If a disease is X linked, how it is possible that a father with the disease would not pass it down to his children?
http://en.wikipedia.org/wiki/X-linked_recessive_inheritance
thank you
If a disease is X-linked, it means that the gene mutation causing the disease is located on the X chromosome. In general, males have one X chromosome and one Y chromosome, while females have two X chromosomes. In this context, the father with the disease would have one affected X chromosome and one unaffected Y chromosome.
When it comes to inheritance, there are a few possibilities depending on the sex of the parent and the child:
1. Father with the disease and son: Since the father passes his Y chromosome to his son, the son will not inherit the affected X chromosome and therefore will not inherit the disease.
2. Father with the disease and daughter: The father passes the affected X chromosome to his daughter. In this case, the daughter will be a carrier of the disease because she has one normal X chromosome from her mother to compensate for the affected X chromosome from her father. She may not exhibit symptoms but can pass the disease to her own offspring in the future.
3. Mother who carries the disease and son: If a mother is a carrier of an X-linked disease and passes the affected X chromosome to her son, he will have the disease.
4. Mother who carries the disease and daughter: If a mother is a carrier of an X-linked disease and passes the affected X chromosome to her daughter, the daughter, like her mother, will be a carrier of the disease.
It's important to note that these patterns of inheritance are generalizations, and specific genetic factors can modify the outcomes. Genetic testing and counseling can provide more accurate information on the likelihood of passing on a specific X-linked disease.