here are two ways that Treacher Collins syndrome develops.
First, Treacher Collins can develop as a new mutation. This means that both parents pass on normal genes to their child. However, sometimes very early in development a change in one of the genes leads to this mutation. At the present, there is no evidence that the mother’s actions or activities during her pregnancy contribute to this condition.
The second way that Treacher Collins syndrome develops is by inheriting it from one of the parents. It should be noted that sometimes one of the parents may have such a mild form of the condition that it goes undetected. It is not until a child is born with the syndrome that it is realized that the mother or father also has the condition.