GENETICS & HEREDITY

1. GENETICS & HEREDITY

2. GENETICS - The study of the way animals & plants pass on to their offspring such as: • eye color, hair color, height, body build, blood types, intelligence, gender, etc. • HEREDITY - Characteristics that a child receives from both parents

3. CYTOPLASM: Substance of a cell outside of the nucleus • CELL: Basic unit of all living matter (Adult = over 10 trillion cells) NUCLEUS: Central point of cell / contains genetic coding for maintaining life systems and issuing commands for growth & reproduction CHROMOSOMES: 46 in each Nucleus (23 pairs) GENES: bands on chromosomes (thousands of genes) DNA on genes (billions of DNA)

4. ? ? ? ? ? ? ? ? • How many chromosomes are there in each cell? • 46 CHROMOSOMES or 23 PAIRS • How many chromosomes are in Reproductive (egg & sperm) or Germ cells? • 23 CHROMOSOMES • (combined = the 46 chromosomes)

5. CELL DIVISION • MITOSIS: Cell divides by copying the DNA - cell splits - new cell with normal number of chromosomes (Cell growth & repair) • MEIOSIS: Creates 1/2 sets of chromosomes • Women = 23 Men = 23Combined = 46

6. Female Sex Cells XX (Ovum or Egg) • Male Sex Cells XY (Sperm) • Baby Girl = XX Baby Boy = XY • Conception is the union of an OVUM and the SPERM • Gender is determined by the father! • Someone should have told King Henry VIII!

7. DOMINATE Gene: More powerful - trait seen in person • RECESSIVE Gene: Weaker and hides in the background. Trait can only determine when two of them are present - may show up in future generations. • CARRIER: Has a recessive gene that is not visible • SEX-LINKED: Mother passes the recessive X to son • Color-blind male receives the trait from his mother. • The mother is usually not color-blind herself. • B = BROWN eyes (dominate) b = BLUE eyes (recessive) • BB = BROWN eyes • bb = BLUE eyes • Bb = BROWN eyes but carry the recessive BLUE eye gene

8. MULTIPLE BIRTHS • ZYGOT: the cell that is formed when a sperm fertilized an egg (ovum) • MONOZYGOT: Identical Twins 1 Egg + 1 Sperm • Fertilized ovum splits into 2 identical cells - Always the same gender • DIZYGOT: Fraternal Twins 2 Eggs + different Sperm • Will look different - May be different or the same gender • MULTIPLE BIRTHS: More than 2 • May be identical, fraternal or both - May be different or the same gender • CONJOINED (Siamese) TWINS: Ovum splits apart, but the separation is not completed. Babies are joined at some part of their bodies.

9. What 4 FACTORS may contribute to Multiple Births? • 1) History in the family • 2) Increased hormones naturally • More than 1 egg released • 3) Fertility Drugs • More than 1 egg released • 4) Age 32-36 • Likelihood of multiple pregnancies in the United States • Twins: Blacks- 1 in 73 Whites 1 in 93 • Triplets: 1 in 10,000 • Quadruples: 1 in 620,000

10. Multiples in the Womb

11. Sex - Linked or X - LinkedDefect: When an X-gene from the mother is faulty. There is a 50/50 chance of the child inheriting the disorder. • Syndrome: When a group of signs and symptoms occur together and characterize a particular problem. • CongenitalMalformation: A condition that is present at birth. • Multi-factorialDefects: Interaction of genes with other genes OR with environmental factors. • ChromosomalError: The fertilized egg cell that contains chromosomes in an abnormal number, structure or arrangement.

12. Birth Defects

13. Notes Write a paragraph describing your dream vacation with at least one child. How would that change if your child was in a wheelchair? Deaf or blind?

