The Invitae Treacher Collins Syndrome test analyzes the TCOF1 gene, which is associated with Treacher Collins syndrome, a condition that is characterized by hypoplasia of the facial bones—particularly the cheek and jaw bones—as well as ear abnormalities and coloboma. Genetic testing of this gene may confirm a diagnosis and help guide treatment and management. Identification of a disease-causing variant can inform recurrence-risk assessment and genetic counseling.
Approximately 70%–93% of individuals who meet diagnostic criteria for Treacher Collins syndrome have an identifiable pathogenic variant in TCOF1.
Treacher Collins syndrome is inherited in an autosomal dominant pattern. Approximately 60% of cases are attributable to de novo pathogenic variants.
TCOF1 mutations are highly penetrant; however, cases of reduced penetrance have been reported. Significant inter- and intrafamilial variability has been observed.
The prevalence of Treacher Collins syndrome is approximately 1 in 10,000–50,000.
This test could be considered for patients who present with midface hypoplasia, absent or small, malformed or rotated ears, coloboma, sparse or absent eyelashes, or conductive hearing loss. Other, less-common features include cleft palate with or without cleft lip and choanal stenosis or atresia.
Invitae is a College of American Pathologists (CAP)-accredited and Clinical Laboratory Improvement Amendments (CLIA)-certified clinical diagnostic laboratory performing full-gene sequencing and deletion/duplication analysis using next-generation sequencing technology (NGS).
Our sequence analysis covers clinically important regions of each gene, including coding exons, +/- 10 base pairs of adjacent intronic sequence, and select noncoding variants. Our assay provides a Q30 quality-adjusted mean coverage depth of 350x (50x minimum, or supplemented with additional analysis). Variants classified as pathogenic or likely pathogenic are confirmed with orthogonal methods, except individual variants that have high quality scores and previously validated in at least ten unrelated samples.
Our analysis detects most intragenic deletions and duplications at single exon resolution. However, in rare situations, single-exon copy number events may not be analyzed due to inherent sequence properties or isolated reduction in data quality. If you are requesting the detection of a specific single-exon copy number variation, please contact Client Services before placing your order.
|Gene||Transcript reference||Sequencing analysis||Deletion/Duplication analysis|