Abnormalities in the genes or chromosomes can cause variousgenetic disorders and diseases. Half of our genes come from our mother and theother half we got from our father. That’s how genetic material is passed fromone generation to another. Mutations of some genes can be also passed out tothe children and these are inherited mutations. Some genes are defected andwhen the child gets such duplicated genes he/she is inheriting the disease thatgene is carrying.
There are many diseases that could be inherited, including:hereditary multiple exostoses, cystic fibrosis and sickle cell anemia.
Dominant and Recessive
There are the dominant and recessive genetic traits. In the caseof recessive genetic traits it means that something won’t be expressed in aperson’s life but it will stay dormant (latent). Dominant genetic traits willexpress themselves in the person’s life immediately.
There are also autosomal dominant and autosomal recessivepatterns of inheriting the genetic diseases. Autosomal dominant disorders willbe expressed even if there is only one mutated copy of that gene. Children have50% chances to inherit these diseases form they parents. Such diseases areHuntington’s disease and hereditary non-poluposis colorectal cancer.
Autosomal recessive pattern disorders need two copies (onefrom each parent) to be expressed as the disease. Sickle cell anemia and cysticfibrosis are autosomal recessive diseases.
Mutations of X Chromosome
Mutations can happen in genes on the X chromosome. When thathappens in a man, and it’s a dominant disorder his sons probably won’t inheritthat medical problem. But, if this man has a daughter or daughters, they willinherit it for sure. Man suffering from X recessive disorder will pass a singlecopy of the disorder to his daughters, but his sons won’t be affected by it. Womanhaving a dominant X linked disorder has a chance of 50% to pass it onto herchildren, either sons or daughters. Some of the well known X linked dominantdisorders are Aicardi and Rett’s syndromes, while color blindness andhemophilia type A are recessive X linked disorders.
Mutations of Y Chromosome
There are fewer disorders associated with the mutations ofgenes on the Y chromosomes, since it is much smaller than X chromosome and don’thave so many genes. Male infertility is one of the disorders connected with mutationon Y chromosome. These disorders can happen only in men, because only men havethe Y chromosome, and the only way they could inherit these disease is fromtheir father.
Other Genetic Diseases
Mutations on the mitochondria might also cause geneticdiseases. These disorders can be inherited only from our mother. Mitochondrial encephalopathyand Leber’s hereditary optic atrophy are the examples of inherited mitochondrialdisorders.
Polygenetic inheritance or mutations in several genes canalso be responsible for genetic disorders. Sometimes obesity, diabetes, heart-relatedproblems, arthritis or cancers can be explained by this pattern of inheritance.