14. The King and the Scratched Diamond… Once there was a king who had a beautiful, large pure diamond. There was no other diamond like it in the world. One day, it became deeply scratched. The king told his best diamond cutters, “I’ll promise you a great reward if you can remove the imperfection from my jewel.” But they could not. The king was very upset. Many months later, a man came to the king. He promised to make the diamond even more beautiful than it ever had been. Impressed by the man’s confidence, the king consented. He watched as the man engraved an exquisite rosebud around the blemish and used the scratch to make its stem. --Parable of the Preacher of Dubno from Jewish Folklore

15. FACTS • About 150,000 babies are born each year with birth defects. • The parents of one out of every 28 babies receive the frightening news that their baby has a birth defect • There are over 4,000 known birth defects • Birth defects are the leading cause of death in the first year of life

16. What is a Birth Defect? • A birth defect is an abnormality that affects the structure or function of the body. • Almost everyone is born with some type of imperfection. Most, such as a birthmark, are relatively minor. Some babies are born with more serious problems. These are referred to as birth defects.

17. What causes birth defects? • There are three basic factors that influence birth defects: • Heredity • Environment • A combination of heredity and the environment. The causes of birth defects differ greatly. Some are inherited from one or both parents. Some are caused by controllable factors in the environment.

18. What are some environmental factors? • Environmental factors include: • Diet • Disease or infections of the mother • Harmful substances ingested by the mother (drugs or alcohol) • Exposure to outside hazards such as radiation

19. Drug Related Birth Defects • Thalidomide

20. Low Birth Weight Conjunctivitis (Pinkeye) STD Related Birth Defects

21. Can birth defects be prevented? • Prenatal development occurs very rapidly. In only a few weeks the baby develops all of its body systems needed to survive and live normally. During this time, the fetus is totally dependant upon the mother to provide nourishment and food.

22. Prevention of Birth Defects • While the causes of most birth defects are not known, there are a number of steps a woman can take to reduce her risk of having a baby with a birth defect. • Visit a health care provider for a pre-pregnancy check up. Especially if a woman has a history of health problems. • Before and during pregnancy, take a daily multivitamin containing 400 mcg of the B-vitamin Folic Acid. • Avoid alcohol, drugs, smoking, prescription or over-the-counter medication with out checking with a health care provider.

23. Factors that contribute to Birth Defects: • Over 35 years of age • Overweight • Underweight • Jewish decent (Tay-Sachs Disease) • African American (Sickle Cell Anemia) • Last birth was less than 12 month ago • Has had a baby that weighed less than 5 ½ pounds • Has had 3 or more miscarriages • Has had more than 5 pregnancies • Has had a still born baby

24. Drinks alcohol and/or smokes • Has personal habits that are different from most people • Uses prescription drugs • Has used street drugs • Takes excessive vitamins • Drinks caffeine (no more than 300mg) • Has had exposure to chemicals • Live in a home built before 1955 • Constant exposure to cats • Has had x-rays during pregnancy • RH Factor • Miscarriage

25. Ailments that run in families: • High blood pressure • Diabetes • Hemophilia • Sickle cell anemia • Thalassemia • Birth defects • Mental Retardation • Cystic Fibrosis Health Problems: • Genital Herpes • Gonorrhea • Syphilis • Epilepsy • Diabetes • High blood pressure • Heart disease • Anemia

26. Types of Birth Defects: 1. Malformations present at birth Defects such as congenital heart malformation, spina bifida (open spine), cleft palate, clubfoot, etc. 2. Inborn errors of metabolism Defects such as PKU, Tay Sachs disease 3. Blood Disorders Defects such as sickle cell anemia, hemophilia, thalassemia. 4. Chromosomal Abnormalities Conditions such as Down’s Syndrome, Klinefelter syndrome, Turner Syndrome. 5. Prenatal damage Cases include certain infections, drugs, maternal disorders such as diabetes, high blood pressure, Rh disease, umbilical cord accidents, difficult labor or delivery, premature birth.

