Name of the Procedure

Hearing Loss Duplication/Deletion Analysis Panel (including STRC, DFNB1 deletions involving GJB2 and GJB6 genes)

Summary

This procedure involves a genetic test to identify specific duplications or deletions in genes associated with hearing loss, such as nonsyndromic hearing loss, Usher syndrome, and Pendred syndrome. It specifically includes copy number analyses for STRC and DFNB1 deletions in the GJB2 and GJB6 genes.

Purpose

This genetic test is used to diagnose the cause of hearing loss and to identify specific genetic mutations associated with the condition. The goal is to provide accurate diagnosis, enable personalized treatment plans, and facilitate genetic counseling for affected individuals and their families.

Indications

• Individuals with a family history of hearing loss.
• Patients showing symptoms of hearing loss, especially of a genetic nature.
• Those diagnosed with syndromes like Usher syndrome or Pendred syndrome.
• Newborns or infants with failed hearing screening tests.
• Patients with nonsyndromic hearing loss.

Preparation

• No special preparation like fasting is generally required.
• A simple blood sample or cheek swab may be collected.
• Patients may be asked to provide family history and previous medical records related to hearing.

Procedure Description

1. Collection of a blood sample or cheek swab from the patient.
2. DNA extraction from the sample is performed in the laboratory.
3. Molecular techniques such as Multiplex Ligation-dependent Probe Amplification (MLPA) or array Comparative Genomic Hybridization (aCGH) are used to detect duplications or deletions in the targeted genes.
4. Analysis focuses on identifying copy number variations in STRC, and deletions in the GJB2 and GJB6 genes related to DFNB1.

Duration

The sample collection takes about 15-30 minutes. Laboratory analysis can take several days to a few weeks.

Setting

The sample is collected in a clinical setting, such as a healthcare provider's office or a diagnostic laboratory. The actual genetic analysis is performed in a specialized genetic testing laboratory.

Personnel

• Genetic counselors
• Medical laboratory technologists
• Geneticists
• Healthcare providers who interpret the results

Risks and Complications

• The procedure involves minimal risk, mainly related to sample collection (e.g., slight discomfort or bruising at the blood collection site).
• Possible psychological impact of genetic testing results, especially if they indicate a serious or inherited condition.

Benefits

• Accurate identification of genetic causes of hearing loss.
• Tailored treatments and interventions based on the specific genetic findings.
• Informed planning and counseling for families affected by genetic hearing loss.

Recovery

• No physical recovery needed from the sample collection.
• Patients might need support and guidance to understand the results and implications of the genetic test.

Alternatives

• Traditional audiological assessments and physical examinations.
• Other types of genetic testing, such as whole-exome sequencing, which may provide broader results but at a higher cost and complexity.
• Non-genetic approaches like hearing aids or cochlear implants, depending on the condition’s nature.

Patient Experience

• The sample collection (blood draw or cheek swab) is usually quick and minimally invasive.
• Anxiety may be experienced while waiting for the results or upon receiving genetic information.
• Genetic counseling is offered to help patients and their families understand the results and implications for ongoing management and family planning.