Genetics of Marfan Syndrome

[Navin]

I understand that Marfan Syndrome is caused due to one's genetic traits.

I have reason to believe that Marfan Syndrome occurs when there is an abnormal gene on chromosome 15.

However I want to know more about this, how the mutation occurs, and especially if this trait is dominant or something else.

Thanks for your help!

[xand_3r]

The Marfan sindrome is caused by an autosomal dominant allele. The location of the defective gene seems to be the 15th chromosome. Being a dominant allele, it means that the child might be affected only if one of the parents has the disease (meaning that it has the gene). If one of the parents is monozygous for the defective gene, the probability for the descendants to inherit the trait is 100%. If the parent is heterozygous, then the chances are 50%. If both parents are heterozygous, the chances are 75%. Marfan sindrome is a disease of the connective tissue. The most important complications are eye problems (the crystalin is displaced) and heart problems, which may lead to heart failure and eventually death.

[Navin]

Ok, thanks for your help. Now I can conclude that if at least one parent is heterozygous for that gene, there is a possibility of the offspring having Marfan Syndrome.

[weesper]

The gene involved is called fibrillin