Introduction

Rainbow Retinal Dystrophy Genetic Test – Simple and Comprehensive

Diagnosing retinal dystrophy based on symptoms alone can be difficult, as patients often present with a wide range of vision problems.

This genetic test helps confirm the diagnosis by identifying mutations linked to many inherited retinal diseases — including retinitis pigmentosa, cone-rod dystrophy, and Leber congenital amaurosis (LCA).

• If a mutation is found in the RPE65 gene, the result may support the use of gene therapy in patients with Leber’s congenital amaurosis.

Patient Information

Why Do Genetic Testing for Retinitis Pigmentosa (RP)?

Genetic testing looks at your DNA to find out which gene changes (mutations) might be causing the condition. Here’s how that can help:

1. Confirm the Diagnosis

Sometimes, symptoms of RP look similar to other eye problems. Genetic testing helps confirm that it is truly RP, and even what type of RP it is, by finding the exact gene that’s affected.

2. Understand How the Condition Will Progress

Different gene mutations can cause different patterns of vision loss. Some types progress slowly, while others affect vision more quickly. Knowing which gene is involved helps doctors give you a better idea of what to expect in the future.

3. Access to New Treatments and Clinical Trials

Some gene-related forms of RP may be eligible for gene therapy or clinical trials. For example, if your RP is caused by changes in the RPE65 gene, there is an FDA-approved gene therapy that can slow or improve vision loss. Without knowing the gene, you wouldn’t know if you qualify.

4. Find Out If Other Family Members Are at Risk

RP is usually inherited. Genetic testing can tell if the condition is passed down from parents and what the chances are that other family members, like your children or siblings, might have it or be carriers.

Duo Test Options

A. Whole genome sequencing (WGS):

WGS reads the entire DNA, every letter in the genetic code, including over 20,000 genes. WGS can offer more answers, especially when the cause of disease is not clear, because it can detect rare mutations or newly discovered genes that other tests might miss.

This test determines:

• Single nucleotide changes (small changes in a single DNA letter)

• Insertions and deletions (indels)

• Exon-level and multi-gene copy number changes (larger missing or duplicated segments of DNA)

• Analysis of over 1,100 genes known to affect retinal structure and function.

B. 330-Gene Test - A Lower Cost Option:

Many known causes of retinitis pigmentosa and inherited retinal diseases are associated with around 300 genes. Our 330-gene panel focuses on the most relevant genes.

• This test is more affordable than WGS, making it an ideal first-line option for many patients.

Testing Process

• These tests are processed at U.S. CLIA-certified and CAP-accredited or Hong Kong ISO-certified clinical laboratories.

• Clinical report is issued by a board-certified medical director.

• Patient readings and genetic counselor summary are included.

For Physicians

Test Descriptions

This test determines the genetic etiologies (genetic causes) associated with a wide range of retinal disorders, including retinitis pigmentosa, cone-rod dystrophy and Leber congenital amaurosis.

Extensive analysis of genetic variants associated with the RPE65 gene may provide evidence for considerations of human gene therapy for RPE65-associated Leber’s congenital amaurosis on visual function.

• Using clinical whole genome sequencing, with analysis of over 20,000 genes coupled with review of disorder-specific genes, this test overcomes the low-diagnostic yield limitation of gene-panel and array-based testing.

• Whole-Genome Analysis - Multiple retinal disorders and their associated pathogenic genetic variants will be reviewed.

  • Over 1100 genes are known to be associated with abnormal retinal morphology. Physicians may choose to use genome sequencing, which analyzes over 20,000 genes, as the first line test to quickly determine the causative gene mutation associated with eye disorder symptoms.

  • Up-to-the-minute, newly-reported genes are automatically included for analysis.

