Name of the Procedure:

Molecular Cytogenetics; DNA Probe, Each (e.g., FISH)

Summary

Molecular cytogenetics using DNA probes, such as Fluorescence In Situ Hybridization (FISH), is a diagnostic technique that helps detect specific DNA sequences within the cells. It allows for the visualization of genetic material and identification of chromosomal abnormalities, which can be crucial in diagnosing and monitoring various genetic disorders and cancers.

Purpose

This procedure is used to diagnose genetic conditions and chromosomal abnormalities, such as Down syndrome, leukemia, and other cancers. The goal is to provide precise genetic information that can guide treatment decisions and management of the condition.

Indications

• Presence of symptoms suggestive of genetic disorders.
• Suspicion or diagnosis of cancers like leukemia.
• Prenatal screening for chromosomal abnormalities.
• Family history of genetic conditions.
• Unexplained developmental delays or congenital anomalies.

Preparation

• No specific fasting or medication adjustments required.
• Patients may need to provide a blood sample, bone marrow sample, or tissue biopsy.
• Prenatal FISH may require amniotic fluid or chorionic villus samples.
• Pre-procedure genetic counseling is recommended.

Procedure Description

1. Obtain the sample (blood, bone marrow, amniotic fluid, etc.).
2. Fix and prepare the sample for analysis.
3. Apply fluorescently labeled DNA probes to the sample.
4. Incubate the sample to allow the probes to hybridize with targeted DNA sequences.
5. Use a fluorescence microscope to visualize hybridized probes and capture images.
6. Analyze the images to detect the presence or absence of specific genetic sequences or abnormalities.

Tools include fluorescently labeled DNA probes and a fluorescence microscope. No anesthesia or sedation is required for the analysis, though sample collection might need local anesthesia.

Duration

The analysis typically takes several hours to a couple of days, depending on the complexity and type of sample.

Setting

Performed in specialized laboratories equipped to handle sophisticated molecular analyses.

Personnel

• Clinical geneticists
• Laboratory technicians specialized in molecular cytogenetics
• Pathologists

Risks and Complications

• Minimal to no risks from the test itself.
• Sample collection might pose minimal risks like bleeding or infection, especially if involving bone marrow or amniotic fluid.

Benefits

• Accurate diagnosis of genetic conditions and cancers.
• Information that guides treatment and management.
• Results available within a few days to a week.

Recovery

• No specific recovery needed from the analysis.
• Minor discomfort possible at the sample collection site.
• Follow specific care instructions if undergoing invasive sample collection.

Alternatives

• Conventional cytogenetic analysis (karyotyping)
• Comparative genomic hybridization (CGH)
• Polymerase chain reaction (PCR)

Pros and cons vary; for example, FISH can be faster and more specific but may not detect all types of genetic changes.

Patient Experience

• Slight discomfort or anxiety related to sample collection.
• Generally painless and non-invasive analysis.
• Any pain from sample collection is managed with standard pain relief measures.
• Patients can resume normal activities immediately after sample collection, barring any special instructions from their doctor.