It is autosomal dominant heterozygous. A minute number of cases are speculated to be autosomal recessive. Marfan Syndrome is not sex-linked. Mechanism of the Disorder Marfan is caused by mutations of the FBN I involve skipping exons that encode the calcium binding epidermal growth factor. Mutations can vary depending on the specific exons skipped.
Some skips are a premature termination codon in exon four.
One of the mutations affects the synthesis, secretion, and matrix incorporation and deposition of the Fibrillin protein. This creates a dominant negative effect. I is a glycoporotein of the microfibrill. On occasion the microfibrill's formation is disorganized These collagens are a major structural component of connective tissue. Irregularities in the connective tissue are primarily found in the ground substance.