Introduction

Whole Exome Sequencing

Many undiagnosed disorders are associated with multiple symptoms that are heterogeneous and variable, rendering results of traditional biochemical-based testing ambiguous and difficult to interpret. Follow-on genetic testing for these suspected cases enables confirmation of the diagnosis. Genetic testing of certain genetic disorders may also be appropriate when treatment availability is dependent on a specific gene affected.

When to Consider Whole Exome Sequencing?

The Rainbow Low-Cost Whole Exome Sequencing Test provides physicians with timely ascertainment to determine the genetic etiologies of a variety of genetic disorders.

This test may be suitable for families who do not want to wait for approval to receive an exome sequencing test provided by local hospitals. In Asia, such wait time could exceed one year.

In addition, many low-income families and patients with limited budgets do not have access to complex genomic testing. We offer a low-cost whole exome sequencing test to these patients and families, enabling them to obtain a timely-diagnosis.

Low-Cost Genetic Counseling Included

Also, low-cost genetic counseling provided by an accredited, Chinese - and English-speaking genetic counselor is available. This service is provided by a genetic counselor with multiple years of clinical experience, who is also dedicated to local community services.

When to Consider Whole Genome Sequencing?

For families who have received a negative report with no pathogenic mutation findings using previous multiple gene or whole exome sequencing tests, we offer low-cost whole genome sequencing to detect mutations not detected by whole exome sequencing.

Triple Repeat Analysis

We also offer the following REPEAT EXPANSION tests at low-cost levels that can be ordered. Whole exome sequencing is not suitable for detection of the following triple-repeat-associated disorders.

• FRAGILE X SYNDROME

• HUNTINGTON DISEASE

• KENNEDY DISEASE

• FRIEDREICH ATAXIA

Whole exome sequencing is not designed to detect these repeat expansion variants. The above repeat expansion tests are offered at low cost level to be used with whole exome sequencing tests.

Whole Exome Sequencing

• Examples of Conditions

  • Developmental Delay

  • Speech Delay

  • Intellectual Disability

  • Neurological Disorders including Epilepsy/Seizure

  • Dysmorphic Features

  • Congenital Heart Disease

  • Congenital Eye Disorders

  • Pediatric growth abnormalities such as

    • Tall/Short stature

    • Early Puberty

    • Abnormal Genital Morphology

  • Hypo- or Hyper-Pigmentation

  • Skeletal Abnormalities

  • RASopathy

  • Connective Tissue Disorders such as Ehlers-Danlos syndromes

  • Congenital Hearing Loss

  • Metabolic Disorders (See list below)

Proband vs. Trio sequencing

It has been shown that sequencing both parents in addition to sequencing the child (a trio) increases the yield of a diagnosis, particularly for cases where there were no prior family histories. One reason for the higher diagnostic rate is because of the successful identification of de novo and compound heterozygous mutations via trio sequencing. Rainbow Genomics recommends trio sequencing whenever possible for pediatric patients.

Diagnostic Testing

• Based on whole exome sequencing, this is a diagnostic analysis associated with patient's symptoms

• Whole Exome Sequencing at 200X Depth

• Or, choose Whole Genome Sequencing if previous multi-gene or whole exome sequencing testing failed to identify pathogenic mutations.

• Report pathogenic variants, causative copy-number variants and variants of uncertain clinical significance

• Regular turnaround time is 1.5-2 months