Cancer
uncontrolled growth of cells that have the ability to invade and spread to other parts of the body.
Carcinogenesis
the usually slow, gradual process of tumor development
Carrier
a person whoses genetic make-up includes a gene that causes disease,
but who does not have the disease
Cell
the basic building blocks that make up the human body. Each cell has a nucleus that contains a copy of the genetic material
Chromosome
a structure in the cell that contains genes. Humans have 46 chromosomes that are organized into 23 pairs. One of each pair is inherited from the father and the other is inherited from the mother. Forty-four of the chromosomes are autosomes. This means that they are the same for men and women. Two chromosomes are the sex chromosomes that determine if a person will be male or female. Males have an X and a Y chromosome, while women have two X chromosomes
Colon
an organ in the digestive system that helps the body to reabsorb water from the waste products of digestion. The function of the colon is important to help our bodies conserve water and control bowel movements
Colonoscopy
a procedure that is done to examine the colon. A thin tube is inserted into the rectum and used to view the colon from beginning to end. Small polyps may be removed during this procedure and biopsies can be taken from areas where cancer is suspected. This procedure is done with mild sedation to help prevent discomfort
DNA
the chemical building blocks of genes; made up of four "nucleotides"
whose sequence determines the function of the gene
Flexible Sigmoidoscopy
a procedure done to examine the lower portion of the colon. A thin tube is inserted through the rectum and used to view the bottom portion of the colon. Small polyps may be removed during this procedure and biopsies can be taken from areas where cancer is suspected
Gene
the set of instructions inside cells that determine a persons physical traits and also regulate who the body develops and functions
Genetic testing
technology used to detect genetic mutations that may cause a disease
Genome
the entire genetic make-up of a species. Currently, the Human
Geneome Project is being conducting to identify all human genes
Genotype
the genetic make-up of an individual
Hereditary
passed on through genes from one generation to the next
Karyotype
a picture of the chromosomes
Linkage
a statistical clue that a gene is at least partially responsible
for a disease
Locus
the physical location of a gene on a chromosome
Mapping
the process of finding the location of the gene responsible for a specific disease
Marker
a feature in the DNA that helps to specify a specific location on a chromosome. A marker may be a gene or it may be a unique area of DNA outside of a gene. Genetic markers are useful mapping the location of genes and for doing linkage. The markers themselves are not always the genetic feature that is causing the disease in a family, but looking for patterns of markers in the family can help determine the location of the disease causing gene
Molecular
refers to the basic building blocks of the genetic material, such as DNA, genes and the other chemicals involved with the functioning of genes
Mutation
an alteration in a gene that may cause disease or abnormal functioning of the body
Oncogene
a gene that when altered in certain ways helps transform normal
cells to cancerous cells
Pedigree
a drawing of a family tree
Penetrance
the proportion of people with a given genetic mutation that show symptoms of disease. A gene mutation is considered to be completely penetrant if it is always associated with illness, and incompletely penetrant if only some of the people with the mutation will develop the illness
Phenotype
an individual's physical and other characteristics determined
by his or her genotype
Registry
a database of individuals and families affected by a genetic
disorder that is used to study these conditions and identify other people who
may be at risk
Screening
the search for cancer in people without symptoms
Sibling
a sister or brother
Sporadic
disease that is apparently not hereditary
