Term
| How many chromosomes are there? |
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Definition
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Term
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Definition
All chromosomes except sex chromosomes
22 pairs are automosomes and 1 pair sex chromosomes
total is 23 pairs |
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Term
| How many strands of DNA are in each chromosome? |
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Definition
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Term
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Definition
variation of genes
An allele is a slightly different form of the same gene at a locus
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Term
| What are the four nitrogen bases? |
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Definition
| Adenine, Thymine, Cytocine, and Guanine |
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Term
| In which phase are chromosomes visible? |
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Definition
| metaphase or prometaphase |
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Term
| What are the two types of cell division? |
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Definition
| mitosis- somatic meiosis- gametes |
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Term
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Definition
Mitosis- Somatic cell
Meiosis- reproductive cells or gametes
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Term
| What are diploids and haploids? |
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Definition
Results in 2 daughter cells (diploids) with identical chromosomes and genes to the parent cell
/Each gamete (haploid) only has 23 chromosomes – one of each type of autosome and an X or a Y. |
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Term
| What are genotype, phenotype and karyotype? |
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Definition
Genotype – actual genetic makeup
Phenotype – which trait is expressed
Karyotype – complete picture of the chromosomes |
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Term
| What does HIPAA say about genetic info? |
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Definition
Prohibits denying coverage, limiting eligibility, or charging more based on genetic info
Limits exclusions for pre-existing condition
Genetic information alone, in absence of current disease, not considered a preexisting condition. |
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Term
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Definition
| the obligation of those who obtain information about individuals, either legitimately or illegitimately, to protect the privacy of that information. |
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Term
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Definition
| the moral obligation, usually under exceptional circumstances, to disclose information to at-risk relatives; this duty may require a health care professional to breach patient confidentiality if a person, other than the patient, is in clear and imminent danger. |
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Term
| What is patient autonomy? |
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Definition
| the obligation to respect the decision-making capacities of autonomous persons who have been fully informed with accurate and unbiased information. |
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Term
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Definition
| the right to control access to information about oneself. |
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Term
| What are nucleotides composed of? |
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Definition
| which are each composed of one sugar, one phosphate, and a nitrogenous base. |
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Term
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Definition
formed by DNA wrapped around histones (small positively charged proteins)
Unfolded DNA has "beads on a string" appearance.
Unit particle of chromatin |
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Term
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Definition
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Term
| Which nitrogenous bases bind together? |
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Definition
adenine (A) and thymine (T)
cytosine (C), and guanine (G). |
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Term
| What determines the genome sequence? |
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Definition
| The order of bases along a strand of DNA is what determines the genome sequence. |
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Term
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Definition
are chromosome pieces whose particular bases (e.g., ATTCGGA)
Gene – sequence of DNA in the genome that is required for production of a functional product.
Humans have an estimated 30,000 genes, with an average length of about 3,000 bases. |
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Term
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Definition
| determine how, when, and where the body makes each of the many thousands of different proteins required for life. |
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Term
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Definition
| messenger RNA (mRNA) is synthesized from the DNA template |
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Term
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Definition
Transfer RNA (tRNA) provides the link between the mRNA and the amino acid that correlates to the genetic code.
Translation – mRNA links with tRNA within the ribosome to form polypeptides. |
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Term
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Definition
| occurs within ribosomes (rRNA) in the cytoplasm. |
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Term
| Human chromosomes range in length from 51 million to 245 million base pairs. |
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Definition
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Term
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Definition
| Study of chromosomes – structure and their inheritance as applied to the practice of medicine. |
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Term
| What is the most common method for visualizing chromosomes? |
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Definition
| The most common method for visualizing chromosomes is G-banding with Giemsa stain. |
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Term
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Definition
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Term
| How are chromosomes classified? |
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Definition
by the of position of centromere
Metacentric – central centromere
Submetacentric – off center with arms of different lengths
Acrocentric – centromere is near one end |
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Term
| Describe what a p or q means and the numbering of chromosomes? |
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Definition
Two arms of the chromosome
p – short arm
q – long arm
Bands are numbered from the centromere and further subdivided by decimal points
Number at the top – how many bands are seen at this resolution |
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Term
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Definition
abnormal number of chromosomes due to an extra or missing chromosome
Always associated with physical or mental maldevelopment or both
Most common chromosomal abnormality |
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Term
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Definition
| only one of a particular chromosome |
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Term
|
Definition
three of a particular chromosome
Only viable in chromosomes 13, 18, 21, X & Y. |
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Term
| What are the two most common unbalances structural rearrangements of chromosomes? |
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Definition
Deletions – terminal or interstitial
Duplications – may result in partial trisomy |
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Term
| What are the three common balanced structural rearrangements of chromosomes? |
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Definition
Inversion, translocation, insertion
Inversion – two breaks and reconstituted with the segment inverted
Translocation – exchange of segments between 2 nonhomologous chromosomes
Insertions – segment removed from one chromosome and inserted into a different chromosome |
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Term
| What is a Robertsonian translocation? |
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Definition
Robertsonian translocations
Two acrocentric chromosomes fuse near the centromere with the loss of the short arms. |
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Term
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Definition
| individual has two or more cell populations with a different chromosomal makeup. |
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Term
| What is interesting about Prader-Willi and Angelman syndromes? |
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Definition
For some disorders, the expression of the disease depends on whether the mutant allele or abnormal chromosome is inherited from the father or the mother.
