3What are birth defects?Birth defects are defined as abnormalities of structure, function, or body metabolism that are present at birth.These abnormalities lead to mental or physical disabilities or are fatal.There are more than 4,000 different known birth defects ranging from minor to serious.
4With every pregnancy, the chance for a baby to be born with a birth defect is… 3-5%
6Maintaining a healthy lifestyle is important during pregnancy What do you think having a healthy lifestyle might mean?
7Which of the following can cause more harm to a fetus? CigarettesCrack/CocaineHeroinAlcohol
8“Alcohol causes more damage to the developing fetus than any other substance, including marijuana, heroin, and cocaine.”Institute of Medicine, 1996
9Effects of AlcoholConsumption of alcohol during pregnancy can have devastating effects on the babyNo amount of alcohol is okayWhat kinds of effects do you think alcohol can cause during pregnancy?
10Fetal Alcohol Syndrome The name commonly given to the group of physical features found in children exposed to alcohol during pregnancyCommon features include:Classic facial featuresGrowth problems in both weight and heightHeart, liver, and kidney problemsVision and hearing problemsDifficulties with learning, attention, memory, and problem solving
11Characteristic FAS Facial Features Source: www. niaaa.nih.gov/Source:
12Fetal Alcohol Syndrome Approximately 1 in every 100 children born have some effects of alcoholThe leading known preventable cause of mental retardation and birth defectsIt is preventable by avoiding alcohol during pregnancy
13Fetal Alcohol Syndrome One child with FAS costs about $800,000 in health care costs over their lifetimeIt is found in all racial and economic groupsThe effects are not reversible and do not go away with time
15Effects of Smoking Smoking during pregnancy can also affect the baby Smoking during pregnancy can also affect the babyBabies born to women who smoke are usually small at birth (under 5 ½ pounds)Preterm delivery is also commonPossible low IQWhat effects do you think smoking might have on a baby?
16Effects of Medications Medications you take can also be harmful during pregnancyThe most devastating ones include Accutane and anti-seizure medicationsAsk your doctor about medications you are takingAre medications usually something you would think would be harmful to a baby? What could you do to find out?
17Pregnancy Exposure Program Fullerton Genetics Center (800)
18Effects of Good Prenatal Care Effects of Good Prenatal CareGood prenatal care is the first step to ensuring a healthy babyThis includes eating healthy, exercising, getting enough sleep, and seeing your doctorHowever, there is never any guarantee
19Types of genetic diseases Multifactorial disordersChromosomal disordersSingle gene disordersMitochondrial disorders
20Multifactorial Disorders No clear inheritance patternRecurrence risk difficult to estimateCombination of genetic and environmental factors
22Neural Tube DefectsIf the neural tube doesn’t zipper on the back, the baby will have spina bifidaIf the tube is open at the head, the baby will have anencephaly
23Spina Bifida Occurs in 1 out of every 1,000 births One of the most common birth defectsCost to society is about $532,000 for each child with spina bifidaSurgery is done immediately following birth to close the openingSome surgery is also being done while the baby is still in the womb
25Spina Bifida Three types: Spina Bifida Occulta Meningocele Vertebrae are slightly malformedMeningoceleOpening in the vertebrae; membranes and fluid protrudeMyelomeningoceleOpening in the vertebrae; membranes, fluid, and spinal cord protrude
27Spina Bifida- Who’s at Increased Risk? Women who have previously had a child with a NTDWomen who are insulin-dependent diabeticsWomen using some anti-seizure medicationsWomen with medically diagnosed obesityWomen exposed to high temperatures early in pregnancyIt is more common in Caucasian and Hispanic women
28Spina Bifida- How do you prevent it? Folic acid!!The recommended daily allowance is 400 microgramsBut it can be as much as 4000 micrograms in women at high-riskFolic acid should be taken before conception through the third month of pregnancyMay reduce your risk by 70%Half of all pregnancies are unplannedAll women of child bearing age should take a vitamin with folic acid!Not all cases of spina bifida are preventable. Some women who take the recommended amount of folic acid still have children with neural tube defects and we believe there is some underlying genetic cause that explains this.
29AnencephalyOccurs when the neural tube doesn’t close at the back of the skullWithout the complete skull, the brain fails to developThese children are born with a brain stem, but no brainMost survive only hours or days after birth
30AnencephalyThe presence of the brain stem allows these children to breathe and their hearts to beat, but they have no cognitive function.
