An alteration of change in the genetic material, usually seen as harmful in clinical use.
Mutation
An abnormal number of chromosomes, occuring when an individual is missing either a chromosome from a pair or has more than two chromosomes of a pair.
Aneuploidy
The three types of Aneuploidy
Monosomy
Trisomy
Tetrasomy
A chromosomal disorder caused by the presence of all or part of an extra 21st Chromosome, named after John LangdonDown.
Down Syndrome (Trisomy 21)
A genetic disorder caused by thepresence of all or part of an extra 18th Chromosome, named after John H.Edwards.
Edward's Syndrome (Trisomy 18)
A syndrome in which a patient has an additional Chromosome 13.
Patau Syndrome (Trisomy 13)
A chromosomal abnormality in which all or part of one of the sex chromosomes is absent. This is described as a #23 monosomy nondisjunction.
Turner Syndrome "Gonadal Dysgenesis"
A condition in which human males have an extra X sex chromosome. This is otherwise known as 47, XXY or XXY Syndrome.
Klinefelter's Syndrome
This is the condition in which changes in the number of chromosomes in the living cells occur in multiples of odd numbers.
Euploidy
A chromosome aberration in which a part of a chromosome or a sequence of DNA is missing.
Deletion
A chromosome aberration where a potion of the chromosome is duplicated, resulting in extra genetic material.
Duplication
In this chromosome aberration, a portion of the chromosome has broken off, turned upside down and reattached. This is a rearrangement where a segment is reversed end to end.
Inversion
Translocation wherein genetic material is added from another chromosome.
Insertion
A chromosome disorder wherein a portion of one chromosome is swapped with another, thus exchanging segments.
Translocation
A chromosome whose arms have fused together to form a ring, denoted by the symbol r.
Ring Chromosome
This aberration is formed by the mirror image copy of the other arm as a result of losing one arm.