Name of the Procedure:

Fetal Chromosomal Microdeletion(s) Genomic Sequence Analysis (e.g., DiGeorge syndrome, Cri-du-chat syndrome), Circulating Cell-Free Fetal DNA in Maternal Blood

Summary

This procedure involves analyzing small pieces of fetal DNA that circulate in a pregnant woman's blood to detect chromosomal microdeletions that can indicate genetic disorders, such as DiGeorge syndrome or Cri-du-chat syndrome.

Purpose

The procedure is used to screen for specific genetic abnormalities in the fetus, particularly those involving small deletions in chromosomes that may lead to developmental and health issues. The goal is early detection to offer timely medical interventions or to inform parental decisions.

Indications

• A prior child or family history of chromosomal microdeletions.
• Abnormal results from other prenatal tests (e.g., ultrasound findings).
• Advanced maternal age.
• Parents known to be carriers of certain genetic conditions.

Preparation

• No special preparation is typically required.
• Patients may be advised to avoid certain medications before the blood draw.
• An initial consultation with a genetic counselor may be recommended.

Procedure Description

1. A blood sample is drawn from the pregnant woman.
2. Circulating cell-free fetal DNA fragments are isolated from the maternal blood.
3. The DNA fragments are sequenced and analyzed using advanced genomic technologies to detect specific microdeletions.
4. Results are interpreted by specialists and discussed with the parents.

Tools used include:

• Phlebotomy supplies for the blood draw.
• Specialized laboratory equipment for DNA extraction and sequencing.

Duration

The blood draw itself takes about 10-15 minutes. Laboratory analysis and results may take from one to several weeks.

Setting

The initial blood draw is typically done in an outpatient clinic, laboratory, or hospital.

Personnel

• Phlebotomist or nurse for the blood draw.
• Genetic specialists and laboratory technicians for DNA analysis.
• Genetic counselor for pre- and post-procedure discussions.

Risks and Complications

• Minor risks associated with blood draw: bruising, infection, or discomfort at the puncture site.
• False positive or false negative results, leading to anxiety or missed diagnosis.
• Requires follow-up diagnostic tests for confirmation.

Benefits

• Early detection of potential genetic disorders.
• Informed decision-making for expectant parents.
• Planning for potential medical interventions post-birth.
• Non-invasive compared to other prenatal diagnostic tests.

Recovery

• No recovery time required from the blood draw.
• Follow-up visits may be necessary to discuss results and next steps.

Alternatives

• Chorionic villus sampling (CVS) or amniocentesis for direct genetic testing of fetal cells (more invasive but definitive).
• Standard ultrasound screening.

Patient Experience

• The blood draw is similar to any other standard blood test: quick and relatively painless, although some patients might feel anxious or uncomfortable.
• Post-procedure, patients may feel anxious while waiting for results but genetic counseling can provide support.