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The following is a list of genetic disorders and if known, type of mutation and for the chromosome involved. Although the parlance "disease-causing gene" is common, it is the occurrence of an abnormality in the parents that causes the impairment to develop within the child. There are over 6,000 known genetic disorders in humans.
Because mitochondrial diseases (diseases due to malfunction of mitochondria) can be inherited both maternally and through chromosomal inheritance, the way in which they are passed on from generation to generation can vary greatly depending on the disease. Mitochondrial genetic mutations that occur in the nuclear DNA can occur in any of the ...
In X-linked dominant inheritance, when the mother alone is the carrier of a mutated, or defective gene associated with a disease or disorder; she herself will have the disorder. Her children will inherit the disorder as follows: Of her daughters and sons: 50% will have the disorder, 50% will be completely unaffected.
The first is that affected fathers cannot pass X-linked recessive traits to their sons because fathers give Y chromosomes to their sons. This means that males affected by an X-linked recessive disorder inherited the responsible X chromosome from their mothers. Second, X-linked recessive traits are more commonly expressed in males than females. [2]
Genetic causes of birth defects include inheritance of abnormal genes from the mother or the father, as well as new mutations in one of the germ cells that gave rise to the fetus. Male germ cells mutate at a much faster rate than female germ cells, and as the father ages, the DNA of the germ cells mutates quickly.
The term childhood disease refers to disease that is contracted or becomes symptomatic before the age of 18 or 21 years old. Many of these diseases can also be contracted by adults. Some childhood diseases include:
Paternal leakage – Although mtDNA is thought to be exclusively maternally inherited, paternal inheritance exists in a low frequency of 10 −4 relative to maternal inheritance in mice. [10] Hence, selection can act on male-specific deleterious mutations when they are paternally inherited, decreasing their frequency.
Y chromosomal DNA, paternally inherited, is used in an analogous way to trace the agnate lineage. Since the father's mtDNA is located in the sperm midpiece (the mitochondrial sheath), which is lost at fertilization, all children of the same mother are hemizygous for maternal mtDNA and are thus identical to each other and to their mother.