32Cleft Lip and Palate Occurs in 1 in every 700 births The lip and palate form sometime around 6-12 weeks of pregnancySurgery is done to close the lip and palateChildren usually do very well with the surgery and develop normal speechSome studies have shown that folic acid can also be useful in preventing cleft lip and palateMore common in children of Asian descentHas many causes, some of which are genetic and not preventable
38Effects of Genetics Genes also play a role in how we develop Some birth defects are due to changes in our genesThese cannot be predicted or preventedExamples:Down syndromeSome heart defectsSickle cell diseaseCystic fibrosisExplain some genes and chromosomes, show karyotype
39What is a genetic condition? Any condition caused by a change in a gene that leads to physical and/or mental differencesMay present at birth or later in lifeThese gene-changes can happen by chance or can be inherited
40Background on genetics Every human being has about 30,000 genes that determine everything from eye color to the development of our physical and biochemical systems.Genes come in pairs, and we inherit half of our genes from each parent.Genes are packaged on 46 chromosomes inside our cells
51Turner syndrome 45, XO Incidence 1:2500 Major features: Short stature Lack of sexual development at pubertyInfertilityHeart defectsWebbed neck
52Single Gene DisordersDisorders in which single genes are altered. Sometimes the altered genes occur pre/post-fertilization, or can be inherited from a parent in the following pattern:Autosomal recessiveAutosomal dominantX-linked
53Autosomal recessive Recessive gene on an autosome Inherit two non-working copies to be “affected”Two “carriers” must each pass on the non-working copy. Chance to have an affected child is 25%.
54How much of the world’s population is married to their cousin? A. 1 out of 1,000 (0.1%)B. 1 out of 100 (1%)C. 1 out of 10 (10%)D. 1 out of 3 (33%)
55Gives additional 1.7-2.8% risk over general population First cousins have an increase risk of having a child with a birth defectGives additional % risk over general population= 6%
56Sickle Cell Anemia Incidence 1 in 500 (African Americans) Carrier frequency is 1 in 8Mutation in B-globin gene on chromosome 11Features:Joint, stomach, chest or muscle painSwelling of abdomenInfectionsDamage to organs
57Cystic fibrosis Incidence 1 in 2500 (Caucasians) Carrier frequency 1 in 25CF gene on chromosome 17Features:Develop thick mucusSterility in malesAbnormal sweat glandsPancreatic insufficiencyLife expectancy 30 years in severe cases
58Autosomal dominant Dominant gene on an autosome Inherit one non-working copy to be “affected”Parent with genetic condition has a 50% chance of passing to offspring
59Marfan syndrome Incidence 1 in 5,000 Due to changes in the fibrillin 1 precursor (FBR 1) gene on chromosome 15Major features:Tall, thin statureHeart defectPectus excavatumJoint laxity
60Marfan syndrome – Physical Exam Hand signArm spanDislocated lensesWrist signHeartproblems
62Famous People with Marfan Syndrome Flo Hyman – US olympic volleyball player – died of aortic rupture in at a game in JapanAbraham Lincoln – suspected diagnosisVincent Schiavelli –actor from Ghost, People vs. Larry Flynt, Tomorrow Never Dies, etc.Honorary Co-Chair of National Marfan SocietyDied in 12/2005 of lung cancer
63Neurofibromatosis Incidence 1 in 3000 Mutations in NF1 (17q) and NF2 (22)Common features:Café au lait patchesNeurofibromasFreckling in groin/armpits
64Achondroplasia Incidence: 1 in 25,000 Mutation in fibroblast growth receptor 3 (FGFR 3) on chromosome 4Major features:Short limbsCurvature of lower spineProminent forehead
79Family History (Pedigree) Age or date of birth (and, for all family members who have passed on, age at death and cause of death).Medical problems such as:CancerHeart diseaseDiabetesAsthmaMental illnessHigh blood pressureStrokeKidney diseaseAlcoholismBirth defects such as spina bifida, cleft lip, heart defects, others.Learning problems, mental retardation.Vision loss/hearing loss at a young age (remember to record the age it began).Family members with other known medical problems
81Medical HistoryMay be provided through referring physician, collection of medical records, or interviews with the patient or family membersOften provides important clues pointing to a particular diagnosisIdentifies the family’s main areas of concerns and specific questions that need to be addressed during the sessionAnother important opportunity to complete a psychosocial assessment
82Physical Examination Helps to establish or rule out a diagnosis Based on a standard physical examinationIncorporates additional elements:Dysmorphology examinationSpecific elements may be included dependent upon diagnoses under consideration
83Morphology(n) The branch of biology that deals with the structure of animalsBasically the study of our pieces & parts and how they fit togetherDiscuss the basics of MorphologyWebster's defines “Morphology” as the branch of biology that deals with the structure of animalsBasically it is a study of our pieces and parts and how they fit together
84DysmorphologyAltered developmentThe study of malformation syndromes
85What does Dysmorphology have to do with Genetics? Clinical Geneticists use dysmorphology to give them clues as to what genetic syndrome (if any) an individual hasA genetic syndrome is often like a puzzle and the dysmorphic features are like the puzzle piecesClinical Geneticists try to figure out what may be causing a person’s symptomsThey look at the different symptoms and try to see if they fit together to fit into a known SyndromeSo, you can think about a person’s dysmorphic features as puzzle piecesWe try to fit them together and see if we can create a picture of a known syndromeWhy is it good to know what syndrome someone has?There may be other health problems that we are missingIt may tell us what treatment would work best