Oculocutaneous Albinism (OCA) Panel
Summary and Pricing
Test MethodExome Sequencing with CNV Detection
|Test Code||Test Copy Genes||Gene CPT Codes Copy CPT Codes|
|10313||AP3D1||81479,81479||Order Options and Pricing|
|Test Code||Test Copy Genes||Panel CPT Code||Gene CPT Codes Copy CPT Code||Base Price|
|10313||Genes x (14)||81479||81404, 81479||$890||Order Options and Pricing|
We are happy to accommodate requests for testing single genes in this panel or a subset of these genes. The price will remain the list price. If desired, free reflex testing to remaining genes on panel is available. Alternatively, a single gene or subset of genes can also be ordered via our PGxome Custom Panel tool.
An additional 25% charge will be applied to STAT orders. STAT orders are prioritized throughout the testing process.
18 days on average for standard orders or 14 days on average for STAT orders.
Once a specimen has started the testing process in our lab, the most accurate prediction of TAT will be displayed in the myPrevent portal as an Estimated Report Date (ERD) range. We calculate the ERD for each specimen as testing progresses; therefore the ERD range may differ from our published average TAT. View more about turnaround times here.
For ordering sequencing of targeted known variants, go to our Targeted Variants page.
Clinical Features and Genetics
Oculocutaneous albinism (OCA) is an inherited disorder caused by deficiency in melanin synthesis that results in hypopigmentation of the skin, eyes, and hair that are present at birth. If the phenotype is mainly restricted to the eyes and the optic system, it is referred to as ocular albinism (OA) (Gargiulo et al. 2011. PubMed ID: 20861488). The reduction or complete absence of melanin pigment in the developing eye leads to foveal hypoplasia and misrouting of the optic nerves in the affected individuals (Oetting and King. 1999. PubMed ID: 10094567). The eye and optic system abnormalities that are common to all types of albinism are nystagmus, photophobia, strabismus, moderate to severe impairment of visual acuity (20/60 to 20/400), reduced iris pigment with iris translucency, reduced retinal pigment with visualization of the choroidal blood vessels on ophthalmoscopic examination, refractive errors and altered visual evoked potentials (VEP).
The degree of skin and hair hypopigmentation varies with the type of OCA, but the ocular phenotype does not change (Grønskov et al. 2009. PubMed ID: 19060277). To date, four types of non-syndromic OCA (type I-IV, based on gene involved) have been described, and their prevalence varies among different populations with approximate overall incidence is one in 17,000 people have one of the types of albinism (Grønskov et al. 2009. PubMed ID: 19060277).
OCA is genetically heterogeneous and exhibits autosomal recessive (AR), and X-linked (XL) inheritance. So far, 13 genes have been implicated in different forms of OCA. All kinds of causative mutations (missense, nonsense, splicing, small as well as gross deletions and duplications, complex genomic rearrangements) have been reported in OCA (Human Gene Mutation Database). The major autosomal recessive (ar) nonsyndromic forms OCA I and II are caused by genetic variations in TYR and OCA2 genes, respectively. The other nonsyndromic ar forms OCA III and IV involve TYRP1 and SLC45A2 genes, respectively (Simeonov et al. 2013).
TYR encoded Tyrosinase and TYRP1 encoded tyrosinase-related protein catalyze the initial steps in melanin production. The P-protein encoded by OCA2 and the solute carrier 45 subunit A2 encoded by SLC45A2 are transporters localized in the melanosome membrane (Preising et al. 2011). Mutations in GPR143 are associated with X-linked ocular albinism. GPR143 encoded protein is a G protein-coupled receptor (GPCR) and is involved in intracellular signal transduction system and in the regulation of melanosome biogenesis and growth (Schiaffino and Tacchetti 2005; Mayeur et al. 2006). Recently, mutations in two new genes, LRMDA and SLC24A5, were also associated with non-syndromic arOCA (Grønskov et al. 2013; Wei et al. 2013).
