DH 102 Exam 2 Lesson 5 Hereditary Diseases (guest speaker)
|Karyotype||A profile of an individual's set of chromosomes|
|List Autosomal Dominant Diseases (5)|| Achondroplasia (Achondroplastic Dwarfism)|
Polycystic Kidney Disorder- ADULT
|Achondroplasia (Achondroplasia Dwarfism)|| Fetus has defective cartilage formation resulting in abnormal bone development where bone replaces cartilage.|
Results in very short arms and legs, normal size trunk, large head and prominent forehead.
|Diabetes Insipidus|| Endocrine system disorder.|
Prevents water retention so marked increase in urinary output.
|Huntington's Chorea|| NS disorder |
Occurs during midlife
Causes degeneration of cerebral cortex and basal ganglia. Progressive chorea (abnormal muscular motion) and dementia
|Polycystic Kidney Disorder- Adult||During adulthood (after 30yrs.)|
Multiple cysts develop in both kidneys, gradually expand until normal kidney tissue is compressed and then destroyed.
Fluid filled grape like clusters grossly enlarge kidney eventually replacing kidney tissue.
Usually no signs / symptoms until much of kidney fxn is lost and renal failure occurs.
Nonspecific symptoms include- HTN, UTI, hematuria.
Kidney dialysis and transplant are often last resort before dying of total kidney failure
|Polydactyl||Infant born with extra fingers and toes|
|List Autosomal Recessive Diseases (5)|| Polycystic Kidney Diseases- CHILDREN|
Sickle cell anemia
|Polycystic kidney disease- children||Infantile disorder is rare. |
Occurs when 2 parents with recessive gene have child.
Infants usually stillborn or die within 2 years of life from kidney failure, congestive heart failure, or respiratory failure.
Fluid filled, grape like clusters of cysts formed in kidneys and compress normal kidney tissue causing tissue death.
|Cystic Fibrosis|| Defect of chromosome 7 (1 of 300 genes)|
Dysfunction of exocrine glands that affects multiple organ systems with production of very thick, viscous mucous and enzyme secretions.
Thickened mucous secretions block glandular ducts resulting in enzyme deficiencies and increased risk of respiratory diseases.
|Phenylketonuria AKA and def|| PKU.|
All children tested for this.
Born w/o an enzyme needed to convert amino acids (phenylalanine and tyrosine).
Increased levels of phenylalanine toxic to brain.
Cause severe mental retardation, NS abnormalities, poor balance and seizure activity.
Treatment- eliminating AAcids (phenylalanine) from diet.
|Sickle Cell Anemia||Primarily African Americans and middle eastern descent.|
Born with abnormal Hb that sickles or forms a crescent shape under hypoxic conditions.
Body destroys these blood cells resulting in jaundice and severe anemia.
Plug capillaries and blood vessels results in- severe pain in arms, legs, abdomen, seizures, strokes, MI, kidney and joint damage due to thrombosis, hypoxia, and ischemia.
No cure for disease and treatment aimed at relieving symptoms and pain during Sickle Cell Crisis.
1 in 625 of African Americans affected.
|Tay Sachs|| Primarily eastern Jewish origin. |
Enzyme deficiency essential for lipid metabolism.
Toxic levels of lipids build up in brain causing progressive mental and physical retardation.
Children usually die between ages of 3 to 5.
1 in every 3600 live births among Askenazic Jewish ppl.
|Sex linked hereditary diseases (3)|| Color blindness|
Duchenne's muscular dystrophy
|Color blindness||Transmitted on X chromosome |
Found only in males but CARRIED by females.
Gene is on X chromosome but normal vision gene is dominant, thus disease requires recessive gene on X to be passed.
Unable to distinguish certain colors due to abnormal receptors or cones in retina.
Problem usually between green and red.
|Duchenne's Muscular Dystrophy||Sex linked affecting young males.|
Metabolic defect in muscle cell membrane protein (dystrophin) leading to muscle degeneration and replacement with fat and fibrous CT.
Eventually affects all body muscles leading to respiratory and cardiac paralysis and death.
Signs and symptoms occur around age 3 and progressive to death in teens to early adulthood.
Different types of MS onset @ different ages, affect different parts, and vary in progression rates
|Hemophilia A|| Blood clotting disorder.|
Absence of factor 8- protein essential to clotting mechanism.
Any cut or injury leads to profound hemorrhage / bleeding.
Found in males and CARRIED by females.
|Chromosomal defects (6)|| Cri-Du-chat (Cat-Cry Syndrome)|
Trisomy 18 (Edwards Syndrome)
Trisomy 21 (Downs Syndrome)
Klinefelters Syndrome (polysomy X)
Turner's Syndrome (monosomy X)
|Cri-du-chat|| Deletion of short arm of 5th chromosome. |
Severe mental retardation, cat like cry, microcephaly, low set ears, failure to thrive and multiple organ malformations.
1 in 20K live births.
|Trisomy 13|| Tripling of the 13th chromosome|
Mental Retardation, severe hypertonia, seizures, microcephaly, malformed ears, cleft lip and palate, polydactyl, congenital heart defects, GI tract defects and polydactyl.
|Trisomy 18 AKA||Edwards syndrome|
|Trisomy 18|| Tripling of the 18th chromosome.|
Mental retardation, severe hypertonia, prominent occiput, low set ears, corneal opacities, 3rd and 4th fingers overlapped by 2nd and 5th fingers, finger syndactyl (webbing), heart, kidney, and GI abnormalities.
|Trisomy 21 AKA and def||Downs Syndrome.|
Tripling of 21st chromosome.
Mental retardation, hypotonia of muscle, flattened occiput, depressed nasal bridge, mongoloid slant to eyes (extra eyelid), large coarse protruding tongue, high arched palate, low set ears, broad, short fingers, simian crease across palms, congenital heart defects, defective immune system, vision problems.
Once in every 900 live births.
Once in every 600 women conceiving over age 40.
1% of all Down's are mosaic and have greater # of normal chromosomes raising their intellectual levels. (graduate, get professional careers)
|Klinefelter's Syndrome AKA and def|| Polysomy X|
Extra X chromosome.
Karyotype of XXY
Appears male at birth until puberty.
Puberty- breasts develop and female hair distribution
Abnormally tall, unusually long legs and arms, mentally retarded and sterile.
Testes- if present small and produce no sperm
|Turner's Syndrome AKA and def||Monosomy X- missing one sex chromosome|
Karyotype- 45X or 45 0X
Appears female at birth but ovaries don't develop.
No menstruation, nipples widely spaced on chest, no breast development at puberty, short statue, stocky build, thick wide neck.
Frequently have congenital heart defects especially AORTIC STENOSIS