SCT 2: DNA technologies and molecular diagnostics

Cloning

production of many identical copies of a DNA sequence, a cell, or a whole organism.

cDNA:

complementary DNA – a DNA copy of an RNA, made by reverse transcriptase

Complementary:

of two nucleic acid strands, having the ability to form sufficient base pairs to establish a stable duplex. Also used to describe the sequences of complementary strands.

Reverse transcriptase:

An enzyme, often of viral origin, that makes a DNA copy of an RNA template; an RNA-dependent DNA polymerase.

Next-generation (massively-parallel) sequencing:

a collection of methods for very high-throughput DNA sequencing by sequencing many molecules in parallel.

Single nucleotide polymorphism (SNP):

a position in the genome where two or occasionally three alternative nucleotides are common in the population. May be pathogenic or neutral. The dbSNP database lists human SNPs, but includes some rare pathogenic variants and some variants that involve two or more contiguous nucleotides.

Exome:

the totality of exons in a genome

Genome:

the total set of different DNA molecules of an organelle, cell, or organism. The human genome consists of 3.1 × 109 bp of DNA divided into 25 molecules, the mitochondrial DNA molecule plus the 24 different chromosomal DNA molecules.

OMIM:

the Online Inheritance in Man database at https://www.ncbi.nlm.nih.gov/omim .

PMID:

PubMed identifier, a unique number, currently eight digits in length, assigned to a biomedical literature article at https://www.ncbi.nlm.nih.gov .

Conserved sequence:

a sequence (of DNA or sometimes protein) that is identical or recognizably similar across a range of organisms.

Pathogenic:

causing disease.

mtDNA:

mitochondrial DNA—DNA of the 16,569 nt mitochondrial genome

Pharmacogenetics:

the study of the influence of genetic factors on the response to drugs. Divided into pharmacokinetics (the absorption, activation, catabolism, and elimination of a drug) and pharmacodynamics (the response of a target organ or cell to a drug).

Polymorphism:

strictly, the existence of two or more variants(alleles, phenotypes, sequence variants, chromosomalstructure variants) in the population at frequencies too high to be maintained by recurrent mutation. Looser usages among molecular geneticists include: (1) a sequencevariant present at a frequency >1% in a population; (2) anonpathogenic sequence variant, regardless of frequency. .