> </Ul> </Li> <Li> It is also possible for conditions to arise after tissue is formed: <Ul> <Li> A deformation is a condition arising from mechanical stress to normal tissue . Deformations often occur in the second or third trimester, and can be due to oligohydramnios . </Li> <Li> A disruption involves breakdown of normal tissues . </Li> </Ul> </Li> <Li> When multiple effects occur in a specified order, it is known as a sequence . When the order is not known, it is a syndrome . </Li> </Ul> <Li> A congenital physical anomaly is an abnormality of the structure of a body part . An anomaly may or may not be perceived as a problem condition . Many, if not most, people have one or more minor physical anomalies if examined carefully . Examples of minor anomalies can include curvature of the 5th finger (clinodactyly), a third nipple, tiny indentations of the skin near the ears (preauricular pits), shortness of the 4th metacarpal or metatarsal bones, or dimples over the lower spine (sacral dimples). Some minor anomalies may be clues to more significant internal abnormalities . </Li> <Li> Birth defect is a widely used term for a congenital malformation, i.e. a congenital, physical anomaly which is recognizable at birth, and which is significant enough to be considered a problem . According to the CDC, most birth defects are believed to be caused by a complex mix of factors including genetics, environment, and behaviors, though many birth defects have no known cause . An example of a birth defect is cleft palate, which occurs during the fourth and seventh week of gestation . Body tissue and special cells from each side of the head grow toward the center of the face . They join together to make the face . A cleft means a split or separation; the "roof" of the mouth is called the palate . </Li> <Li> A congenital malformation is a congenital physical anomaly that is deleterious, i.e. a structural defect perceived as a problem . A typical combination of malformations affecting more than one body part is referred to as a malformation syndrome . </Li>

What percentage of birth defects have no known cause