27. Detection of birth defects: • Some birth defects can be diagnosed before birth. Some prenatal tests that can be taken are: • Ultrasound • Amniocentesis • Chorionic Villus Sampling

28. Ultrasound • Imaging procedure in which sound waves are bounced off the fetus to produce a picture. • Can show development of the fetus and can detect certain defects involving development of organs and the skeleton. • Frequently used to verify the due date of the baby, check the baby’s growth, or determine the presence of multiple fetuses. • May also be called a sonogram.

29. Amniocentesis • A long needle is inserted through the abdominal wall and into the uterus. A small amount of amniotic fluid is removed and analyzed. • Amniotic fluid contains cells from the fetus. • Chromosomes are examined for possible defects. • Risk of infection and risk of causing the body to abort the fetus. • NOT a routine procedure. Only used when there is valid medical reason such as to detect Down’s Syndrome.

30. Chorionic Villus Sampling • Done only under extremely serious conditions. • Similar to amniocentesis, but done earlier and with quicker results. • An ultrasound is used to guide a hollow tube through the vagina and into the uterus. • Samples of villi are snipped or suctioned off for analysis. • Villi are minute pieces of tissue that protrude from the membrane surrounding the fetus.

31. What if the tests indicate there is a problem? • Confer with your doctor in deciding what to do. • Advances in prenatal therapy now make it possible to treat some birth defects before birth. • Depending on the defect, prenatal surgery can be performed. • Genetic Counseling is also available.

32. What is Genetic Counseling? • Genetic counseling is a service to help individuals and families translate scientific knowledge into practical information. • A genetic counselor works with a person or family that may be at risk for an inherited disease or abnormal pregnancy outcome, discussing their chances of having children who are affected.

33. Cleft Lip/Palate • Cleft palateCleft palate occurs when the roof of the mouth does not completely close, leaving an opening that can extend into the nasal cavity. • The cleft may involve either side of the palate. It can extend from the front of the mouth (hard palate) to the throat (soft palate). Often the cleft will also include the lip. • Cleft palate is not as noticeable as cleft lip because it is inside the mouth. It may be the only abnormality in the child, or it may be associated with cleft lip or other syndromes. In many cases, other family members have also had a cleft palate at birth. • Cleft lipCleft lip is an abnormality in which the lip does not completely form during fetal development. The degree of the cleft lip can vary greatly, from mild (notching of the lip) to severe (large opening from the lip up through the nose).

34. Cleft Palate

35. Cleft Lip/Cleft Palate • Can affect anyone • Appears at birth • Congenital malformation – Multi-factorial • Two sides of lip and/or pallet not joined • Treatment - surgery

36. Club Foot • Clubfoot or talipes is a congenital deformity of the foot that occurs in approximately 1:1000 births with half of them being bi-lateral (both feet) and it is twice as common in boys as in girls. The foot has a typical appearance of pointing downwards and twisted inwards. Since the condition starts in the first trimester of  pregnancy, the deformity is quite established at birth, and is often very rigid. • Treatment options: • Serial Plaster Casting • Splints • Non-Surgical Treatment Methods • Ponseti Method • French Physiotherapy Method • Botox - botulinum toxin • Surgery

37. Clubfoot • Affects anyone • Appears at birth • Congenital malformation – Multi-factorial • Foot and ankle twisted, making it impossible to walk normally • Treatment - surgery

38. Down’s Syndrome • Down syndrome (DS) is a condition in which extra genetic material causes delays in the way a child develops, and often leads to mental retardation. It affects 1 in every 800 babies born. • Normally, at the time of conception a baby inherits genetic information from its parents in the form of 46 chromosomes: 23 from the mother and 23 from the father. In most cases of Down syndrome, however, a child gets an extra chromosome - for a total of 47 chromosomes instead of 46. It's this extra genetic material that causes the physical and cognitive delays associated with DS. • The symptoms of Down syndrome can vary widely from child to child. While some kids with DS need a lot of medical attention, others lead very healthy and independent lives.

