81244 FMR1 (fragile X mental retardation 1) (eg, fragile X mental retardation) gene analysis; characterization of alleles (eg, expanded size and promoter methylation status)

Name of the Procedure:

FMR1 (Fragile X Mental Retardation 1) Gene Analysis; Characterization of Alleles (e.g., Expanded Size and Promoter Methylation Status)

Summary

This procedure involves a genetic test designed to analyze the FMR1 gene for abnormalities, such as expanded trinucleotide repeats and methylation status, which are indicative of fragile X syndrome, a genetic disorder that causes intellectual disability.

Purpose

The primary purpose of the FMR1 gene analysis is to diagnose fragile X syndrome, which can lead to developmental delays, learning disabilities, and cognitive impairment. The goal is to identify mutations that cause fragile X syndrome to provide a definitive diagnosis and guide appropriate clinical management and genetic counseling.

Indications

• Individuals with unexplained intellectual disability, developmental delay, or autism spectrum disorder.
• Family history of fragile X syndrome or related genetic disorders.
• Females with premature ovarian insufficiency or a family history of same.
• Males with primary ovarian insufficiency or characteristic physical and behavioral features of fragile X syndrome.

Preparation

• No special preparation like fasting is typically required.
• A detailed medical family history and pre-test counseling might be advised.
• Informed consent is usually obtained prior to the procedure.

Procedure Description

1. Blood Sample Collection: A blood sample is taken from the patient to extract DNA.
2. DNA Extraction and Amplification: The DNA is extracted from the blood cells and specific segments of the FMR1 gene are amplified using polymerase chain reaction (PCR) techniques.
3. Size Analysis: The number of trinucleotide repeats in the FMR1 gene is determined through various laboratory techniques like gel electrophoresis.
4. Methylation Analysis: The promoter region of the FMR1 gene is examined for abnormal methylation patterns using methods like methylation-specific PCR or Southern blotting.

Duration

The laboratory analysis may take several days to a few weeks to complete and process.

Setting

The initial blood sample collection is usually done at an outpatient clinic, hospital, or laboratory, while the genetic analysis is performed in a specialized genetic testing laboratory.

Personnel

• Phlebotomist or nurse for blood draw.
• Genetic counselors for pre- and post-test counseling.
• Medical geneticists and laboratory technologists for genetic analysis.

Risks and Complications

• The risk of complications is minimal and may include slight discomfort or bruising at the blood draw site.
• Rarely, there might be minor complications like hematoma or infection.

Benefits

• Accurate diagnosis of fragile X syndrome and related conditions.
• Helps guide medical management and intervention strategies.

• Provides valuable information for family planning and genetic counseling.

  Recovery

• There are no significant recovery requirements for the test itself.
• Patients can resume their normal activities immediately following the blood draw.

Alternatives

• Other genetic tests or screenings for different developmental disorders.
• Clinical evaluation and neuropsychological assessments.
• Each alternative has its pros and cons concerning specificity, sensitivity, and the scope of information provided compared to FMR1 gene analysis.

Patient Experience

• The procedure mainly involves a standard blood draw, which some patients might find slightly uncomfortable.

• Detailed genetic counseling may provide emotional support and comprehensive understanding during and after the test.

  The careful management of the procedure and follow-up in post-diagnosis scenarios ensure the patient’s comfort and provide valuable diagnostic clarity and direction.