Clinical findings of hypopigmentation of the skin and hair, in addition to the characteristic ocular symptoms are present in many syndromic disorders. Examples are Hermansky-Pudlak syndrome (HPS) (Schreyer-Shafir et al. 2006), Chediak Higashi Syndrome (CHS) (Kaya et al. 2011), Griscelli syndrome(GS) (Ménasché et al. 2000; Pastural et al. 1997) and Waardenburg syndrome(WS) (Morell et al. 1997). The causative mutations in HSP6, LYST, MYO5A, AP3D1 and RAB27A are associated with the syndromic forms of arOCA. MITF and MC1R have been reported to have a digenic inheritance with TYR and OCA2 (Morell et al. 1997; Preising et al. 2011).
See individual gene test descriptions for information on molecular biology of gene products.
Clinical Sensitivity - Sequencing with CNV PGxome
A molecular screening of the TYR, OCA2, TYRP1, SLC45A2 genes in 121 unrelated non-Hispanic/Latino Caucasian OCA patients identified mutations in TYR (69%), OCA2 (18%), SLC45A2 (6%), and no apparent pathological mutations in 7% of patients (Hutton and Spritz 2008). These results indicate the heterogeneity of this disorder. Another study in Chinese OCA patients identified mutations in TYR (36%), OCA2 (25%), TYRP1(2%), SLC45A2 (11%) and GPR143 (6%) (Morice-Picard et al. 2014). Clinical sensitivity for other genes is currently unknown due to limited cases.
Gross deletions and duplications have been reported in TYR, OCA2, SLC45A2 and GPR143 genes. However, gross deletions in HPS6, LYST and RAB27A have not been associated with OCA (Human Gene Mutation Database).
This test is performed using Next-Gen sequencing with additional Sanger sequencing as necessary.
This panel typically provides 99.4% coverage of all coding exons of the genes 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 coverage as ≥20X NGS reads or Sanger sequencing.
Since this test is performed using exome capture probes, a reflex to any of our exome based tests is available (PGxome, PGxome Custom Panels).
This panel does not include the common OCA2 deletion common in African countries (see test #3738).
Indications for Test
All patients with symptoms suggestive of Oculocutaneous albinism are candidates.
All patients with symptoms suggestive of Oculocutaneous albinism are candidates.
|Official Gene Symbol||OMIM ID|
- Gargiulo A, Testa F, Rossi S, Iorio V Di, Fecarotta S, Berardinis T de, Iovine A, Magli A, Signorini S, Fazzi E. 2011. Molecular and clinical characterization of albinism in a large cohort of Italian patients. Investigative Ophthalmology & Visual Science 52: 1281–1289. PubMed ID: 20861488
- Grønskov K, Dooley CM, Østergaard E, Kelsh RN, Hansen L, Levesque MP, Vilhelmsen K, Møllgård K, Stemple DL, Rosenberg T. 2013. Mutations in C10orf11, a Melanocyte-Differentiation Gene, Cause Autosomal-Recessive Albinism. The American Journal of Human Genetics 92: 415–421. PubMed ID: 23395477
- Human Gene Mutation Database (Bio-base).
