TCS is a rare genetic disorder affecting roughly 1 in every 10,000 births.

It is characterised by craniofacial abnormalities. This basically means that certain portions of the skull are underdeveloped, and tends to involve the cheekbones, jaws, mouth, ears, and eyes. The symptoms and physical characteristics can vary greatly in severity, in fact it is possible to have it so slightly that you may not notice. More detail on the typical abnormalities can be found in the Characteristics section.

The first case of Treacher Collins Syndrome was described in 1846, and was given it's name in 1900 when a British ophthalmologist, Dr Treacher Collins gave a definite diagnosis. The gene responsible for this syndrome has now been located and identified. It has been named the "Treacle" gene. You can read the articles about when the Chromosome was identified in 1991 and when the gene was identified in 1996:

03Feb1996	USA: IRVINE - UCI Scientists Isolate Facial Disorder Gene.
10Sep1991	UK: Medical scientists identify chromosome carrying gene for Treacher Collins Syndrome.

A much more detailed description of the genetics and inheritance can be found in the genetics section.