Prader-Willi syndrome – Abnl #15 from father
Angelman syndrome – Abnl #15 from mother |
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Term
|
Definition
Translocation – Robertsonian translocations
Two acrocentric chromosomes fuse near the centromere with the loss of the short arms. |
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Term
| What are the three major patterns of inheritance? |
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Definition
| Chromosomal abnormalities, single gene mutation, ad multifactorial. Also keep in mind of X-linked disorders and non-mendelian inheritance patterns |
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Term
| What are the most common types of chromosomal disorders? |
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Definition
Down's syndome (Trisomy 21)
Turner syndrome (45,X)
Klinefelter Syndrome (47,XXY)
XYY Syndrome (47,XYY)
Triple X Syndrome (47,XXX)
Chromosome Translocations or Inversions |
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Term
| What is mendelian inheritance? |
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Definition
punnett squares/ single gene disorders-classical
result of variants or mutations in genes |
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Term
| What types of inheritance affect males and females equally? |
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Definition
| Autosomal dominant conditions |
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Term
| What type of inheritance affects males more often? |
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Definition
| x- linked recessive disorders |
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Term
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Definition
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Term
| What are some non-mendelian inheritance patterns? |
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Definition
Mitochondrial
Triplet Repeat Expansions
Uniparental Disomy
Imprinting
Sporadic inheritance
Germline mosaicism |
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Term
| What is multifactorial (complex) inheritance? |
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Definition
| Interaction between 2 or more genes and non-genetic or environmental factors |
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Term
| What are some environmental factors? |
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Definition
| Prenatal environment (alcohol, drugs, nutrition, thyroid, maternal stress), Nutrition, Environmental toxins,Teratogenic drugs |
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Term
| What are the only trisomy disorders that are compatible with life? |
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Definition
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Term
| What is the only monosomy disorder compatible with life? |
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Definition
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Term
| What is the most common chromosomal disorder? |
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Definition
| trisomy 21- down syndrome |
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Term
| What is the greatest risk factor? |
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Definition
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Term
| What causes the phenotypical appearance in trisomy 21? |
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Definition
| Overexpression of genes on the extra chromosome |
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Term
| What are the common anomalies seen with chromosomal disorders? |
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Definition
| Growth retardation, mental retardation and congenital anomalies |
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Term
| Which diagnostic test for down syndrome has the lowest risk? |
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Definition
|
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Term
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Definition
| Percutaneous Umbilical Blood Sampling (PUBS) which is the confirmatory test |
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Term
| What is Edwards syndrome? |
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Definition
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Term
| Which type of pts are more affected? |
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Definition
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Term
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Definition
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Term
| What congenital anomolies are often seen? |
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Definition
| severe central nervous system malformations, eye and ear deformities, cleft lip and palate |
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Term
| What is cri du chat syndrome? |
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Definition
terminal or interstitial deletion of chromosome 5
Crying infants sound like a mewing cat – 1% of all institutionalized patients |
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Term
| What are also known as genome disorders? |
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Definition
Microdeletion & Duplication Syndromes
small deletions or duplications |
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Term
| What gene is responsible for the sexual phenotype of an individual? |
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Definition
| Gene SRY (sex-determining region on Y) |
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Term
| What is X-chromosome inactivation? |
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Definition
| in somatic cells of normal females one of the X chromosome is inactivated early in development. |
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Term
| How is it determined which X will be inactivated? |
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Definition
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Term
| What is an inactive X called? |
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Definition
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Term
| What are the most common sex chromosome disorders? |
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Definition
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|
Term
| What is Klinefelters syndrome? |
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Definition
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Term
| What is Turner’s syndrome? |
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Definition
(45,X) usually seen in Peds
The only viable monosomy in humans
XO individuals are genetically female, however, they do not mature sexually during puberty and are sterile. |
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Term
| When are single-gene disorder most often seen? |
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Definition
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Term
