Treacher Collins Syndrome is a rare genetic disorder also named (Treacher Collins-) Franceschetti syndrome and can be caused by variants in TCOF1 or POLR1B, POLR1C and POLR1D
Main clinical features
People with Treacher Collins syndrome (TCS) have generally a distinctive facial appearance since birth with:
• Underdeveloped or absent cheekbones
• The lower jaw is incompletely developed so the jaw appears abnormally small
• Abnormal ears, small ears
• Lower eyelid abnormalities
Potentially they develop hearing and vision problems. The facial anomalies can also affect breathing, swallowing and speaking.
The appearance and severity of the symptoms varies from one person to another, even in the same family. Affected individuals not have always all of the symptoms listed above. Sometimes the symptoms are so mild that the person remains undiagnosed.
Typically, the intelligence and fertility is normal.
Prevalence
The prevalence of Treacher Collins syndrome is estimated at 1/50 000.
About 80-85% TCS cases with typical facial features is caused by TCOF1 variants.
Inheritance
TCS due to TCOF1-Variants is inherited in an autosomal dominant manner. This means that genetically female and male can be affected in the same way and that one variant in one copy of the two TCOF1-copys is sufficient to cause TCS.
Manifestations
The anomalies of head and face can lead to different problems including airways, ophthalmic and dental issues and sleep apneas. Treatment is symptomatic and multidisciplinary.
TCOF1