#cytogenetics

Obesity-Cancer Link

A person carrying a mutation in either of the tumour suppressor proteins BRCA1 or BRCA2 is at increased risk of developing breast cancer. So too are people with obesity and diabetes. But whether obesity could exacerbate the risk in people with BRCA mutations was unknown. Recent research suggests that indeed metabolic and genetic risk can be cumulative. The image shows nuclei (blue) of milk duct cells from a person with a BRCA mutation with evidence of DNA damage shown in red. A study of such cells revealed the extent of DNA damage in BRCA mutation carriers positively correlated with body mass index. And blocking obesity related hormone signals in these cells could lessen such damage. The new findings suggest that while maintaining a low body weight is no guarantee of preventing breast cancer, addressing lifestyle, diet and metabolic health may be especially important for people already at increased genetic risk.

Written by Ruth Williams

Image from work by Priya Bhardwaj and colleagues

Department of Medicine, Weill Cornell Medicine, New York, NY, USA

Image copyright held by the original authors

Research published in Science Translational Medicine, February 2023

Rest in peace, Barbara McClintock.  A botanist by training, McClintock began studying cytogenetics, during which research she discovered genetic transposition (also known, familiarly, as jumping genes, wherein the genes themselves are responsible for turning characteristics on and off) by the 1950s, but because of the outcry against what was considered her unorthodox ideas, she stopped publishing her work.  Decades later, other scientists replicated her work, her hypotheses were proven, and she was (finally) awarded the Nobel Prize in Physiology or Medicine in 1983, the only woman to be thusly honored without sharing the prize.  She died on this date in 1992 at the age of 90.

Stamp details: Stamp on top: Issued on: May 4, 2005 From: New Haven, CT SC #3906

Cytogenetic testing is a specialized laboratory technique used to study chromosomes and identify structural or numerical abnormalities that may cause genetic disorders, cancers, or reproductive issues. By analyzing chromosomal changes at the cellular level, cytogenetic testing plays a crucial role in diagnosis, prognosis, and treatment planning across multiple medical specialties. With advances in laboratory technology, cytogenetic testing has become an integral part of modern diagnostic medicine.

What Is Cytogenetic Testing?

Cytogenetic testing involves the examination of chromosomes within cells to detect abnormalities such as extra or missing chromosomes, deletions, duplications, translocations, or inversions. Chromosomes contain DNA, which carries genetic instructions essential for normal growth and development. Any alteration in chromosomal structure or number can lead to disease.

Cytogenetic testing is commonly performed on samples such as blood, bone marrow, amniotic fluid, or tissue, depending on the clinical indication.

Why Is Cytogenetic Testing Important?

Cytogenetic testing provides valuable insights that cannot be obtained through routine laboratory tests. It is essential for:

Diagnosing chromosomal disorders

Identifying genetic causes of developmental delays and birth defects

Detecting chromosomal changes in cancers

Evaluating infertility and recurrent pregnancy loss

Guiding treatment decisions and prognosis

By revealing chromosomal abnormalities early, cytogenetic testing helps clinicians deliver accurate diagnoses and personalized patient care.

Types of Cytogenetic Testing

Several laboratory techniques are included under cytogenetic testing, each serving a specific purpose:

Karyotyping – Visual analysis of chromosomes to detect large structural or numerical abnormalities.

Fluorescence In Situ Hybridization (FISH) – Uses fluorescent probes to identify specific chromosomal changes with higher resolution.

Comparative Genomic Hybridization (CGH) – Detects gains and losses in chromosomal material across the genome.

Chromosomal Microarray Analysis (CMA) – A high-resolution method used for identifying submicroscopic chromosomal alterations.

These cytogenetic testing methods are selected based on clinical presentation and diagnostic requirements.

Clinical Applications of Cytogenetic Testing

Cytogenetic testing is widely used across various medical fields, including:

Prenatal Testing: Detects chromosomal abnormalities such as Down syndrome.

Oncology: Identifies cancer-related chromosomal changes in leukemia, lymphoma, and solid tumors.

Pediatrics: Evaluates genetic causes of developmental delay or congenital anomalies.

Reproductive Medicine: Assesses infertility, recurrent miscarriages, and implantation failure.

Its broad applicability makes cytogenetic testing an indispensable diagnostic tool.

How Cytogenetic Testing Works

The process of cytogenetic testing involves cell culture, chromosome preparation, staining or molecular probing, and microscopic or digital analysis. Highly trained laboratory experts examine chromosomal patterns to detect abnormalities and correlate findings with clinical information.

Advanced technologies have improved the sensitivity and accuracy of cytogenetic testing, enabling detection of even subtle genetic changes.

Cytogenetic Testing at Medgenome Labs

Medgenome Labs offers comprehensive cytogenetic testing services using advanced laboratory techniques and stringent quality standards. With a strong focus on precision and clinical relevance, Medgenome Labs supports diagnosis across prenatal, pediatric, oncologic, and reproductive indications.

Cytogenetic testing at Medgenome Labs is performed by experienced geneticists and laboratory specialists using state-of-the-art platforms. Detailed reporting and expert interpretation ensure that clinicians receive reliable, actionable insights to guide patient care. Medgenome Labs remains committed to delivering accurate and timely cytogenetic testing solutions aligned with evolving clinical needs.

Limitations of Cytogenetic Testing

While cytogenetic testing is highly valuable, it may not detect very small gene-level mutations. In some cases, it is complemented by molecular or sequencing-based tests to provide a complete genetic evaluation.

Conclusion