Joubert Syndrome: Deletion/Duplication Panel
Condition Description
Joubert syndrome (JS) is an autosomal recessive multisystem disease
characterized by cerebellar vermis hypoplasia with prominent superior
cerebellar peduncles (resulting in the 'molar tooth sign', or MTS, on
axial MRI), intellectual disability, hypotonia, irregular breathing
pattern, and eye movement abnormalities. Some individuals with JS have
retinal dystrophy and/or progressive renal failure characterized as
nephronophthisis. The disorder in such patients is referred to as
cerebellooculorenal syndrome, or CORS. Individuals with a mild form of
JS have been shown to have a homozygous deletion of the NPHP1 gene
identical, by mapping, to that in subjects with nephronophthisis alone.
Please note, the CEP164 gene is not included in the NGS panel at this time due to presence of at least one pseudogene. For clinicians that would like CEP164 analysis in the event that all other genes test negative, we request that you contact EGL directly. Please note, the TMEM138 and TMEM231 genes are not included on the NGS panel at this time as these genes are only partially annotated in hg19. TMEM138 and TMEM231 will be re-evaluated with the release of hg20.
References:
References:
- Daiger et al. (1998) Invest Ophthalmol Vis Sci 39:S295.
- OMIM
- GeneReviews
Genes (18)
Your search may have returned a result for a gene alias. Click here for a full list of genes and their aliases.
Indications
This test is indicated for:
- Confirmation of a clinical diagnosis of Joubert syndrome.
- Carrier testing in adults with a family history of Joubert syndrome.
Methodology
Deletion/Duplication Analysis: DNA
isolated from peripheral
blood is hybridized to a gene-targeted CGH array to detect deletions and
duplications. The targeted CGH array has overlapping probes that cover
the entire genomic region.
Please note that a "backbone" of probes across the entire genome are included on the array for analytical and quality control purposes. Rarely, off-target copy number variants causative of disease may be identified that may or may not be related to the patient's phenotype. Only known pathogenic off-target copy number variants will be reported. Off-target copy number variants of unknown clinical significance will not be reported.
Please note that a "backbone" of probes across the entire genome are included on the array for analytical and quality control purposes. Rarely, off-target copy number variants causative of disease may be identified that may or may not be related to the patient's phenotype. Only known pathogenic off-target copy number variants will be reported. Off-target copy number variants of unknown clinical significance will not be reported.
Detection
Deletion/Duplication: Detection is limited to duplications
and deletions. The CGH array will not detect point or intronic
pathogenic variants. Results of molecular analysis must be interpreted
in the context of the patient's clinical and/or biochemical phenotype.
Specimen Requirements
When sample fails to meet the acceptable criteria, please call 470.378.2200 and ask to speak with a laboratory genetic counselor (eglgc@egl-eurofins.com).
Submit only 1 of the following specimen types
Type: Whole Blood
Specimen Requirements:
In EDTA (purple top) tube:Infants (<2 years): 2-3 ml
Children (>2 years): 3-5 ml
Older Children & Adults: 5-10 ml.
Specimen Collection and Shipping: Ship sample at room temperature with overnight delivery.
Type: Isolated DNA
Specimen Requirements:
In microtainer: 10 ugIsolation using the QiagenTM Puregene kit for DNA extraction is recommended.
Specimen Collection and Shipping: Refrigerate until time of shipment in 100 ng/ul of TE buffer. Ship sample at room temperature with overnight delivery.
Special Instructions
Please include fundus photographs, electroretinogram (ERG) findings,
visual field findings, and visual acuity, if available, for expert
review and clinical correlation with test results.
Related Tests
- Joubert Syndrome: Sequencing Panel
- Eye Disorders: Comprehensive Sequencing Panel
- Eye Disorders: Deletion/Duplication Panel