Endogenous factors A<unk>  often arises due to endogenous factors, like errors in cellular replication and oxidative damage. This damage is rarely repaired imperfectly, but due to the high rate of germ cell division, can occur frequently. Endogenous<unk> s are more prominent in sperm than in ova. This is because spermatocytes go through a larger number of cell divisions throughout a male’s life, resulting in more replication cycles that could result in a DNA<unk> . Errors in maternal ovum also occur, but at a lower rate than in paternal sperm. The types of<unk> s that occur also tend to vary between the sexes. A mother's eggs, after production, remain in stasis until each is utilized in ovulation. This long stasis period has been shown to result in a higher number of chromosomal and large sequence deletions, duplications, insertions, and transversions. The father’s sperm, on the other hand, undergoes continuous replication throughout his lifetime, resulting in many small point<unk> s that result from errors in replication. These<unk> s commonly include single base pair substitutions, deletions, and insertions. Oxidative damage is another endogenous factor that can cause<unk> s. This type of damage is caused by reactive oxygen species that build up in the cell as a by-product of cellular respiration. These reactive oxygen species are missing an electron, and because they are highly electronegative (have a strong electron pull) they will rip an electron away from another molecule. This can initiate DNA damage because it causes the nucleic acid guanine to shift to 8-oxoguanine (8-oxoG). This 8-oxoG molecule is then mistaken for a thymine by DNA polymerase during replication, causing a G>T transversion on one DNA strand, and a C>A transversion on the other. Exogenous factors A<unk>  can also occur due to exogenous factors. Similar to somatic<unk> s,<unk> s can be caused by exposure to harmful substances, which damage the DNA of germ cells. This damage can then either be repaired perfectly, and no<unk> s will be present, or repaired imperfectly, resulting in a variety of<unk> s. Exogenous mutagens include harmful chemicals and ionizing radiation; the major difference between<unk> s and somatic<unk> s is that germ cells are not exposed to UV radiation, and thus not often directly mutated in this manner.
Germline mutation
Chromosomal fragile site
Germline mosaicism
Chromosomal translocation
Structural inheritance
Pseudodeficiency alleles
Aneuploidy
Non-Mendelian inheritance