- Hutton SM, Spritz RA. 2008. Comprehensive Analysis of Oculocutaneous Albinism among Non-Hispanic Caucasians Shows that OCA1 Is the Most Prevalent OCA Type. Journal of Investigative Dermatology 128: 2442–2450. PubMed ID: 18463683
- Kaya Z, Ehl S, Albayrak M, Maul-Pavicic A, Schwarz K, Kocak U, Ergun MA, Gursel T. 2011. A novel single point mutation of the LYST gene in two siblings with different phenotypic features of Chediak Higashi syndrome. Pediatr Blood Cancer 56: 1136–1139. PubMed ID: 21488161
- Lewis RA. 2012. Oculocutaneous Albinism Type 2. In: Pagon RA, Adam MP, Bird TD, Dolan CR, Fong C-T, and Stephens K, editors. GeneReviews™, Seattle (WA): University of Washington, Seattle. PubMed ID: 20301410
- Lewis RA. 2013. Oculocutaneous Albinism Type 1. In: Pagon RA, Adam MP, Bird TD, Dolan CR, Fong C-T, Smith RJ, and Stephens K, editors. GeneReviews™, Seattle (WA): University of Washington, Seattle. PubMed ID: 20301345
- Mayeur H, Roche O, Vêtu C, Jaliffa C, Marchant D, Dollfus H, Bonneau D, Munier FL, Schorderet DF, Levin AV, others. 2006. Eight previously unidentified mutations found in the OA1 ocular albinism gene. BMC medical genetics 7: 41. PubMed ID: 16646960
- Ménasché G, Pastural E, Feldmann J, Certain S, Ersoy F, Dupuis S, Wulffraat N, Bianchi D, Fischer A, Deist F Le, Saint Basile G de. 2000. Mutations in RAB27A cause Griscelli syndrome associated with haemophagocytic syndrome. Nat. Genet. 25: 173–176. PubMed ID: 10835631
- Morell R, Spritz RA, Ho L, Pierpont J, Guo W, Friedman TB, Asher JH. 1997. Apparent digenic inheritance of Waardenburg syndrome type 2 (WS2) and autosomal recessive ocular albinism (AROA). Human molecular genetics 6: 659–664. PubMed ID: 9158138
- Morice-Picard F, Lasseaux E, François S, Simon D, Rooryck C, Bieth E, Colin E, Bonneau D, Journel H, Walraedt S, Leroy BP, Meire F, Lacombe D, Arveiler B. 2014. SLC24A5 Mutations Are Associated with Non-Syndromic Oculocutaneous Albinism. J Invest Dermatol 134: 568–571. PubMed ID: 23985994
- Oetting WS, King RA. 1999. Molecular basis of albinism: mutations and polymorphisms of pigmentation genes associated with albinism. Hum. Mutat. 13: 99–115. PubMed ID: 10094567
- Pastural E, Barrat FJ, Dufourcq-Lagelouse R, Certain S, Sanal O, Jabado N, Seger R, Griscelli C, Fischer A, Saint Basile G de. 1997. Griscelli disease maps to chromosome 15q21 and is associated with mutations in the myosin-Va gene. Nat. Genet. 16: 289–292. PubMed ID: 9207796
- Preising MN, Forster H, Gonser M, Lorenz B. 2011. Screening of TYR, OCA2, GPR143, and MC1R in patients with congenital nystagmus, macular hypoplasia, and fundus hypopigmentation indicating albinism. Molecular vision 17: 939. PubMed ID: 21541274
- Schiaffino MV, Tacchetti C. 2005. The ocular albinism type 1 (OA1) protein and the evidence for an intracellular signal transduction system involved in melanosome biogenesis: OA1 and signal transduction at internal membranes. Pigment Cell Research 18: 227–233. PubMed ID: 16029416
- Schreyer-Shafir N, Huizing M, Anikster Y, Nusinker Z, Bejarano-Achache I, Maftzir G, Resnik L, Helip-Wooley A, Westbroek W, Gradstein L, Rosenmann A, Blumenfeld A. 2006. A new genetic isolate with a unique phenotype of syndromic oculocutaneous albinism: clinical, molecular, and cellular characteristics. Hum. Mutat. 27: 1158. PubMed ID: 17041891
- Simeonov DR, Wang X, Wang C, Sergeev Y, Dolinska M, Bower M, Fischer R, Winer D, Dubrovsky G, Balog JZ, Huizing M, Hart R, Zein WM, Gahl WA, Brooks BP, Adams DR. 2013. DNA Variations in Oculocutaneous Albinism: An Updated Mutation List and Current Outstanding Issues in Molecular Diagnostics. Human Mutation 34: 827–835. PubMed ID: 23504663
- Wei A-H, Zang D-J, Zhang Z, Liu X-Z, He X, Yang L, Wang Y, Zhou Z-Y, Zhang M-R, Dai L-L, Yang X-M, Li W. 2013. Exome sequencing identifies SLC24A5 as a candidate gene for nonsyndromic oculocutaneous albinism. J. Invest. Dermatol. 133: 1834–1840. PubMed ID: 23364476
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.
- 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.