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Joubert Syndrome via the TMEM216 Gene

Summary and Pricing

Test Method

Sequencing and CNV Detection via NextGen Sequencing using PG-Select Capture Probes
Test Code Test Copy GenesTest CPT Code Gene CPT Codes Copy CPT Codes Base Price
TMEM216 81479 81479,81479 $990
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
7847TMEM21681479 81479,81479 $990 Order Options and Pricing

Pricing Comments

Testing run on PG-select capture probes includes CNV analysis for the gene(s) on the panel but does not permit the optional add on of exome-wide CNV analysis. Any of the NGS platforms allow reflex to other clinically relevant genes, up to whole exome or whole genome sequencing depending upon the base platform selected for the initial test.

An additional 25% charge will be applied to STAT orders. STAT orders are prioritized throughout the testing process.

This test is also offered via a custom panel (click here) on our exome or genome backbone which permits the optional add on of exome-wide CNV or genome-wide SV analysis.

Turnaround Time

3 weeks on average for standard orders or 2 weeks on average for STAT orders.

Please note: Once the testing process begins, an Estimated Report Date (ERD) range will be displayed in the portal. This is the most accurate prediction of when your report will be complete and may differ from the average TAT published on our website. About 85% of our tests will be reported within or before the ERD range. We will notify you of significant delays or holds which will impact the ERD. Learn more about turnaround times here.

Targeted Testing

For ordering sequencing of targeted known variants, go to our Targeted Variants page.


Genetic Counselors


  • Fang Xu, PhD, FACMG

Clinical Features and Genetics

Clinical Features

Joubert syndrome (JS) (OMIM 213300) is marked by hypotonia, abnormal ocular movements, neonatal respiratory difficulties, mental retardation, hypoplasia of the cerebellar vermis, and malformation of the brainstem. The brain malformations lead to the "molar tooth sign" on cranial MRI, which is the hallmark clinical feature of JS. Other variable JS features include cystic kidneys, nephronophthisis, retinal dystrophy, ocular coloboma, occipital encephalocele, polydactyly, ataxia, and hepatic fibrosis.


JS is inherited in an autosomal recessive manner. Recently, an Ashkenazi Jewish founder variant was identified in the TMEM216 gene as a new cause of JS (Edvardson et al. Am J Hum Genet 86:93-97, 2010). Additional families from other ethnicities have also been linked to the JBTS2 region, which harbors TMEM216. Other cases of JS have also been linked to variants in the AHI1, CEP290, TMEM67/MKS3, RPGRIP1L, INPP5E, ARL13B, and NPHP1 genes. PreventionGenetics performs tests for all of these genes.

Clinical Sensitivity - Sequencing with CNV PG-Select

This test should be performed first for patients with Ashkenazi Jewish ancestry.

The prevalence of JS is approximately 1 in 100,000. The following are the approximate fractions of patients with variants in the indicated genes for Joubert syndrome: TMEM67/MKS3 10%, AHI1 10%, CC2D2A 10%, CEP290 10%, RPGRIP1L 2%, ARL13B 2%, and NPHP1 2%.

Testing Strategy

This test provides full coverage of all coding exons of the TMEM216 gene, plus ~10 bases of flanking noncoding DNA. We define full coverage as >20X NGS reads or Sanger sequencing.

To support research and because development of this test was funded by the NIH, a completed Clinical Feature Checklist, which is available from our web site, must accompany each test requisition. Checklists are not required for carrier testing.

Indications for Test

Candidates for this test are patients with symptoms consistent with JS and the family members of patients who have known variants. Conclusive connections between clinical features and mutated genes have not yet been made for JS. This test should be performed first for patients with Ashkenazi Jewish ancestry. This test may also be considered for the reproductive partners of individuals who carry pathogenic variants in TMEM216.


Official Gene Symbol OMIM ID
TMEM216 613277
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT


Name Inheritance OMIM ID
Joubert Syndrome 2 AR 608091
Meckel Syndrome 2 AR 603194


  • Edvardson, S., et.al. (2010). PubMed ID: 20036350


Ordering Options

We offer several options when ordering sequencing tests. For more information on these options, see our Ordering Instructions page. To view available options, click on the Order Options button within the test description.

myPrevent - Online Ordering

  • The test can be added to your online orders in the Summary and Pricing section.
  • Once the test has been added log in to myPrevent to fill out an online requisition form.
  • PGnome sequencing panels can be ordered via the myPrevent portal only at this time.

Requisition Form

  • A completed requisition form must accompany all specimens.
  • Billing information along with specimen and shipping instructions are within the requisition form.
  • All testing must be ordered by a qualified healthcare provider.

For Requisition Forms, visit our Forms page

If ordering a Duo or Trio test, the proband and all comparator samples are required to initiate testing. If we do not receive all required samples for the test ordered within 21 days, we will convert the order to the most effective testing strategy with the samples available. Prior authorization and/or billing in place may be impacted by a change in test code.

Specimen Types

Specimen Requirements and Shipping Details

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View Ordering Instructions

1) Select Test Method (Platform)

1) Select Test Type

2) Select Additional Test Options

No Additional Test Options are available for this test.

Note: acceptable specimen types are whole blood and DNA from whole blood only.
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