"My kid has a genetic disorder "
I am sorry to hear that. This will make a good teaching tool, however.
How do you think your kid got this genetic disorder? He inherited it from you and his mom, right? It is probably that the gene that gives him this disorder is two recessive alleles for the disorder. A person without the disease would probably have neither of the alleles for the disorder.
You and your wife probably have one allele each and another allele that does not carry the disorder, but may be different in some way. Thus in your family there are three alleles max.
In most families there is probably just one allele or perhaps two. The recessive alleles that gave your kid the disease are harmful and will reduce the liklihood of procreation (because the death rate prior to maturity is probably slightly higher). Over thousands of years, the number of disease alleles will be reduced in the population. This change in frequency of alleles in the population is evolution by natural selection.
The disease allele was probably formed by some sort of mutation in one individual many years ago and spread as a recessive throughout the population. As it becomes more frequent (evolution) the chances of mating with someone with another recessive increases. This causes the expression of the disease to increase, but only 25% of a heterozygous cross will produce children with the disease. 50% will be carriers of the recessive and 25% will have no disease allele.
This is why it is dangerous to marry someone too closely related to you. There are more chances of the recessive genes being expressed and genetic diseases in the offspring.
In any event, the genetic disease will eventually be driven out of the gene pool, unless, like sickle cell, it has some survival advantage in an isolated population. Then this population will diverge and possibly form a new species in a few hundred thousand years.
There is nothing in this post that I did not already know or agree with. Obviously, you either don't know how to read or just fail to do so.
The question is increasing complexity.
However, with specific regard to my son, it is not exactly as you say. Cytochrome-C oxidase is actually coded from both nuclear and non-nuclear (mitochondrial) DNA. It is unknown whether his disorder is from the mitochondrial DNA or the nuclear DNA. If it is from the mitochondrial DNA it is actually ONLY based on the maternal side.
Do you really enjoy acting like you're the only person in the world who knows anything? Do you really think that creationists don't understand basic mendellian genetics or natural selection? You probably forgot that mendellian genetics was discovered by a creationist :)
Anyway, if you bothered to read and understand what others are saying, you might have better arguments. Just adding words to previous arguments doesn't in itself make a better argument.