Common steps include:

Cell culture: Cells are grown in the lab to allow chromosomes to be visible.

Harvesting and staining: Cells are stopped during division (metaphase), and chromosomes are stained to reveal banding patterns.

Microscopy or digital imaging: Chromosomes are analyzed for abnormalities.

Advanced methods also include:

FISH (Fluorescence In Situ Hybridization): Uses fluorescent probes to detect specific DNA sequences.

Array CGH and karyotyping: High-resolution techniques to detect gains or losses of chromosomal material.

Types of Chromosomal Abnormalities Detected

1. Numerical Abnormalities
Extra or missing chromosomes

Example: Down syndrome (Trisomy 21), Turner syndrome (45,X)

2. Structural Abnormalities
Translocations – rearrangement of chromosome parts.

Deletions – loss of a chromosome segment.

Duplications – extra copies of a chromosome segment.

Inversions – reversed segments within a chromosome.

Ring chromosomes – chromosomes form a ring due to deletions.

Why Cytogenetics Matters

🧬 1. Diagnosing Genetic Disorders
Cytogenetics is key in diagnosing inherited and developmental disorders, such as:

• Down syndrome
• Turner syndrome
• Klinefelter syndrome
• DiGeorge syndrome
• Edwards and Patau syndromes

Early diagnosis can guide medical care, support, and counseling.

👶 2. Prenatal Testing
Cytogenetics is used in prenatal screening to detect chromosomal abnormalities in fetuses, using samples from:

• Amniotic fluid (amniocentesis)
• Chorionic villi (CVS)

This helps expectant parents make informed decisions and plan for medical care.

👩‍⚕️ 3. Infertility and Recurrent Miscarriage Evaluation
Some chromosomal abnormalities, especially balanced translocations, may not cause symptoms but can lead to repeated miscarriages or infertility. Cytogenetic testing can help identify these hidden issues.

🧫 4. Cancer Diagnosis and Prognosis
Cytogenetics is essential in oncology to detect chromosomal changes associated with:

Leukemia (e.g., Philadelphia chromosome in chronic myeloid leukemia)

Lymphoma

Solid tumors (e.g., Ewing sarcoma)

These findings help determine prognosis and guide targeted therapies.

🧠 5. Intellectual Disabilities and Developmental Delay
In children with developmental delays, learning disabilities, or autism spectrum disorder, cytogenetic analysis can uncover underlying genetic causes, allowing for early intervention and management.

🧪 6. Personalized Medicine
Chromosome studies help tailor treatments based on a patient’s genetic profile—especially in cancer care and reproductive medicine.