Presentation on theme: "Better Safe Than Sorry: The Biological Basis of Fetal Alcohol Syndrome and other Alcohol-Related Birth Defects."— Presentation transcript:
1Better Safe Than Sorry: The Biological Basis of Fetal Alcohol Syndrome and other Alcohol-Related Birth Defects
2When a mother drinks, her unborn child is exposed to alcohol.
3Alcohol-Related Birth Defects Include: Fetal Alcohol Syndrome (FAS)which is characterized by central nervous system problems low birth weight and height3. typical facial featuresFetal Alcohol Effects (FAE) which result from maternal alcohol abuse but are found in the absence of the full-blown syndrome
4The facial features of Fetal Alcohol Syndrome are: Small eyelid openings (palpebral fissures)Short, upturned noseLong upper lip (from nose to mouth) with a thin red border and a deficient central groove (philtrum)Reduced size of the head (microcephaly)
6FASFull-blown fetal alcohol syndrome (FAS) represents only the “tip of the iceberg” relative to all alcohol-related birth defects (ARBDs).ARBDs
7MATERNAL ALCOHOL ABUSE IS THE LEADING KNOWN CAUSE OF MENTAL RETARDATION IN THE WESTERN WORLD
8Children with alcohol-related birth defects typically have: attention deficitslanguage difficultieslearning disabilitiesimpulsive behaviorpoor judgment
9Whole brain Cross-section PRENATAL ALCOHOL EXPOSURE CAN PERMANENTLY DAMAGE THE BRAIN, AFFECTING IMPORTANT STRUCTURESSUCH AS THE CEREBELLUM AND CORPUS CALLOSUM,AS WELL AS SPECIFIC CELL POPULATIONS IN MANY OTHERREGIONS OF THE BRAINWhole brainCross-sectioncerebral hemispherescorpus callosumcerebellum
10Visualization of the brain of a normal individual (A) and two with FAS (B,C) shows permanent loss of the tissue indicated by the arrows (portions of the corpus callosum).NormalFASImages courtesy of Dr. S. Mattson
11of alcohol on development. Similarities in mouse and human embryogenesis provide opportunities to study the effectsof alcohol on development.Mouse(10 days old)Human(approx. 28 days old)EYEHEARTUPPER LIMB (ARM)3 mm.5 mm.
12Short palpebral fissures The facial features of Fetal Alcohol Syndromecan be seen in both a child and a mouse fetusthat were exposed to alcohol during development.child with FASmouse fetusesNarrow foreheadShort palpebral fissuresSmall noseSmall midfaceLong upper lip withdeficient philtrumalcohol-exposednormal
13The amount and timing of maternal alcohol use determine the type and extent of resulting birth defects.
14Alcohol can cause malformations and brain abnormalities in embryos that are only three to four weeks old.22 day old human embryo ( about 2 mm. long, the length of the ear on the US dime)Developingbrain
15ALCOHOL KILLS SPECIFIC CELLS IN THE DEVELOPING BRAIN Arrows surround a portion of the brain of a mouseembryo (viewed from the back) that is at a develop-mental stage corresponding to a day human.Cells killed by alcohol in the brain of a mouseembryo (at a comparable stage of developmentto that on the left) have taken up a dark blue stain.
16A close-up view of an alcohol-exposed CELLS THAT SHOULD FORM MIDLINE STRUCTURES OF THE BRAIN AND FACE ARE KILLED BY ALCOHOLDevelopingbrain andfaceHeartA close-up view of an alcohol-exposedmouse embryo shows cells killed by alcoholthat have taken up a dark blue stain.Mouse embryo (viewed fromthe front) at a stage correspondingto a day old human.
17MIDLINE STRUCTURES OF THE FACE AND BRAIN ARE DEFICIENT IN ALCOHOL-EXPOSED MOUSE EMBRYOS AND IN INDIVIDUALS WITH FASEYEEYENOSTRILSNOSTRILSMOUTHMOUTHACTHE FACE OF A CHILDWITH FULL-BLOWN FASHAS FEATURES THATCAN BE CAUSED BYDAMAGE TO MIDLINESTUCTURES.BDCOMPARISON OF THE FACE (A) AND INTERIOR OF THE BRAIN (B) OF A NORMALMOUSE EMBRYO AND ONE DAMAGED BY ALCOHOL (C&D) SHOWS THAT THE NOSTRILSARE ABNORMALY POSITIONED (C) AND THE BRAIN IS MISSING MIDLINE STRUCTURES (D).
18ALCOHOL KILLS SPECIFIC CELLS IN THE DEVELOPING BRAIN The pattern of cell death varieswith the stage of development.Cells killed byalcohol have taken updark blue stainA cut made through thearea outlined by arrowsprovides a view of the inside of the brain of a10 day mouse embryo(corresponding to a 28 day human)
19Alcohol also caused cleft lip in this mouse. This child with FAS hasa scar from a repairedcleft lip.Cleft lip can also be causedby genetic or environmentalagents other than alcohol.EXPOSURE TO ALCOHOLDURING DEVELOPMENTCAN CAUSE DAMAGETO ORGANS AND REGIONSOTHER THAN THE BRAINAlcohol also caused cleft lipin this mouse.
20By the ninth week of development the human fetus is about 24mm. long By the ninth week of development the human fetus is about 24mm. long. Damage caused by alcohol to the brain at this time and until birth can result in abnormal brain function.
21Excessive alcohol exposure can cause damage during all stages of prenatal development. Pre-implantation: first 2 weeksEmbryonic: 3-8 weeks after conceptionFetal: from week 9 until birth
22Alcohol can cause permanent damage to a baby before most women realize they are pregnant.
24Alcohol-related birth defects are expensive: $Monetarily — for treatment, care, and lost productivity. Costs are between $800,000 - $2 million over a lifetime for each individual with FAS.Socially — relative to delinquency and to emotional drains on involved families.