Pedigree tips for autosomal genetic diseases Determine whether the trait of interest is dominant (A) or recessive (a) Label the genotypes of homozygous recessive individuals (aa) Label every individual with a dominant phenotype with one dominant allele (A_) Offspring that are homozygous recessive received both recessive alleles from each parent Parents that are homozygous recessive always give a recessive allele to all of their children Never write a homozygous dominant genotype (AA). Only A?, Aa, aa

Fathers always give their only Y chromosome to their sons Fathers always give their only X chromosome to their daughters Sons receive their only X chromosome from their mother Males are not carriers Only mothers can give sons sex-linked traits on X Fathers or mothers can make daughters carriers Women showing the trait had a father with the trait, and a mother that was at least a carrier

Pedigree tips for sex-linked genetic diseases Assume the trait/disease is recessive Label the genotypes of every male: XAY or XaY. Do not write an allele with the Y. Label every female without the trait with one XAX- Females with affected male offspring are at least carriers Fathers with trait make daughters at least carriers Never write a homozygous dominant genotype (XAXA). Only XAX?, XAXa, XaXa.

Genetically inherited disorder Number disorder Genetically inherited disorder Autosomal # Sex Chrom. # Sex-linked Autosomal Pattern baldness RG colorblind Hemophilia Duchenne’s Muscular dystrophy Down Syndrome Trisomy, monosomy,tetrasomy Klinefelter Turner Ex. 47 XXX recessive codominant dominant Albinism Cystic fibrosis PKU Sickle Cell Huntingtons Achondroplasia Marfans