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Aniridia via the PAX6 Gene

Summary and Pricing

Test Method

Exome Sequencing with CNV Detection
Test Code Test Copy GenesTest CPT Code Gene CPT Codes Copy CPT Codes Base Price
8193 PAX6 81479 81479,81479 $890 Order Options and Pricing
Test Code Test Copy Genes Test CPT Code Gene CPT Codes Copy CPT Code Base Price
8193PAX681479 81479,81479 $890 Order Options and Pricing

Pricing Comments

Our favored testing approach is exome based NextGen sequencing with CNV analysis. This will allow cost effective reflexing to PGxome or other exome based tests. However, if full gene Sanger sequencing is desired for STAT turnaround time, insurance, or other reasons, please see link below for Test Code, pricing, and turnaround time information. If the Sanger option is selected, CNV detection may be ordered through Test #600.

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

Click here for costs to reflex to whole PGxome (if original test is on PGxome Sequencing backbone).

Click here for costs to reflex to whole PGnome (if original test is on PGnome Sequencing backbone).

The Sanger Sequencing method for this test is NY State approved.

For Sanger Sequencing click here.

Turnaround Time

18 days on average for standard orders or 13 days 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.

EMAIL CONTACTS

Genetic Counselors

Geneticist

  • Dana Talsness, PhD

Clinical Features and Genetics

Clinical Features

Aniridia (AN) is a rare congenital bilateral panocular disorder defined as iris aplasia or hypoplasia resulting in reduced visual acuity and nystagmus (Nelson et al.1984). It can be isolated or, in rare cases, associated with multiple ocular abnormalities such as cataracts, glaucoma (Mihelec et al. 2008), Peter’s anomaly (Hanson et al. 1994), neurodevelopmental abnormalities (Dansault et al. 2007) and WAGR syndrome(Wilms Tumor-Aniridia-Genitourinary Anomalies-Mental Retardation). The estimated prevalence of AN is about 1 in 40,000 to 100,000 (Hingorani et al. 2008) and is unknown for WAGR syndrome.

Genetics

Approximately two-thirds of AN cases are familial with autosomal dominant inheritance and the remaining one third are sporadic with no previous family history (Nelson et al. 1984; Ton et al. 1991). PAX6 (paired box gene 6; OMIM 607108), which is located on chromosome band 11p13, has been identified as the major candidate gene, if not the only gene, for AN. PAX6 encodes a highly conserved transcription factor that comprises a paired domain, a homeodomain, and a serine/threonine-rich C-terminal domain, and plays an essential role in eye development (Kokotas and Petersen 2010). Mutation frequency is higher in the paired domain as compared to the rest of the gene. Transitions (C>T) at four CpG dinucleotides in exons 8, 9, 10 and 11 are major mutation hotspots and account for ~50% of PAX6 nonsense mutations (Tzoulaki et al. 2005). So far, the vast majority of PAX6 mutations (94%) introduce a premature termination codon (PTC) into the PAX6 coding region and causing haploinsufficiency, which has been the major pathomechanism for AN (Tzoulaki et al. 2005 ; Kokotas and Petersen 2010). PAX6 overexpression is also implicated in severe eye abnormalities (Schedl et al. 1996). Over 330 causative mutations have been identified in PAX6 (Brown et al. 1998). Neonates with sporadic AN carry a risk of developing Wilms' tumor (WT) as part of WAGR syndrome (Nelson et al. 1984), due to the contiguous deletion of WT susceptibility gene (WT1) and PAX6, which are 700kb apart (Nelson et al. 1984 ; Fischbach et al. 2005). A high frequency of chromosomal rearrangements have been associated with both sporadic and familial AN (Crolla and van Heyningen 2002 ; Lim et al. 2012).

Clinical Sensitivity - Sequencing with CNV PGxome

The overall PAX6 mutation detection rate by sequencing in different populations varied from 30-90% (Zhang et al. 2011; Villarroel et al. 2008; Park et al. 2012).

Testing Strategy

This test provides full coverage of all coding exons of the PAX6 gene plus 10 bases of flanking noncoding DNA in all available transcripts along with other non-coding regions in which pathogenic variants have been identified at PreventionGenetics or reported elsewhere. We define full coverage as >20X NGS reads or Sanger sequencing. PGnome panels typically provide slightly increased coverage over the PGxome equivalent. PGnome sequencing panels have the added benefit of additional analysis and reporting of deep intronic regions (where applicable).

Dependent on the sequencing backbone selected for this testing, discounted reflex testing to any other similar backbone-based test is available (i.e., PGxome panel to whole PGxome; PGnome panel to whole PGnome).

