Human Disease through Heredity

Huntington Disease• Neurodegenerative Genetic Disorder that affects

muscle coordination and some cognitive functions

• The disease is caused by a dominant mutation on the gene called huntington

• Any child of an affected parent has a 50% chance of inheriting the disease. If both parents are afflicted the risk jumps dramatically

Cystic Fibrosis• Noted by difficulty

breathing which results from frequent lung infections that can be treated though not cured.

• Caused as a result of homozygous recessive gene

• Unable to produce enzyme (protein) to break down mucus

Cystic Fibrosis Heredity

Sickle-cell Anemia• A genetic blood disorder characterized by red blood

cells taking on an abnormal, rigid sickle shape• Individuals containing the homozygous recessive

form of the gene will develop the disease. However, individuals heterozygous for the gene are resistant to malaria

Sickle-cell Anemia Heredity

Down Syndrome• Caused by the presences of all or part of the 21st

chromosome• Associated with impairment of cognitive ability and

physical growth and a particular set of facial features

Karyotype – set of photographs of chromosomes grouped in order in pairs

Klinefelter’s Syndrome• Also known as XXY syndrome, A condition in

which males have an extra X sex chromosome.

Turner’s Syndrome• A chromosomal abnormality in which a part or

whole of a sex chromosome is missing. Characterized as having only one X chromosome