The Invitae Duane-Radial Ray Syndrome Test analyzes SALL4, a gene that is associated with Duane-Radial Ray syndrome (DRRS), a multisystemic disorder that is characterized by upper-limb, renal, and ocular anomalies. 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.
Duane-Radial Ray syndrome (DRRS) is a disorder that affects the development of upper limbs and causes ocular and, in some cases, renal anomalies. DRRS is characterized by uni- or bilateral Duane anomaly and radial ray malformations and may include other skeletal abnormalities, such as triphalangeal thumbs or preaxial polydactyly. Some individuals with DRRS have genitourinary abnormalities, sensorineural deafness, and gastrointestinal anomalies. Congenital heart defects have also been reported.
Approximately 90%–95% of individuals who meet diagnostic criteria for a SALL4-related disorder have an identifiable pathogenic variant in SALL4.
Duane-Radial Ray syndrome is inherited in an autosomal dominant pattern. Between 40% and 50% of cases are attributable to de novo pathogenic variants.
SALL4 mutations are 95% penetrant and demonstrate variable expressivity.
The prevalence is unknown.
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|