| What is the most common etiology of recessive disorders? |
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Definition
| the mutation impairs or eliminates the function of an enzyme |
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Term
| What is the recurrence risk for each sibling with autosomal recessive inheritance? |
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Definition
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Term
| What familial pattern is often seen in autosomal recessive inheritance? |
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Definition
| Phenotype typically seen in siblings but not in parents or offspring |
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Term
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Definition
| Iron overload causing fatigue, impotence, hyperpigmentation, diabetes, cirrhosis, cardiomyopathy; males |
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Term
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Definition
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Term
|
Definition
| Progressive pulmonary disease, exocrine pancreatic insufficiency, decreased male fertility, elevated sweat chloride concentration, and failure to thrive. |
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Term
| What is Tay-Sachs disease? |
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Definition
disorder of ganglioside catabolism caused by a deficiency of hexosaminidase A (an enzyme)
Lysosomal storage disease
most common in Ashkenazi Jews, French Canadians, Louisiana Cajuns, and Pennsylvania Amish |
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Term
| What familial pedigree pattern is seen in autosomal dominant disorders? |
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Definition
Appears in every generation – affected patient has an affected parent;
Exceptions – new mutation or poor penetrance
A child has a 50% risk of inheriting from an affected parent. |
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Term
| What is the risk to the child in AD disorders? |
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Definition
| A child has a 50% risk of inheriting from an affected parent |
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Term
| What percentage of hyperlipidemia disorders are caused by familial hypercholesterolemia? |
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Definition
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|
Term
| What are the typical cholesterol levels in FH? |
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Definition
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|
Term
| How significant is the risk in heterozygous pts with FH? |
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Definition
| Even heterozygotes have a high risk of coronary artery disease; Males 100% risk by age 70, Females 75% risk by age 70 |
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Term
| What is Huntington disease? |
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Definition
| progressive motor, cognitive, and psychiatric disorder |
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Term
| What type of mutation is seen in HD? |
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Definition
| Mutation is a triple repeat expansion – the more repeats the more severe the disease |
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Term
| What skin lesions are seen in neurofibromatosis? |
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Definition
| Café au lait lesions, neurofibromas |
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Term
| How is polycystic kidney disease inherited? |
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Definition
| Autosomal dominant inheritance |
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Term
| What causes achondroplasia? |
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Definition
| Caused by a gain of function mutation |
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Term
| How are x-linked recessive disorders passed through the family? |
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Definition
| Transmitted from affected male through his daughters to his grandsons who have a 50% chance of inheriting the disorder. Not transmitted from father to son |
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Term
| What disorders are associated with DMD in females? |
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Definition
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Term
| What clotting factor disorders are associated with hemophilia? |
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Definition
| Hemophilia A and B are X-linked disorders of coagulation caused by mutations of F8 and F9 genes, F8 – deficiency/dysfunction of clotting factor VIII, F9 – deficiency/dysfunction of clotting factor IX |
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Term
| What type of patients are seen with fragile X syndrome? |
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Definition
| Males with mental retardation and some dysmorphic facies, |
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Term
| What type of pts are seen with Rett syndrome? |
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Definition
| Females - Patients lose any speech or motor development particularly purposeful hand movements |
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Term
| What type of inheritance is seen in Prader-Willi syndrome? |
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Definition
| Uniparental Disomy with imprinting - developmental disorder due to a loss of parentally expressed genes (deletion of 15q11 to 15q13). |
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Term
| What principles of inheritance are seen with multifactorial (complex) inheritance? |
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Definition
| Close relatives are more affected than distant relatives. Demonstrate familial aggregation due to common disease-predisposing alleles |
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Term
| What is the pathology seen with venous thrombosis? |
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Definition
| genetic defects in coagulation factor inhibition and impaired clot lysis |
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Term
|
Definition
| immobility, pregnancy, oral contraceptives, surgery, advanced age, neoplasms |
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Term
| Which has a higher risk of venous thrombosis – factor V leiden or protein C deficiency? |
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Definition
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|
Term
| What is Hirschsprung disease? |
|
Definition
| congenital absence of parasympathetic ganglion cells in the colon – unclear inheritance – more common in males |
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Term
| Which type of diabetes is more closely related to genetics as evidenced by family studies? |
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Definition
|
|
Term
