Genetic Disorders

5 Categories Autosomal Dominant Autosomal Recessive Sex-Linked Chromosomal Co-Dominant

Autosomal Dominant – Caused when a protein is made by the body that should not be. Huntington’s Disease – Protein slowly wares away the nerves in the brain. Develop problems with coordination Dimensia Symptoms do not appear until age Patients wither to a vegetative state. Death occurs years after symptoms begin.

Tourette Syndrome – A protein causes too much dopamine to bond to motor neurons in the brain. Varies in severity. Unbelievable urge for body tics such as – Blinking, clearing throat, twitching head, and neck. Display OCD behaviors Dyslexia Coprolalia = Less than 20% (Involuntary Cursing). Echolalia = (Involuntary Mimicking). Sleep Disorders Mood Swings ADD/ADHD Treated with ant-drpression anti-anxiety medications.

Autosomal Recessive – A disorder caused by a missing protein on one or more autosomes. (non-sex chromosomes) PKU – (Phenylketoneuria) – Lacks a protein needed to break down amino acids found in dairy products. Amino acids build up in the brain. Causes brain damage and mental retardation. Early detection results in success of treatment.

Tay-Sachs- Person lacks a protein needed to break down fatty acids. Fatty acids become stored in the brain. Common in people of Jewish descent Blindness, Deafness, inability to communicate. Death occurs around age 4-5.

Sex-Linked – A disorder caused by a gene that is carried on the X-Chromosome. Color Blindness – Caused by a recessive gene. Colors are difficult to distinguish. One may be more intense than the other. Most commin is red/green deficiency. Affects more man than women. – 1 in 20 men - 1 in several hundred women

Hemophilia – Caused by one or more missing proteins designed to clot blood. People bleed longer. Must receive protein injections and platelet transfusions to clot blood. Susceptible to liver and joint damage.

Chromosomal – Disorders that occur through non-disjunction. Person ends up with too few or too many chromosomes. Down’s Syndrome – Trisomy 21. Mental Retardation Short stature Shorter life expectancy (50’s) Similar facial features (expressionless.) Eyes farther apart than normal. Ears lower on head. One line on hand rather than 2 at birth.

Turner’s Syndrome – Monosomy 23 Only have 1 sex chromosome (X) Every 1 in 2500 females affected. Most common of all chromosomal disorders. Short in stature Congenital heart defects. Hypothyroidism. Scoliosis and other skeletal malformations. Malformed kidneys Sterile Treated with growth hormones and hormones to bring on menstruation.

Co-Dominant – Disorder that results when both genes contain alleles that code for different proteins. Normal blood types are made this way. Sickle-Cell Anemia – Caused when the normal protein for making hemoglobin is present with the protein that makes the “sickle” shaped blood cell. Slows oxygen flow Clogs blood vessels. Increased risk of infection. Death is possible. Carriers are resistant to Malaria parasite. Common in African Americans and people of Hispanic descent.