click below
click below
Normal Size Small Size show me how
Patho 1 Quiz 3
Genetic Disorder/ Neoplasia/ RBC and WBC disorders
Question | Answer |
---|---|
Chromosomal Abnormalities | Abnormal number of chromosomes or alterations in chromosome structure. Mitotic or meiotic (crossing over) mistakes normally |
Aneuploidy | An improper chromosome number |
Nondisjunction is homologues failing to separate (Monosomic and trisomic gametes) | True |
Anaphase lag | one chromosome left out of new nucleus due to lag (Monosomic and normal gametes) |
Polysomy | too many chromosomes (more then 46) |
Abnormal Chromosome Structure most commonly make mistakes during crossing over | true |
Long arm | q arm |
Short arm | p arm |
Translocation (a/b/c) (d/e/f)------>(a/e/f) (d/b/c) | exchange of portions of nonhomologous chromosomes |
Inversion (a/b/c) (a/b/כ | removal and reverse attachment of portion |
Deletion (a/b/c/d/e/f) (a/b/c) | loss of chromosomal material |
Duplication (a/b/c/d/e/f/)x2 | extra copies |
Trisomy 21 | Down syndrome • Most common disorder • Mental retardation, protruding tongue, low-set ears, epicanthal folds, poor muscle tone, short stature • Associated with increased maternal age |
Trisomy 18 | Edwards syndrome • Less common and more severe than trisomy 2 |
Trisomy 13 | Patau syndrome |
Cri du Chat syndrome | deletion of short arm of chromosome 5 • Cry like cat |
Klinefelter syndrome | • XXY, XXXY and XXXXY • Sex male - extra X causes feminization • Lack of testosterone, testicular atrophy, infertility, tall, long appendages, feminine hair distribution, gynocomastia, high voice |
Turner syndrome | monosomy X (1/3000)• Female - no ovarian development • Age related • Short stature, webbed neck, fibrous ovaries, sterility, amenorrhea, wide chest, heart defects |
Multiple X females | common XXX • Normal appearance - menstrual abnormalities |
Double Y males | XYY - common • Taller than average |
Colorblindness is an X-linked recessive disorder. What would be the chance that two parents, a color-blind father and a carrier mother, have a daughter that is colorblind? | 1/4 |
Mendelian Single-Gene Disorders | • Alteration or mutation of single gene • Abnormal enzymes, structural proteins, regulatory proteins • Classified by: Location of defect and mode of transmission |
Mutation | any permanent change to DNA ( Frameshift and point mutations) |
Marfan syndrome | disorder of connective tissues • Tall, slender, long appendages • Arachnodactyly • Skeletal & joint deformities • Cardiovascular lesions - aorta & valves • Fibrillin 1 gene on chromosome 15 |
Huntington disease | neurologic function • Mental deterioration - involuntary appendage movement • Late acting lethal dominant • Chromosome 4 has abnormal number of CAG repeats |
Autosomal Dominant Disorders | • Mutation of dominant gene on autosome • Predictable inheritance patterns • Affected usually have affected parent • Unaffected don’t transmit • Offspring of affected - 50% chance • Rare heterozygote mating - 75% chance |
Autosomal Recessive Disorders | • Mutation of recessive gene on autosomes • Predictable inheritance patterns • Disease not apparent in parents of affected • Unaffected may transmit • Heterozygote mating - 25% afflicted • 50% chance carrier |
Albinism | lack of hair, skin & eye pigment • One form - lack of tyrosinase • Risk of sunburn, skin cancer, impaired vision, photosensitivity |
Phenylketonuria | inability to metabolize phenylalanine • Buildup of dietary phenylalanine in body - affects nervous system • Excess phenylalanine excreted in urine - musty odor • Manage with low phenylalanine diet |
Cystic fibrosis | most common single-gene disorder in Caucasians • Production of abnormally thick sections in lung and pancreas |
sex linked disorders | Duchenne MD, Hemophillias A&B, chronic granulomatous disease, G6P dehydrogenase deficit, agammaglobulinemi, others |
Hemophilia A | Bleeding disorder-lack of factor Vlll, Bleed easily and profusely, transmitted between royal families of Europe, Queen Victoria was the first carrier. |
Triple repeat mutations | Fragile X syndrome, Long repeating sequence of 3 nucleotides, Fragile X = 2300-4000 repeats |
Mitochondrial gene mutations | Passed during cell division, dysfunction in tissues with high ATP needs (nerves tissue, muscle, Kidney and liver) Only maternal transmission |
Genomic Imprinting | maternal and paternal chromosomes are different |
Prader Willi syndrome Mental Retardation | Deletion on paternal 15, short stature, obesity, poor muscle tone, hypogonadism (will eat nonstop) ataxia, laugh, inappropriately |
Angelman Syndrome Mental Retardation | Deletion on maternal 15, ataxia, laugh, inappropriately (lack of coordination) |
Polygenic Disorder | "geneticists nightmare" |
Teratology | study of developmental anomalies, |
Teratongens | agents that cause congenital malformations, stage of fetus at time of exposure |
Periods of fetal vulnerability | two stages: embryonic(9-12 wks) and Fetal(10wks-birth) |
Teratongenic agents | chemicals and drugs-long and varied list |
thalidomide | congenital limb defects |
alcohol | Fetal alcohol syndrome (group of anomalies) |
Rubella | fert-2wks |
Toxoplasmosis | protozoal eating undercooked meat, contact with cat feces |
Radiation | mutagenic and teratogenic |
The following are traits that cancer cells have, making them different from "normal" cells | immortality, lack of density dependent inhibition, ignorance of normal cell cycle checkpoints |
Neoplasia | New growth ( cell growth ) Tumor |
Cancer | associated with abnormal cellular gene expression |
Malignant | potential to kill (rapid growth) |
Benign | No potential unless in critical location, does not invade adjacent tissue or spread (slow growth) |
Anaplasia | lack of differentiated features (vary in size, shape, nuclei, abnormal mitosis |
Oma | Benign tumor (Chondroma) |
carcinoma and sarcoma | malignant tumor (osteosarcoma) |
Carcinoma | epithelial origin 90% of humans |
Sarcoma | mesenchymal origin (connective tissue) |
Proto-oncogenes | components of cell growth activating pathways. Proto-normal (controlled) Oncogene- cancer associated form of gene (uncontrolled) |
Categories of Oncogenes are: | Growth Factors, Receptors, Cytoplasmic signaling molecules, Nuclear transcription factors |
Oncogenes growth factors | small peptides secreted into extracellular space, bind to target cell, stem cells normally don't stimulate self, certain cancers secrete growth factors (self Stimulate) |
Oncogenes growth factor receptors | transmit growth factor into target, specific-binding leads to cell proliferation |
cytoplasmic signaling pathways | most components are unknown, normal- receptor to nucleus transfer |
transcription factors | triggered to drive cell to S (proto-oncogene) oncogene- over production of Tf or loss of Tf regulation Myc, jun, fos-common proto-oncogenes |
Proto-Oncogene to Oncogene 4 basic mechanisms | 1. oncogenes introduced into host by retrovirus 2. Proto-oncogene suffers mutation 3. DNA sequence that regulates proto-oncogene expression is damaged or lost 4. Error in chromosome replication |
Tumor Suppressor Genes | inhibit proliferation, loss of function may lead to tumor development, Rb gene- retinoblastoma |