| What type of complications are seen in both types of diabetes? |
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Definition
| Vascular disease in many organs – eyes, limbs, kidneys, heart, brain etc. |
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Term
| What is the most common cause of dementia? |
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Definition
|
|
Term
| What pathology is seen in AD? |
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Definition
| beta-amyloid plaques, neurofibrillary tangles and cortical atrophy |
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Term
| What is the risk if a first degree relative has AD? |
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Definition
| Risk increases 3 to 4 times if a first degree relative has AD. 50% risk if MZ twin |
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|
Term
| What mental illnesses have a high familial concordence? |
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Definition
| Schizophrenia and bipolar disease |
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Term
| Which CAD risk factors have genetic components? |
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Definition
| Lipid metabolism, hypertension, coagulation disorders, inflammatory responses, arterial wall anatomy |
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|
Term
| What environmental factors have been implicated in CAD? |
|
Definition
| High fat, high sodium diet, obesity, smoking, sedentary life style |
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|
Term
| What neural tube defects are seen in families? |
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Definition
| Anencephaly and spina bifida |
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|
Term
| What has modified the incidence of NTDs? |
|
Definition
| The addition of folic acid to the diet of pregnant women |
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|
Term
| What is the concordance rate for MZ twins with cleft lip or palate? |
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Definition
|
|
Term
| What are the most common types of congenital cardiac defects? |
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Definition
| The most common types of congenital heart defects are flow lesions |
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Term
| What factors indicate an increased recurrence rate in complex inheritance? |
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Definition
| more than one affected relative, Severe form of the disease, Early onset of the disease, Affected relative is the opposite sex of normal risk, Consanguineous parentage |
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Term
| What causes tumors to form? |
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Definition
| normal controls over the cellular reproduction are lost; |
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Term
| What does malignant mean? |
|
Definition
| infiltrates nearby tissue and metastasizes through the bloodstream and lymphatic system to other areas of the body |
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Term
| What type of inheritance pattern is seen with most cancers? |
|
Definition
| complex/multifactorial inheritance pattern – “runs in families” and expression is effected by environmental factors |
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Term
| Which two types of genes are implicated in the pathogenesis of cancer? |
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Definition
| Oncogenes and tumor suppressor genes |
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|
Term
| Does cancer often occur after one mutation or multiple mutations? |
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Definition
| Usually multiple mutations are involved. |
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|
Term
| How may telomerase influence the pathogenesis of cancer? |
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Definition
| Telomerase enables the cell to continue dividing |
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|
Term
| Are most cancers somatic mutations or germline mutations? |
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Definition
| Most are somatic mutations and occur sporadically. |
|
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Term
|
Definition
| the development of new growth of capillaries to further supply nutrients and oxygen to the tumor; Vascular endothelial growth factor (VEGF) |
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Term
|
Definition
| vascular endothelial growth factor (VEGF) |
|
|
Term
| What other factors may be involved in the development of cancer? |
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Definition
| Mutation in stem cells, mutation in progenitor cells, dedifferentiation of cells, faulty tissue repair. |
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Term
| What are proto-oncogenes? |
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Definition
| Genes that normally trigger cell division when it is appropriate; When they are activated at the wrong time or tissue, they function as oncogenes |
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Term
| What are tumor suppressor genes? |
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Definition
| Tumor suppressor gene p53 “decides” whether a cell repairs DNA replication errors or dies by apoptosis. |
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Term
|
Definition
| If mutated a cell with mutated DNA is able to replicate and may cause cancer. More than half of all cancers involve a mutation or deletion of the p53 gene. |
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|
Term
| What are some newer approaches to treating cancer? |
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Definition
| Blocking hormone receptors, Stimulating cell specialization, Blocking telomerase, Inhibiting angiogenesis |
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Term
| What is prenatal screening used for? |
|
Definition
| tests fetuses for increased risk of a condition not based on family history |
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|
Term
| How many genetic disorders does FL recommend for newborn screening? |
|
Definition
| 34 conditions and congenital hearing loss |
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|
Term
| What is the most common type of genetic analysis performed? |
|
Definition
| Polymerase Chain Reaction (PCR) |
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|
Term
| What is the Western Blot test useful for analyzing? |
|
Definition
| most commonly used technique for examining one or more proteins |
|
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Term
|
Definition
a process in which an individual or family makes a decision based on relevant information.
a process in which an individual or family makes a decision based on relevant information. |
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|
Term
| What is the most common form of dwarfism? |
|
Definition
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