Karyotypes Chromosome Mutations Look at the karyotype for

§ Karyotypes are done by doctors to diagnose some genetic disorders

§ A normal human karyotype has 46 chromosomes (23 pairs): #1 -22 are called

RECALL…What is a mutation? § Any mistake or change in DNA sequence § Mutations

Chromosomal mutation: affects whole or part of a chromosome Gene mutation: Changes to the

Chromosomal Mutations § Change in # of chromosomes OR structure of the chromosome §

Can YOU spot the chromosomal mutation? ?

1) Deletion § Loss of all or part of a chromosome

2) Duplication § Produce extra copies of parts of a chromosome.

3) Inversion § Part of a chromosome breaks out and reinserts backwards.

4) Translocation § Part of a chromosome breaks off & attaches to another chromosome

5) Nondisjunction § Improper separation of homologous chromosomes during meiosis § Results in extra

Types of Nondisjunction § Trisomy~ 3 copies of a chromosome § Monosomy~ 1 copy

Down Syndrome – Trisomy 21 § Intellectual and developmental disabilities § may have heart

Trisomy on Sex Chromosomes § XYY Syndrome – Extra Y § XXX Syndrome –

Trisomy 13 (Patau syndrome) § Extra fingers or toes § Cleft lip or palate

Turner’s Syndrome 45, X § § § Webbed neck Infertile Swollen hands & feet

Chromosomal Mutations Videos § Chromosomal Mutations § Visualizing Nondisjunction

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Karyotypes & Chromosome Mutations

Look at the karyotype for the mutation

§ A karyotype is an organized profile of a person's chromosomes. § In a karyotype, chromosomes are arranged and numbered by size, from largest to smallest.

§ Karyotypes are done by doctors to diagnose some genetic disorders

§ A normal human karyotype has 46 chromosomes (23 pairs): #1 -22 are called autosomes #23 are called sex chromosomes

XX~ female XY~ male

RECALL…What is a mutation? § Any mistake or change in DNA sequence § Mutations can only be inherited if they occur in sex cells § Two types: Gene or chromosomal

Chromosomal mutation: affects whole or part of a chromosome Gene mutation: Changes to the bases in the DNA of ONE gene

Chromosomal Mutations § Change in # of chromosomes OR structure of the chromosome § Abnormality detected on karyotype § Five types

Can YOU spot the chromosomal mutation? ?

1) Deletion § Loss of all or part of a chromosome

2) Duplication § Produce extra copies of parts of a chromosome.

3) Inversion § Part of a chromosome breaks out and reinserts backwards.

4) Translocation § Part of a chromosome breaks off & attaches to another chromosome

5) Nondisjunction § Improper separation of homologous chromosomes during meiosis § Results in extra or missing chromosomes in gametes

Types of Nondisjunction § Trisomy~ 3 copies of a chromosome § Monosomy~ 1 copy of a chromosome Remember—normally have 2 copies of each

Can you spot the mutation?

Down Syndrome – Trisomy 21 § Intellectual and developmental disabilities § may have heart defects and respiratory problems

Look at the karyotype for the mutation

Trisomy on Sex Chromosomes § XYY Syndrome – Extra Y § XXX Syndrome – Triple X

§ What is the mutation? § Boy or Girl?

Trisomy 13 (Patau syndrome) § Extra fingers or toes § Cleft lip or palate (deformed lips) § Heart and brain structure problems § Die within 1 -2 years of age

§ What is the mutation? § Boy or Girl?

Turner’s Syndrome 45, X § § § Webbed neck Infertile Swollen hands & feet at birth § Heart defects

Chromosomal Mutations Videos § Chromosomal Mutations § Visualizing Nondisjunction