orderly presentation of family information using symbols

used to determine if trait is autosomal or carried on X or Y

dominant

inherited as an AUTOSOMAL DOMINANT but can be inherited on chromosomes 1, 9, 11, and 14

King George III had it

• Rare traits: most affected individuals have unaffected parents
• ALL children of two affected parents are affected
• the risk of an affected child from the mating of two heterozygotes is 25%
• Because it is autosomal: trait equal in males and females
• males or females can transmit the trait

• Affects glands producing mucus, digestive enz, and sweat
• AUTOSOMAL RECESSIVE. YEAH. READ THIS BECAUSE IT'S IN CAPITAL LETTERS. YOU WILL FAIL IF YOU DON'T KNOW THIS. ACTUALLY YOU'RE GONNA FAIL ANYWAYS BUT YOU'LL FAIL LESS HARD BY A COUPLE POINTS.
• CF: thick mucus clogs ducts to small intestine...malnourished
• also makes mucus in the lungs that clogs airways: often die of respiratory infections
• almost all children w.CF have phenotypically normal parents
• 1 in 2000 births in US white pop
• not as common in blacks or other backgrounds
• located to gene 7 defect in formation of CFTR protein

• high frequency among black pop
• production of abnormal hemoglobin causing cells to sickle and become weak
• also can cause blockage of vessels: strokes and paralysis
• resistant to malaria

• both heterzygotes and those with homozygous dominant genotype have an abnormal phenotype unaffected individuals carry two recessive alleles
• every affected individual should have at least 1 affected parent
• most affected individuals are heterozygotes with a homozygous (unaffected wife) each child has a 50% chance of being affected
• females = males
• to affected individuals may have unaffected children
• phenotype for homozygous ind is more severe than hetero

• Affected males produce all affected daughters and no affected sons
• a heterozygous affected female will transmit the trait to half of her children and sons and daughters will be equally affected
• twice as many daughters as sons are affected
• homozygous dominant female will give trait to all offspring
• HOW TO CHECK: if dad gives to more than daughters, is autosomal

• Hemizygous males and homozygous females are affected
• more males than females are phenotypically affected
• rare alleles-males almost exclusively affected
• affected males get their allele from their mothers and transfit to daughters but not to sons
• daughters of affected males are usually heterozygous and are unaffected but their sons have 50% chance of receiving the recessive gene

• red green = most common form. 8% of male pop in US
• inherited X-linked recessive traits
• blue color blindness = autosomal dominant. v. rare
• genes code for proteins in color vision cells in retina. normally bind to visual pigments that are sensitive to red, green or blue wavelengths of light. if the protein is broken they don't see color

• group of inherited diseases  characterized by progressive weakness and loss of muscle tissue
• there are both autosomal and X-linked forms

• most common form: 1/3500 males 
• symptoms start b/w 1&6 yrs and progress rapidly. age 12 in wheelchair. age 20 = dead due to heart and respiratory issues
• gene @ end of X chromosome
• codes for dystrophin: absent protein that is supposed to help cell cope with stress of muscle movement. w/o- cells go BOOM and die
• Becker = same thing but less bad

• Y-linked traits are passed directly from father to son
• all will be expressed because males are hemizygous for all genes on X chromosome
• three dozen Y-linked traits have been discovered
• one may regulate gene expression (what makes gender)

• does not develop until adulthood
• autosomal dominant disorder
• first expressed between ages of 30 and 50 yrs
• progressive dementia and twitching (nervous system breakdown)
• most affected individuals are heterzygotes...each child of affected parent have 50% chance

• autosomal dominant
• expressed later in life
• affected persons cannot metabolize porphyrin (component of hemogoblin)
• symptoms inclue: wine colred pee, intense phuysical pain, seizures, dementia, and psychosis
• King George III may have been affected

probability that a disease phenotype will be present when a disease genotype is present

example: if all individuals carrying gene for a dominant disorder have the mutant phenotype the gene = 100% penetrance

the degree that the phenotype is expressed

example: campodactyl--sometimes the pinky finger is fucked. other times it is not. it just kind of happens

• males cannot be heterozygous or homozygous for a trait because they only have one X chromosome
• considered HEMIZYGOUS for everything on the X-CHROMOSOME
• all Y-LINKED traits WILL be expressed

• causes a type of rickets or bowleggedness
• X-Linked dominant disease