Karyotyping and Pedigree Analysis

Normal Human Karyotype  46 Chromosomes 44 autosomes + 2 sex chromosomes 44 autosomes + 2 sex chromosomes  Chromosomes matched by size, centromere position and banding pattern

Down Syndrome Karyotype Trisomy 21 Trisomy 21 1 in 800 births in USA 1 in 800 births in USA Intellectual disabilities Intellectual disabilities Heart, vision, & hearing defects common Heart, vision, & hearing defects common

Turner’s Syndrome Karyotype One X chromosome missing in females One X chromosome missing in females 1 in 2,500 births worldwide 1 in 2,500 births worldwide Short stature, webbed neck, heart defects, sterility, normal intelligence common. Short stature, webbed neck, heart defects, sterility, normal intelligence common.

Kleinfelter’s Syndrome Karyotype Extra X chromosome in males. (XXY) Extra X chromosome in males. (XXY) 1 of 1,000 males exhibit the disorder. 1 of 1,000 males exhibit the disorder. Small testicles and sterility. Breast enlargement and feminine body characteristics. Small testicles and sterility. Breast enlargement and feminine body characteristics.

Metafemale Karyotype XXX XXX 1 in 1000 live births. 1 in 1000 live births. Limited fertility. Limited fertility. Many show lower IQ scores and aggressive behavior. Many show lower IQ scores and aggressive behavior. Few physical signs, but often tall. Few physical signs, but often tall.

Pedigree Analysis Male Male Female Female Mating line Mating line Generations Generations Inbreeding line Inbreeding line Birth order Birth order

Pedigree Charts - Autosomes Autosomal Dominant – Trait appears in every generation Autosomal Recessive – Trait appears when two parents by chance carry the hidden allele.