Genetics & Hereditary Disorders

Genetics & Hereditary Disorders

Genetics 

Heredity refers to the passing on of characteristics

 DNA

is deoxyribonucleic acid, our hereditary material

 

DNA is made up of sugar, phosphate, and 4 nitrogenous bases: o Adenine, thymine, guanine and cytosine



Genetics 

DNA has to replicate before cell division, because DNA is found in the nucleus





Chromosomes are DNA molecules curled around histone proteins



 Everyone

cells

has 46 chromosomes in each of their



A

gene is a sequence of DNA that contains instructions to make proteins

Gender Chromosome

pairs 1-22 work on the function or development of body

 Pair

23 determines sex

 Two

X chromosomes means it’s a girl

 A 

boy has X and Y chromosomes

Disorders & Replication Genes

accomplish important tasks, and if there is a malfunction while DNA replication, a disorder will occur in the baby developing in the womb During cell division, the chromosome may fail to split and therefore, a daughter cell will: o Have an extra chromosome, OR o Have a missing chromosome

Down Syndrome A

disorder caused by an extra chromosome 21

 Causes

severe mental retardation

 Occurs 

in every 1 out of 800 babies

Health Issues and DS  Almost



half of DS pts will have a congenital heart defect

 Many



babies with DS are rejected by the body and are therefore miscarried

 About



92% of women who find out they are carrying a DS baby will abort

 Many

 

children with DS also suffer from hypotonia

Behavior Issues and DS As

DS children grow into their late teen years, they will begin to realize their limitations and grow frustrated and angry

 DS

children tend to be stubborn.

Children with DS

Fragile X Syndrome  Most

 A

 X



common cause of inherited mental retardation(including autism) fragile X chromosome may break and damage gene chromosome houses FMR1 which produces a protein(FMRP) important to brain development & cell communication

 People

FMRP

with FXS have a deficiency in

Inheriting Fragile X A

person may get this disorder without his or her parent’s having it, but a male relative will most likely have it.

 Women

tend to be the carriers and mainly affects men.

 Causes

seizures, severe retardation, growth problems, memory impairment.

Fragile X in kids Strategies

for children with ADHD tend to be as helpful for those with FXS o Children with FXS can’t sit down and listen for long amounts of time. o Like children with DS, children with FXS may take years to be potty trained. o Teens and adults with FXS can become angry/violent and will be put on medication if misbehavior persists.

Hemophilia  Hemophilia

refers to a group of bleeding disorders in which it takes a long time for the blood to clot. (health.google.com)



 Type

A and Type B have similar symptoms, but are different gene mutations

  Mutation

in F8 gene causes type A

  Mutation 

in F9 gene causes type B

Hemophilia A & B Type

A is caused by a mutation in the F8 gene which causes a protein called coagulant factor VIII(8)

 Type

B is caused a mutation in the F9 gene which causes another protein called coagulant factor IX(9)



This 

is an X-linked disorder

Treating Hemophilia Starts

at birth

 Treated

by replacing coagulant factors usually through IV



http://www.youtube.com/watch?v=nnvOS 



Fin!