Term
| Alkaptonuria (Cause, Symptoms, Mode of Inheritance, Pleiotropic) |
|
Definition
Cause: Metabolic Disorder, missing homogentisic acid oxidase, build up of melanin in urine, nails, skin, cartilage Urine when exposed to O2 turns black.
Symptoms: Blackened Diaper, Hearing Loss, Blue Ears. Back spasms by age 15 & spine degenerates.
Modes of inheritance: Auto recessive
Pleiotropic: 1 gene with many phenotypic effects. |
|
|
Term
| Multiple Alleles in Carrier Testing (Illness examples) |
|
Definition
A mutation can occur at a variety of alleles and they would all cause the same effect.
Phenylketonuria (PKU)
Cystic Fibrosis (CF) |
|
|
Term
|
Definition
Seen in enzyme deficiencies
Aa - must meet necessary threshold level for good health.
Examples: Tay Sachs Disease
Familial Hypercholoesterolemia |
|
|
Term
|
Definition
| Where the contributions of both alleles at a single locus are clearly visible and do not overpower each other in the phenotype. Example: ABO blood type |
|
|
Term
|
Definition
| One gene masks or otherwise affects another genes phenotype. Example: Bombay Phenotype: hh genotype affects ABO expression |
|
|
Term
|
Definition
All or no expression of a genotype of indiv.
Affects % of population
Examples: Huntingtons Disease: Hh: Complete penetrance
Polydactyly: Pp incomplete penetrance in pop. Variable expressivity among indiv. |
|
|
Term
|
Definition
One gene causes many phenotypic effects.
Example: Porphyria variegata: (auto dom)caused by an overproduction of porphyrans which can result in many symptoms including nervous system and skin damage.
Murfan Syndrome: (auto dominant)
Defective fibrillin. Accum. in eye lens, aorta, limb bones, fingers, ribs.
Symptoms include dislocated lens, long limbs and fingers, and a weakened aorta. |
|
|
Term
|
Definition
Environment causes trait that appears like a genetic trait.
Examples: Limb deformities caused by thalidomide in the womb.
Cleft Palate caused by smoking, medicines, infections, or pesticides. Blotchy Skin (darkened fingers and ears) Caused by the maternal use of hydriquine cream. AIDS: caused by maternal blood transfer to fetus. |
|
|
Term
|
Definition
Different genes producing same phenotype.
Examples: Hearing loss: 132 forms, many genes are auto recessive. Cleft Palate. Albinism. Blood Clot Disorders: 11 different biochem reactions. Long QT Syndrome: different proteins involved in K channels in heart muscle. |
|
|
Term
|
Definition
Each mitochondrion has multiple copies of chromosome. Naked DNA with no introns, or crossing over events. Maternally inherited.
Has a higher mutation rate than nuclear DNA due to a lack of DNA repair enzymes, and O2 free radicals that cause damage.
1000bp long control region for start of replication.
37 genes unique to mitochondria |
|
|
Term
| 37 genes unique to Mitochondria |
|
Definition
22tRNA genes
2rRna genes
13 genes involved in cell respiration |
|
|
Term
|
Definition
Mitochondrial Myopathy: lack enzyme involved in ATP production, muscle fatigue results.
Leberoptic Atrophy: impaired vision, central portion of optic nerve slowly degenerates
MELAS: mutated tRNA gene, many symptoms occur
To prevent maternal inheritance: a donors mitochondria can be ooplasmicly transferred in vitro, and than implanted in the uterus for development. |
|
|
Term
|
Definition
Mutation in some but not all mitochondrial chromosomes. Symptoms are dependent on the number of maternal mitochondria with the symptoms.
Examples: Leigh Syndrome: affects enzyme that directly produces ATP. Mild impairment of peripheral vision to blindness.
Leberoptic Atrophy: Increased symtpoms with inc. accum. of bad mitochondria. |
|
|
Term
| MtDNA as Identification Tool |
|
Definition
| Link suspects to crime. Identify war dead. Investigate historical records. Perform ancestral studies. |
|
|
Term
|
Definition
WAS gene with 2 deletions - X linked
Boys with poor clotting, eczema, diarrhea, ear infections, pneumonia.
Died at 4,8, and 18 month from digestive tract bleeding. Survivors end up with blood borne cancers and autoimmune disorders. Need stem cell bone marrow transplant. |
|
|
Term
|
Definition
Autosomal Dominant
Mutated Wnt4 gene
Symptoms: XX chromosomes.
Breasts and pubic hair at age 12 but no menstruation, oddly positioned ovaries, no uterus or vagina. Normal female hormones, elevated male hormone levels. |
|
|
Term
|
Definition
| Sex determining region of the Y chromosome. Presence at week 6 of pregnancy determines gender. |
|
|
Term
|
Definition
231 protein encoding genes.
