A collection of over 200 disorders involving genetic mutations of the proteins that make up the bodies connective tissues. They are all known to be carried down from one generation to the next; some are known to be autosomal dominant (only one parent has to carry the gene) and others are autosomal recessive (both parents have to carry the gene). Some HDCTs can change the growth and appearance of certain physical features, sometimes in utero (making it difficult to decipher between what is and is not normal). Most Chiari Specialists now agree that most (some even say all) cases of Chiari Malformation involve some form of a Connective Tissue Disorder.

Some HDCTs Common to Chiarians, include: