NOT a mutation in Down's syndrome
(D) VNTR's# A Variable Number Tandem Repeat (or VNTR) is a location in a genome where a short nucleotide sequence is organized as a tandem repeat is associated with major psychiatric disorders.> Trisomy 21 also known by the karyotype 47, XX+21 for females and 47,XY,+21 for males.> The extra chromosome 21 material may also occur due to a Robertsonian translocation in 2-4% cases. In this situation, the long arm of chromosome 21 is attached to another chromosome, often chromosome 14.
Mosaicism
Robersonian translocation
Maternal non disjunction
VNTR's
Misc.