Indications for Test

Patients with symptoms suggestive of Aniridia, Coloboma of optic nerve, Foveal hypoplasia and presenile cataract syndrome, Optic nerve hypoplasia and aplasia are candidates.

Gene

Official Gene Symbol OMIM ID
PAX6 607108
Inheritance Abbreviation
Autosomal Dominant AD
Autosomal Recessive AR
X-Linked XL
Mitochondrial MT

Citations

  • Brown A, McKie M, Heyningen V Van, Prosser J. 1998. The human PAX6 mutation database. Nucleic acids research 26: 259–264. PubMed ID: 9399848
  • Crolla JA, Heyningen V van. 2002. Frequent chromosome aberrations revealed by molecular cytogenetic studies in patients with aniridia. The American Journal of Human Genetics 71: 1138–1149. PubMed ID: 12386836
  • Dansault A, David G, Schwartz C, Jaliffa C, Vieira V, Houssaye G de la, Bigot K, Catin F, Tattu L, Chopin C. 2007. Three new PAX6 mutations including one causing an unusual ophthalmic phenotype associated with neurodevelopmental abnormalities. Molecular vision 13: 511. PubMed ID: 17417613
  • Fischbach BV. 2005. WAGR Syndrome: A Clinical Review of 54 Cases. PEDIATRICS 116: 984–988. PubMed ID: 16199712
  • Hanson IM. et al. 1994. Nature Genetics. 6: 168-73. PubMed ID: 8162071
  • Hingorani M, Williamson KA, Moore AT, Heyningen V van. 2009. Detailed ophthalmologic evaluation of 43 individuals with PAX6 mutations. Investigative ophthalmology & visual science 50: 2581–2590. PubMed ID: 19218613
  • Kokotas H, Petersen MB. 2010. Clinical and molecular aspects of aniridia. Clin. Genet. 77: 409–420.
    PubMed ID: 20132240
  • Lim HT, Seo E-J, Kim G-H, Ahn H, Lee H, Shin KH, Lee J-K, Yoo H-W. 2012. Comparison between aniridia with and without PAX6 mutations: clinical and molecular analysis in 14 Korean patients with aniridia. Ophthalmology 119: 1258–1264. PubMed ID: 22361317
  • Mihelec M, St Heaps L, Flaherty M, Billson F, Rudduck C, Tam PPL, Grigg JR, Peters GB, Jamieson RV. 2008. Chromosomal rearrangements and novel genes in disorders of eye development, cataract and glaucoma. Twin Res Hum Genet 11: 412–421. PubMed ID: 18637741
  • Nelson LB, Spaeth GL, Nowinski TS, Margo CE, Jackson L. 1984. Aniridia. A review. Surv Ophthalmol 28: 621–642. PubMed ID: 6330922
  • Park SH, Kim MS, Chae H, Kim Y, Kim M. 2012. Molecular analysis of the PAX6 gene for congenital aniridia in the Korean population: Identification of four novel mutations. Molecular vision 18: 488. PubMed ID: 22393275
  • Schedl A, Ross A, Lee M, Engelkamp D, Rashbass P, Heyningen V van, Hastie ND. 1996. Influence of PAX6 gene dosage on development: overexpression causes severe eye abnormalities. Cell 86: 71–82. PubMed ID: 8689689
  • Ton CC, Hirvonen H, Miwa H, Weil MM, Monaghan P, Jordan T, Heyningen V van, Hastie ND, Meijers-Heijboer H, Drechsler M. 1991. Positional cloning and characterization of a paired box- and homeobox-containing gene from the aniridia region. Cell 67: 1059–1074. PubMed ID: 1684738
  • Tzoulaki I. et al. 2005. Bmc Genetics. 6: 27. PubMed ID: 15918896
  • Villarroel CE, Villanueva-Mendoza C, Orozco L, Alcántara-Ortigoza MA, Jiménez DF, Ordaz JC, González-del Angel A. 2008. Molecular analysis of the PAX6 gene in Mexican patients with congenital aniridia: report of four novel mutations. Molecular vision 14: 1650. PubMed ID: 18776953
  • Zhang X, Wang P, Li S, Xiao X, Guo X, Zhang Q. 2011. Mutation spectrum of PAX6 in Chinese patients with aniridia. Molecular vision 17: 2139. PubMed ID: 21850189

Ordering/Specimens

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


Specimen Types

Specimen Requirements and Shipping Details

PGxome (Exome) Sequencing Panel

PGnome (Genome) Sequencing Panel

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ORDER OPTIONS

View Ordering Instructions

1) Select Test Method (Backbone)


1) Select Test Type


2) Select Additional Test Options

STAT and Prenatal Test Options are not available with Patient Plus.

No Additional Test Options are available for this test.

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