Many palindromes throughout 95% of chromosome can loop out during meiosis and cause deletions. Keeps on getting smaller. |
|
|
Term
|
Definition
5% of Y chromosome
63 genes, also seen in X chromosome.
Regions of recombination with X chromosome. |
|
|
Term
| MSY (Male specific region) |
|
Definition
Part of Y chromosome.
10-15% X transposed sequences (99% identical to X chrom. - genes are scarce)
20% X-degenerate DNA sequences
Rest are amplicons (palindromes)
Genes with many repeats - specify protein segments that combine in different ways.
SRY (sex determining region) |
|
|
Term
| Androgen Insensitivity Syndrome |
|
Definition
Mutation in an X chromosome gene
Absence of receptors for testosterone
XY looks female. |
|
|
Term
| Male Pseudohermaphroditism |
|
Definition
| XY but block in testosterone synthesis from testes results in no male structures. At puberty the adrenal gland produces testosterone and mascularization occurs. |
|
|
Term
| Criteria for an X-linked recessive trait |
|
Definition
1. Always expressed in male
2. Expressed in female homozygote but rarely in heterozygote.
Passed from heterozygote or homozygote mother to affected son.
Affected female has an affected father and a mother who is affected or a heterozygote. |
|
|
Term
|
Definition
X linked recessive
Enzyme deficiency
Blocks removal of cholesterol from skin
Upper skin layers cannot peel off
Skaly skin results.
Female carrier produces half of enzyme.
Only seen in men phenotypically. |
|
|
Term
|
Definition
X linked recessive
8% males in Europe are C.B.
4% males in Africa
.4% of females in both areas are C.B. |
|
|
Term
|
Definition
X linked recessive
3 weeks for a cut to heal due to a lack of clotting factor 3. Whole transfusions can cause kidney failure.
Treated by gene therapy. |
|
|
Term
|
Definition
Rare
XA Xa recessive allele offsets phenotype a bit.
XA Y more severe.
Examples: IP and CGH |
|
|
Term
|
Definition
X-linked recessive
Poor sense of smell and small gonads |
|
|
Term
|
Definition
75% of genes on one X chromosome in early embryonic development become inactive.
Other 25% expressed in diff degrees in diff women.
Inactivation is reversed in germline cells, than reactivated after fertilization.
X-Inactivation Center (XIST)
XIST RNA (25kb) binds to X chromosome, causing meyelination at CG sequences preventing transcription. |
|
|
Term
| Consequences of X-Inactivation |
|
Definition
| Anhidrotic Ectodermal Dysplasia: no sweat glands in patches of skin. |
|
|
Term
|
Definition
XHXh hemophilia carrier: may have a mild case if XH is inactivated and cannot make clotting factor.
Lesch-Nyhan Syndrome
Lacking HGPRT causing cerebral palsy
Test mother to find if she is a carrier. |
|
|
Term
| Craniofrontonasal syndrome |
|
Definition
| Abnormal fusing of cranial bones caused by heterozygote X-linked alleles. |
|
|
Term
|
Definition
Only affects one of the genders; may be autosomal or X-linked.
Preeclamsia: high B.P. close to birth. Caused by fathers gene in placenta. |
|
|
Term
|
Definition
| An allele is dominant in 1 gender and recessive in the other |
|
|
Term
| Disorders caused by Disrupted imprinting |
|
Definition
Prader-Willi Syndrome (paternal deletion causes obesity and no sexual maturity)
Angelman Syndrome- Maternal deletion causes mental retardation and poor muscle coordination.
Diabetes, autism, Alzheimers, Schizophrenia, male homosexuality others. |
|
|
Term
|
Definition
>600 genes imprinted
Specific genes imprinted from the paternal or maternal side only due to the silencing of the other copies by methylation. |
|
|
Term
|
Definition
Multifactorial (environment and genetics) trait with 3 genes associated. Additive risk per gene.
4-12 weeks into gestation develops
4 mo lip surgery
1 yr palate surgery
7 orthodontist work
10 bone from hip to palate
16 nose job |
|
|
Term
|
Definition
Influenced by multiple genes, rare
Variation is continuous not discrete
Effect of genes is additive
Quantitative Trait (Loci) - continuously varying phenotype |
|
|
Term
|
Definition
Influenced by multiple genes and the environment, many.
Examples: Multiple Schlerosis - 5 genes - increased risk with number of contributing alleles and with the right environmental cue
Height: Increases over generations due to better nutrition and overall health
Fingerprints
Skin Color |
|
|
Term
| Multidrug-resistant Gene (MDR) |
|
Definition
Pumps toxins (medicines) out of cells
Allele in 61% of A.A. and 23% of E.A. |
|
|
Term
|
Definition
| To predict a chance that a multifactorial trait will occur in an individual; based on incidence in a specific population |
|
|
Term
|
Definition
| A rate at which a certain event occurs e.g. # of new cases diagnosed per year in pop. |
|
|
Term
|
Definition
| Proportion or # of individuals in population that have a disorder at a specific time. |
|
|
Term
|
Definition
| Estimates the proportion of the phenotypic variation in a population due to genetic differences |
|
|
Term
| Coefficient of Relatedness |
|
Definition
| Proportion of genes that 2 people related in a certain way share. |
|
|
Term
|
Definition
| Shared envir. and 50% of genes |
|
|
Term
|
Definition
| Identical genotype and shared environ. |
|
|
Term
|
Definition
| Percentage of MZ pairs in which both twins express the trait. |
|
|
Term
| Single Nucleotide Polymorphism (SNP) |
|
Definition
Site polymorphic if allele is present in >1% of population.
