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Base pair: Two complemetary nucleotides which form hydrogen bonds between the two antiparallel DNA strands. Compound repeat: A compound microsatellite repeat is defined here as an occurrence of two or more microsatellites contiguously with intervening non-repeat sequence of <= 70 bp. Copy number: The number of times a particular motif has been tandemly repeated. Chromosomes: A structural unit of inheritence; condensed DNA protein complex visible during cell division. Deletion: Loss of a base or more in the repeat track leaving one or more base of the repeat unit intact, e.g. (ATT)3TT(ATT)2. Dinucleotide repeat/ dimer: Tandem repeat of two nuclotides in the same order, e.g. ATATATATAT. DNA: Deoxyribonucleic acid. A molecule made out of two strands in antiparallel orientation that are held together by hydrogen bonds, each strand being made up of a sugar (deoxy ribose), a phosphate group and one of four bases (adenine, guanine, cytosine or thymine). Exon: The region of a gene that encodes amino acids in a protein GC content: Guanine-Cytosine content of the genome of any given organism or any other piece of DNA or RNA Gene: One of the chromosomal units that transmit specific hereditary traits: a segment of the self- reproducing molecule, deoxyribonucleic acid Genome: The total genetic complement of an organism, i.e. an organism's complete set of DNA sequences. Imperfect repeat: A non-continuous repeat track, which is generated by a mutation (insertion/deletion/substitution) interrupting the continuity of the repeat unit., e.g. (ATT)3TT(ATT)2 Insertion: The presence of an odd base(s) disturbing the continuity of the repeat or an additional similar or odd base(s) within the repeat unit e.g. (ATC)3G(ATC)3, (TGA)3TCGA(TGA)2. Intron: A noncoding sequence of DNA that is initially copied into RNA but is spliced out of the final RNA transcript. Microsatellite: Tandem repeats of short simple DNA sequence, generally of 1-6 bases. Microsatellite Family: A microsatellite family consists of all those microsatellites occurring in a genome, which possess highly matching flanking sequences, the stringency of the sequence match being: percentage match=95% and alignment length= 85%. Mononucleotide repeat/ monomer: Tandem repeat of single base, e.g. AAAAAAAAA. Motif: Recurring pattern in a DNA sequence. Mutation: A disruption in the normal sequence of a DNA strand resulting in a varied sequence at the same position. Non-coding DNA: The segment of DNA that does not carry the information necessary to make an amino acid sequence. Nucleotide: One of the structural components, or building blocks, of DNA and RNA. A nucleotide consists of a base (one of five chemicals: adenine, thymine in DNA, uracil in RNA, guanine, and cytosine) plus a molecule of sugar and one of phosphoric acid Pentanucleotide repeat/ pentamer: Five nucleotides repeating in tandem to each other in the same order, e.g. AATTG AATTG AATTG AATTG. Point mutation: A change in a single base pair Repeat element: Short stretches of DNA with the capacity to move between different points within a genome. Repeat kind: Nature of repeat sequence, e.g. Perfect Repeat Imperfect Repeat Compound Repeat Repeat type: Based on the number of nucleotides in a motif,repeat type is classified into mono,di,tri.tetra,penta,hexa. Substitution: A mutation, where one base is changed for another base. Tetranucleotide repeat/ tetramer: Tandem repeat of four nucleotides in the same order, e.g. ATAC ATAC ATAC ATAC. Threshold: A length limit, below which DNA sequence is not considered for the analysis, e.g. Threshold of 6 bases means, 6 base and above is considered but not 5 base. Transition: A mutation that consists of the replacement of one purine by another purine or one pyrimidine by another pyrimidine, e.g. Adenine to Guanine, Thymine to Cytosine. Transversion: A mutation that consists of the replacement of a purine by a pyrimidine or vice versa, e.g. Adenine to Thymine. Trinucleotide repeat/ trimer: Three nucleotides repeating in tandem to each other in the same order, e.g. TAA TAA TAA TAA.
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