The Invitae Cohen syndrome test analyzes VPS13B (also known as COH1), a gene associated with Cohen syndrome, a multisystem disorder characterized by developmental delay, intellectual disability, microcephaly, hypotonia and truncal obesity.
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.
Cohen syndrome is a developmental disorder characterized by intellectual disability, microcephaly, hypotonia, joint hypermobility, characteristic facial features, short stature, progressive early onset myopia, progressive retinochoroidal dystrophy, neutropenia and truncal obesity developing in late childhood. Affected individuals are described as having a happy disposition. The features of Cohen syndrome can vary widely between individuals.
Approximately 88% of patients with a strong clinical suspicion of Cohen syndrome have homozygous or compound heterozygous pathogenic variants in VPS13B.
Cohen syndrome is inherited in an autosomal recessive manner.
Cohen syndrome is a highly penetrant condition with variable expressivity.
An exact prevalence of Cohen syndrome is not yet known. It has been diagnosed in fewer than 1,000 people worldwide.
This test could be considered for patients who present with six or more of the following criteria (PMID: 15141358):
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|