Can detect DNA sequences that are inherited with polygenic traits
On average between 2 people, 1 SNP every 1000 bases = 3 mill diff. |
|
|
Term
|
Definition
| Seek correlations between SNP patterns and phenotypes in large groups of indivs. |
|
|
Term
|
Definition
Inflammed small intestine
11 SNPs shared in 235 families w/ affected members |
|
|
Term
|
Definition
3 genes: Stress hormone receptor gene
2 genes coding for serotonin availability.
Flu-like onset, last 6 months
Severe physical illness or emotional trauma followed by fatigue
Too much serotonin (induces sleep)
Too little cortisol (stress hormone) |
|
|
Term
|
Definition
| Abilities, feelings, moods, personality, intelligence, how one communicates, copes with rage, handles stress. |
|
|
Term
| Behavioral Disorder classes |
|
Definition
| phobias, anxieties, dementia, psychosis, addiction, mood alteration |
|
|
Term
|
Definition
Hard time staying still and controlled
Affects 5% of children and adolescents; 2-3% adults
(H) .6-.9 in diff pops.; wide range indicates large envir. component
Siblings of affected child show 3-5X greater risk
Twin studies indicate 80% heritability
Sites on chrom 7,15,16 and 17
Low dopamine levels due to poor transporter and/or receptor proteins. |
|
|
Term
|
Definition
Does not speak or interact with others
Comfortable only with restricted or repetitive behavior
~11/10000 incidence
Sibling risk is 2-4%
High heritability
14 different chromosomes with risk raising genes
Probably different disorders with similar symptoms. |
|
|
Term
|
Definition
Anorexia Nervosa: See self as overweight. Starve, exercise, use laxatives. Can starve to death. Can control eating.
Bulimia: Binge and purge to maintain weight. Induced vomiting. Can't control eating. |
|
|
Term
|
Definition
Percieves self as overweight and intentionally starves. Woman in US 5% risk. Risk of mortality is 15-21% highest of any psychological disorder. 2.5% risk of 2nd eating disorder
10% of cases are males
.5-.8 heritability
Genes control appetite, dopamine and serotonin levels may be mutated.
60 SNPs among 2000 families where 2 or more members have anorexia |
|
|
Term
|
Definition
4 out of 5 stages of sleep have hereditary component
5th stage more environmentally influenced |
|
|
Term
| Narcolepsy with Cataplexy |
|
Definition
Falls asleep suddenly with periods of muscle weakness.
.02-.06% general population in U.S. and Europe 1-2% risk with 1st degree relatives
25-31% concordance with MZ twins
Mutated hypocreatin (neuron receptor) does not arrive on cell surface, thus unable to receive awakeness signal. |
|
|
Term
| Familial advanced sleep phase syndrome (FASPS) |
|
Definition
Autosomal dominant
1 pt mutation, protein unable to bind with phosphate. Cannot pass on signal that synchronizes sleep-wake cycle |
|
|
Term
| Heritability of Intelligence |
|
Definition
Declining environ. impact with age
Preschoolers: H = .4
Adolescents .6
Adults .8 |
|
|
Term
| Drug Addiction: Tolerance and Dependence |
|
Definition
Compulsively seeking and taking a drug despite knowing its adverse effects.
Tolerance: need to take more of drug to achieve same effect as time goes on.
Dependence: onset of withdrawal symptoms when a person ceases taking a drug. |
|
|
Term
| Proteins involved in Drug Addiction |
|
Definition
Biosyn pathways of neurotransmitters in presynaptic neuron
Neurotrans. reuptake transporters
Cell surface receptors
Signal transduction pathway in postsynaptic neuron
Dopamine D2 receptor gene as one possible cause
Many genes associated with above list. |
|
|
Term
|
Definition
Extremes of normal behavior
Affects 6% of U.S.
Possibly chrom. 4/10/18/22 |
|
|
Term
|
Definition
1% population
Months of depression alternating with mania
Lowered serotonin levels (SSRIs used) |
|
|
Term
|
Definition
Loss of ability to organize thoughts or perceptions. Onset early adulthood- delusions hallucinations
Affects 1% of worlds pop. H = .8
Multifactorial trait
Mutation on chrom. 5 deletion on chrom 22
Excessive dopamine seen.
Environmental risk factors. |
|
|
