Karyotypes found in miscarriages up to 3 months of pregnancy
|
Abnormality
|
Explanation
|
Relative
Frequency
|
|
Aneuploidies
|
||
Monosomy |
One chromosome
not enough
i.e. 45 chromosomes |
16 %
|
Trisomy |
One chromosome
too many
i.e. 47 chromosomes |
54 %
|
|
Polyploidies
|
||
Triploidy |
3 times the
haploid number
i.e. 69 chromosomes |
20 %
|
Tetraploidy |
4 times the
haploid number
i.e. 92 chromosomes |
6 %
|
|
Translocations
|
||
Unbalanced translocation |
too much
of part of a chromosome
|
4 %
( at least ) |
Source: Adapted from figures published in 1975 by Boué and colleagues from France.