Genetics

• DNA

  Basic building block of genes-double helix of sugar phosphate backbone and nucleotide bases (A, T, G, & C)
• Genes

  Segments of DNA; a pack (sequence) of instructions for a unique body function.

  *The basic unit of heredity*
• Chromsomes

  Made up of DNA gene segments
• Genome

  Represents an organism's full set of DNA and genes
• Epigenome

  Chemical compounds on outside (epi) of DNA strands. Act to regulate gene expression.
• Mutations

  Any change in a gene's DNA sequence away from normal.
• Polymorphisms

  A type of mutation (or change in DNA sequence) but are a common form of a gene which causes genetic variation/diversity (trait) in the human genome.
• Genotype

  A person's genetic make-up
• Phenotype

  The ways genes are expressed (eye color, hair color, etc.)

  *The physical manifestations of a persons genetic makeup*
• Diploid

  Cell with 46 paired chromosomes
• Allele

  Different forms of the same gene
• Genomics

  Study of all genes as a whole
• Autosomal Dominant Disorders

  -Familial hypercholesterolemia

  -Polycystic kidney disease

  -Neurofibromatosis type 1

  -Marfan syndrome

  -Achondroplasia

  -Huntington's disease
• X-linked Recessive Gene Conditions

  -Males affected much more often

  -Examples: Hemophilia (Factor VIII), Duchenne muscular dystrophy and color blindness
• Chromosomal Abnormalities

  -Trisomy 21: Down syndrome, mental retardation

  -Trisomy 18: Edwards syndrome

  -Trisomy 13: Patau syndrome
• Sex Chromosomal Abnormalities

  -Klinefelter syndrome (XXY): male genitalia, gynecomastia, long limbs, tall, slim, hypogonadism and infertility.

  -Turner syndrome (45, X): short stature, webbed neck, extra skin folds, gonadal dysgenesis, infertility, heart & kidney anomalies and normal intelligence
• Pop Quiz

  -PKU: single gene autosomal recessive

  -Alcoholsim: multifactorial

  -Down syndrome: chromosomal-numerical

  -Turner syndrome: chromsomal-sex related

  -Familial hypercholestermia: single gene-autosomal dominant

  -Sickle cell anemia: single gene-autosomal recessive

  -Marfan syndrome: single gene-autosomal dominant

  -Albinism: single gene-autosomal recessive

  -Huntington's disease: single gene-autosomal dominant

  -Hemophilia: single gene-X linked

  -Color blindness: single gene-X linked

  -Schizophrenia: multifactorial