Chapter 15 – The Chromosomal Basis of Inheritance

Sex Determination

Sex-linked genes

Sex linked inheritance

• Must show sex chromosomes

• Hemizygous

X inactivation

• Barr body

Linked genes

Nondisjunction

• Aneuploidy

– Monosomy

– Trisomy

Down syndrome

Trisomies in sex chromosomes

• Klinefelter syndrome 47, XXY

• Jacob syndrome 47, XYY

• TriploX 47, XXX

Monosomy in sex chromosome

• Turner syndrome 45, XO

Chromosome structural abnormalities • Deletion

• Duplication

Chromosome structural abnormalities cont

• Inversion

• Translocation