This document discusses basic concepts in human genetics including genes, chromosomes, DNA, alleles, dominant and recessive traits, and genetic disorders. It covers key topics like the human genome, inheritance from parents, genetic testing methods like amniocentesis and chorionic villus sampling, influences on prenatal development, and genetic counseling.

1. HUMAN GENETICS MISS SHENELL A. DELFIN, RN LECTURER

8. Eye Colour A heterozygous brown-eyed father and a blue-eyed mother: 50:50 chance of being either brown eyed or blue eyed

9. DOMINANT AND RECESSIVE CHARACTERISTICS Characteristics in the left-hand column dominate over those characteristics listed in the right-hand column . * sex-linked characteristic DOMINANT TRAITS RECESSIVE TRAITS eye coloring brown eyes grey, green, hazel, blue eyes vision farsightedness normal vision normal vision normal vision normal vision nearsightedness night blindness color blindness* hair dark hair non-red hair curly hair widow's peak blonde, light, red hair red hair straight hair normal hairline facial features dimples freckles broad lips no dimples no freckles thin lips

14. GENETIC DISORDERS DOWN SYNDROME

16. PATAU’S SYNDROME

17. Turner Syndrome Webbed neck – spaced nipples

19. Chorionic Villus Sampling: Done in the first trimester for genetic studies. The cells obtained are identical to those of the fetus, grown and analyzed. Complications include pregnancy loss and limb abnormalities. Done as early as week 5 of pregnancy to detect any genetic disorders Amniocentesis: Amniotic Fluid (20 ml) is withdrawn under US guidance, and is analyzed for prenatal diagnosis of karyotypic abnormalities such as: congenital defects, fetal lung maturity, and NTD. Done at the 14 th -16 th week of pregnancy Complications include pregnancy loss, amniotic fluid leakage, fetal injury This process is indicated for: Women over 35 y. of age: ↑ risk of malformations- 21, 18, 13 trissomy Women who had a child with a chromosomal abnormality.

20. CHORIONIC VILLUS SAMPLING

21. AMNIOCENTESIS

27. MULTIPLE BIRTHS TWINS.ppt