Clinical Guidance

TCOF1

• Individuals with TCOF1 duplications tend to have a milder presentation than individuals with other TCOF1 pathogenic variants .

• The most common 5-bp deletion in exon 24 has been reported to have a higher severity than other exon 24 pathogenic variants .

• Individuals with pathogenic variants in exon 15 have a significantly lower frequency of microtia, conductive deafness, and atresia of the external ear canal .

Source: GeneReviews — "Treacher Collins Syndrome"

Penetrance

While the penetrance of pathogenic variants associated with TCS is high, reduced penetrance in TCOF1 and POLR1D has also been reported.

Source: GeneReviews — "Treacher Collins Syndrome"

Diagnostic Criteria

No consensus clinical diagnostic criteria for Treacher Collins syndrome (TCS) have been published.

Suggestive Findings

TCS should be suspected in probands with the following craniofacial features, conductive hearing loss, and radiographic features.

Craniofacial features

Source: GeneReviews — "Treacher Collins Syndrome"

Differential Diagnosis

Table 3a. Genes of Interest in the Differential Diagnosis of Treacher Collins Syndrome

Management Guidelines

No clinical practice guidelines for Treacher Collins syndrome (TCS) have been published. In the absence of published guidelines, the following recommendations are based on the authors' personal experience managing individuals with this disorder. Evaluations Following Initial Diagnosis To establish the extent of disease and needs in an individual diagnosed with TCS, the evaluations summarized (if not performed as part of the evaluation that led to the diagnosis) are recommended. Table 4. Treacher Collins Syndrome: Recommended Evaluations Following Initial Diagnosis

Source: GeneReviews — "Treacher Collins Syndrome"

Therapies Under Investigation

Search ClinicalTrials.gov in the US and EU Clinical Trials Register in Europe for information on clinical studies for a wide range of diseases and conditions.

Source: GeneReviews — "Treacher Collins Syndrome"

Surveillance Guidelines

To monitor existing manifestations, the individual's response to supportive care, and the emergence of new manifestations, the evaluations summarized in are recommended. Table 5. Recommended Surveillance for Individuals with Treacher Collins Syndrome

Source: GeneReviews — "Treacher Collins Syndrome"