This test analyzes the OFD1 gene, which is the only known gene that is associated with oral-facial-digital syndrome type I (OFD1). OFD1 is an X-linked dominant disorder with lethality in males; it is associated with dysfunction of the primary cilia.
Genetic testing can provide an accurate diagnosis, which can impact an individual’s medical management, help predict disease progression and outcome, and indicate the recurrence risk.
OFD1 is a member of a class of disorders called ciliopathies. Ciliopathies are caused by pathogenic variants in genes that affect the function of cilia— the hair-like structures on the surface of cells. Ciliopathies share many overlapping symptoms, often making it difficult to distinguish between them based on clinical presentation alone.
The Invitae Sensory Ciliopathies Panel has been designed to provide a broad genetic analysis of this class of disorders and may be considered as an alternative to testing for a specific disorder. Depending on the individual’s clinical and family history, this broader panel may be appropriate. It can be ordered at no additional charge.
Oral-facial-digital syndrome type I (OFD1)
Oral-facial-digital syndrome type I (OFD1) is an X-linked dominant developmental disorder that primarily affects the mouth, facial features, and fingers and toes. Symptoms associated with the brain and kidneys may also occur. Oral symptoms include lobed tongue, benign tumors (hamartomas and lipidomas) of the tongue, cleft palate, and oligodontia. Facial features include telecanthus, cleft lip, micrognathia, and hypoplasia of the alae nasi. Digital symptoms include brachydactyly, syndactyly, clinodactyly, and polydactyly. Additional symptoms associated with OFD1 are brain malformations (agenesis of the corpus callosum, cerebellar agenesis, and Dandy-Walker malformation) and the development of cysts in the brain and kidneys. Mild intellectual disability is not uncommon.
Approximately 85% of individuals with oral-facial-digital syndrome type 1 have an identifiable pathogenic variant in the OFD1 gene.
OFD1 is inherited in an X-linked dominant pattern with lethality in males.
OFD1 is a highly penetrant condition with variable expression. OFD1 is lethal in males; nearly all affected individuals are female. The majority of individuals are diagnosed at birth with classic abnormalities noted in the mouth, face and digits; however, some adult females have been reported with absent clinical features until the clinical diagnosis of polycystic kidney disease in adulthood.
Approximately 75% of OFD1 cases are reported with no family history of the disorder.
The prevalence estimates of OFD1 range from 1:250,000 to 1:50,000.
Oral-facial-digital syndrome testing is indicated for any individual who has clinical features that are consistent with OFD1 or a first-degree relative with OFD1.
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|