| Term |
Description |
| Allele |
Individual variant versions of a gene. Individuals have two copies of each gene called alleles, one on each chromosome. |
| Chromosome |
A bundle of coiled DNA visible under a microscope. Humans have 22 pairs of chromosomes and two unpaired sex chromosomes. |
| DNA |
Deoxyribonucleic acid, the molecules that code for most life-forms on planet Earth. |
| EUA |
Examination Under Anesthetic, the clinical procedure used to identify tumors in the eyes of a person with retinoblastoma. |
| Exon |
Part of the DNA of a gene that codes for parts of the protein. |
| Gene |
A Sequence of DNA that codes for a particular protein. |
| Genetic Counselor |
Professional who is trained to discuss, interpret and advise people about genetic disease and present treatment options. |
| Heritable |
A mutation that can be inherited. A germline mutation. |
| Hypermethylation |
Extensive attachment of methyl groups to DNA at cytosine bases correlated with reduced transcription of the gene. |
| Intron |
Part of the DNA of a gene that does not code for protein. |
| Mutation |
Variations in DNA sequence of a gene that damage function and may cause disease. |
| PCR |
Polymerase Chain Reaction. A method (developed by Kary Banks Mullis in 1983) for amplifying a DNA base sequence using a heat-stable polymerase and two
20-base primers, one complementary to the (+)-strand at one end of the sequence to be amplified and the other complementary to the (-)-strand
at the other end. Because the newly synthesized DNA strands can subsequently serve as additional templates for the same primer sequences,
successive rounds of primer annealing, strand elongation, and dissociation produce rapid and highly specific amplification of the desired sequence.
Several variations have been developed for specific needs. For example, PCR may be combined with reverse transcription of mRNA to cDNA to amplify an
mRNA, forming so called RT-PCR.
|
| Polymorphism |
A variation in DNA sequence that does not disrupt genetic function or cause disease. |
| Proband |
The affected family member whose disease led to diagnosis of the family's mutation, usually the first affected person in a family. |
| Promoter |
Part of DNA in a gene that controls expression, like a switch that turns the gene on or off. |
| Retinoblastoma |
A rare cancer of the retina in children. Possible treatments include laser, freezing therapy, chemotherapy, radiation and surgery. |
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