• 330-Gene "Challenging Mutation" Sequencing determines copy number variants (CNVs) and the following "hard-to-detect" mutations:

  • RPGR gene exon 15 (ORF15)

  • CACNA2D4 gene AJ, exon 31-38, exon 35 deletions

  • CLN3 gene 1Kb deletion

  • MAK gene Alu insertion

  • TRPM1 gene AJ, exons 227 duplications and deletions

  • Copy number, duplication, insertion, deletion and single-nucleotide variant analysis included

Major Eye Disorders Tested

• The following specific retinal disorders are tested using both 330-gene and whole genome sequencing

• An additional 1000 disorders (not listed) associated with abnormal retinal morphology are also tested using whole genome sequencing

  • Retinitis pigmentosa (RP)

  • Cone-Rod Dystrophy (CRD)

  • Leber congenital amaurosis (LCA)

  • Congenital non-progressive cone-rod synaptic disorder (CRSD)

  • Achromatopsia

  • Bietti crystalline corneoretinal dystrophy (BCD)

  • Bradyopsia

  • Chediak-Higashi syndrome

  • Choroideremia

  • Congenital nystagmus type 1

  • Congenital stationary night blindness (CSNB)

  • Early and Late-onset Retinal degeneration

  • Ectopia lentis

  • Enhanced S-cone syndrome

  • Familial exudative vitreoretinopathy (FEVR)

  • Fundus albipunctatus (FA)

  • Gyrate atrophy of choroid and retina

  • Isolated microphthalmia

  • Juvenile retinoschisis

  • Microcornea, myopic chorioretinal atrophy, and telecanthus (MMCAT)

  • Microcephaly with chorioretinopathy

  • Microphthalmia, anophthalmia, coloboma (MAC) spectrum

  • Myopia with cataract and vitreoretinal degeneration

  • Neovascular inflammatory vitreoretinopathy (ADNIV)

  • Oculocutaneous albinism

  • Optic atrophy

  • Persistent hyperplastic primary vitreous (PHPVAR)

  • Snowflake vitreoretinal degeneration

  • Stargardt disease

  • Sveinsson chorioretinal atrophy (SCRA)

  • Vitelliform macular dystrophy (VMD1) and autosomal recessive bestrinopathy

Whole Genome

&

Specific Gene Analysis

• Whole genome sequencing test analyze 20,000 genes to determine pathogenic mutations associated with retinal dystrophy, and additional eye disorders, including abnormal retinal morphology.

  • Reporting of gene mutations associated with myopia (near-sightedness) and genetic disorders that can cause myopia can be ordered, at no additional cost. 336 genes associated with these conditions will be analyzed.

• 330-Gene "Challenging Mutation" Sequencing determines difficult-to-detect genetic variants in these genes known to be associated with various retinal dystrophy conditions

• Both tests provide extensive analysis of RPE65 gene. Positive mutation findings in the RPE65 gene may support human gene therapy for RPE65-associated Leber’s congenital amaurosis

Incidental Findings (Health Screening Report) From Your Genome Analysis

• If patients would like to understand their risk of developing a genetic disorders such as hereditary cancers, cardiovascular disorders, familial hypercholesterolemia, hearing, bone and neurological diseases, etc., incidental finding and health screening reports can be ordered with the whole genome sequencing test, at no additional cost to the patients.

• Because we need to screen over 20,000 genes, this health screening report can only be obtained from the whole genome sequencing test data.

• Our Master's degree-holding (Australia) genetic counselor can provide patient genetic counseling regarding any incidental findings. An additional nominal fee will be charged by the counselor.

Test Technical Descriptions

• Both 330-gene sequencing and whole genome sequencing testing are processed at U.S. CLIA-certified and CAP-accredited, high-complexity clinical testing laboratories

• To assure the highest reporting accuracy, Rainbow's Triple Clinical Interpretation(TM) Analysis will be performed

  • Data analysis is performed using US, UK and Israeli bioinformatic platforms

  • Analysis and clinical interpretation are performed by U.S. board-certified clinical geneticists

  • Mutations are further verified by using artificial intelligence and proprietary algorithms

• Clinical reports are issued by board-certified medical directors (MD. & Ph.D.) and clinical geneticists

• Optional English and Chinese language genetic counseling will be provided by U.S. and Australia board-eligible genetic counselors with multiple years of clinical experience

• Written genetic counselor summary is included in the report

Is This Test Right For You?

• If you have eye disorder symptoms and would like to determine if your condition is caused by a gene mutation, you may want to discuss with your physician about receiving this genetic test.

• If you already have a diagnosis of retinitis pigmentosa, and would like to confirm if you carry a mutation in the RPE65 gene, so that you may be able to receive gene therapy, these tests maybe right for you. For more information, please discuss with your physician.

We provide free referrals to physicians with substantial clinical genetic experience for pre- and post-test consultation.