39. Down’s Syndrome • Common if baby has young or old parents • Appears at birth • Chromosomal error • Effects – Some form of mental retardation, oval shaped eyes, thick big tongue, short neck, back of head is flat, small ears, common heart problems • Surgery, special assistance

40. Muscular Dystrophy • Muscular dystrophy (MD) is a genetic disorder that weakens the muscles that help the body move. People with MD have incorrect or missing information in their genes, which prevents them from making the proteins they need for healthy muscles. • MD weakens muscles over time, so children, teens, and adults who have the disease can gradually lose the ability to do the things most people take for granted, like walking or sitting up. Someone with MD might start having muscle problems as a baby or their symptoms might start later. Some people even develop MD as adults. • The life expectancy for many of these forms of muscular dystrophy depends on the degree to which a person's muscles are weakened as well as how much the heart and lungs are affected.

41. Muscular Dystrophy • Affects – anyone • Appears in childhood and adulthood • Multi-factorial, sex –linked • Weakening of muscles. Inability to walk, move, wasting away and sometimes death • No treatment

42. PKU (Phenylketonuria)  • Phenylketonuria (PKU) is an recessive genetic disorderr characterized by a deficiency in the enzyme phenylalanine hydroxylase (PAH). • This enzyme is necessary to metabolize the amino acid phenylalanine to the amino acid tyrosine. When PAH is deficient, phenylalanine accumulates and is converted into phenylketones, which are detected in the urine. • Left untreated, this condition can cause problems with brain development, leading to progressive mental retardation and seizures. However, PKU is one of the few genetic diseases that can be controlled by diet. A diet low in phenylalanine and high in tyrosine can bring about a nearly total cure.

43. PKU

44. PKU • Affects anyone • Appears at birth • Recessive disorder • Abnormal digestion of protein, mental retardation, hyperactivity • Preventable diet

45. Spina Bifida • Spina bifida is a birth defect that involves the incomplete development of the spinal cord or its coverings. The term spina bifida comes from Latin and literally means "split" or "open" spine. • Spina bifida occurs at the end of the first month of pregnancy when the two sides of the embryo's spine fail to join together, leaving an open area. In some cases, the spinal cord or other membranes may push through this opening in the embryo's back. The condition can typically be detected before a baby is born and treated right away.

46. Neural Tube Defects • Spina Bifida

47. Spina Bifida • Affects anyone • Appears at birth • Multi-factorial, Prenatal damage • Varying degrees from slight cyst to open spine (sores, infertile, legs paralyzed, poor bladder and bowel control, death) • Surgery and physical therapy

48. Sickle Cell Anemia • Sickle cell anemia is an inherited blood disorder that mostly affects people of African ancestry. • A blood disorder that affects hemoglobin. • Sickle cell anemia occurs when a person inherits two abnormal genes (one from each parent) that cause their RBCs to change shape. Instead of being flexible and disc-shaped, these cells are more stiff and curved in the shape of the old farm tool known as a sickle. • Sickle cells tend to clump together, making red blood cells sticky, stiff, and more fragile. These sickle cells can clog blood vessels and deprive the body's tissues and organs of the oxygen they need to stay healthy. • Unlike normal RBCs that last about 4 months in the bloodstream, fragile sickle cells break down after only about 10 to 20 days, which usually causes anemia.

49. Sickle Cell Anemia • Affects primarily blacks • Appears at birth • Recessive disorder, blood disorder • Abnormal blood cells, bout of pain, heart and kidney failure, less oxygen to all parts of the body. Death in childhood. Damage to adult vital organs. • Blood transfusions

50. Polydactyl • A congenital anomaly consisting of supernumerary fingers or toes. Each hand or foot has six digits. • Although the condition is usually not life-threatening or even particularly debilitating, most people in Western societies have the extra digits removed surgically. • The extra digit is usually a small piece of soft tissue; occasionally it may contain bone without joints; rarely it may be a complete, functioning digit.