What Are Chromosome Rearrangements?

Chromosome rearrangements are structural changes that alter the normal configuration of chromosomes. These changes can involve large segments of DNA — from thousands to millions of base pairs — and can occur spontaneously, be inherited, or result from exposure to mutagens (like radiation or chemicals).

Common Types of Rearrangements:

1. Deletions – Loss of a chromosome segment

2. Duplications – Repetition of a segment

3. Inversions – A segment breaks off, flips, and reattaches

4. Translocations – Segments exchange places between non-homologous chromosomes

5. Insertions – A segment is inserted into another part of the genome

These changes can disrupt genes directly or affect gene regulation, leading to disease.

How Do Chromosome Rearrangements Cause Disease?

The impact of a rearrangement depends on which genes are involved, how much DNA is affected, and when the rearrangement occurs (in development vs. adulthood). Here are some key mechanisms:

• Gene disruption: Breaking a gene can lead to loss of function or the creation of a non-functional protein.

• Gene fusion: Joining parts of two genes may form a novel hybrid gene with new functions (common in cancer).

• Dosage effects: Extra or missing gene copies can disturb the balance of gene expression.

• Position effects: Moving a gene to a new regulatory environment may silence or over-activate it.

Chromosome Rearrangements in Human Disease

1. Developmental Disorders

• Cri-du-chat syndrome: Caused by a deletion on chromosome 5p. Affected infants often have a high-pitched cry and intellectual disability.

• Williams syndrome: Results from a microdeletion on chromosome 7q, affecting genes related to cardiovascular and cognitive function.

2. Cancer

Cancer is perhaps the most striking example of disease caused by chromosome rearrangements.

• Chronic Myeloid Leukemia (CML): Caused by a translocation between chromosomes 9 and 22, forming the Philadelphia chromosome. This creates the BCR-ABL fusion gene, which drives uncontrolled cell growth.

• Burkitt lymphoma: Involves translocation of the MYC gene, leading to excessive cell division.

• Ewing sarcoma: A fusion of EWSR1 and FLI1 genes through translocation promotes tumor development.

3. Infertility and Miscarriages

Balanced rearrangements (like inversions or translocations) in carriers may not cause disease directly but can result in:

• Recurrent miscarriages

• Infertility

• Birth defects in offspring

Detecting Rearrangements

Thanks to modern genomics, chromosome rearrangements can now be detected with high precision using:

• Karyotyping – Classic method for detecting large rearrangements

• FISH (Fluorescence In Situ Hybridization) – Uses fluorescent probes to target specific DNA sequences

• Array CGH (Comparative Genomic Hybridization) – Detects copy number changes across the genome

• Whole Genome Sequencing (WGS) – Identifies even small or complex rearrangements at base-pair resolution

Looking Forward: The Future of Chromosome Medicine

Understanding chromosome rearrangements is now central to:

• Personalized medicine

• Genetic counseling

• Targeted therapies, especially in cancer (e.g., tyrosine kinase inhibitors for BCR-ABL fusion)

With the rise of long-read sequencing and single-cell genomics, even previously “invisible” rearrangements are being uncovered, offering new insights into both rare diseases and common conditions.

Final Thoughts

Chromosome rearrangements remind us that genetics isn't just about which genes we have — but where they are, how they're arranged, and when they're active. As our tools grow sharper, so does our ability to diagnose, understand, and treat diseases rooted in genomic architecture.

In a way, the genome is like a book not just defined by its words, but also by how the chapters are ordered. Rearranging them can create a new story — sometimes harmful, sometimes insightful — and understanding these changes is key to writing a healthier future.

Research Area

Investigating the role in disease of both the microbe and its host (i.e immune system failure), using genomics and systems biology-based approaches
Using genomics and network analysis to characterize disease outbreaks and their environmental/social/genetic causes, and
Identifying new anti-infective and immune modulating therapies/biomarkers.

Link @ http://www.brinkman.mbb.sfu.ca/

The next step after reading genetic code is writing a script to analyse and explore the hidden information. This tutorial is aimed to introduce you new biological programming languages with their packages/libraries, and assist in your scripting work.

Navigate the sub-section of this page [ see right hand side of the page for it ]

For more information visit: http://www.snubi.org/TBC2013/

SciGenom Research Foundation (SGRF) and Institute of Genomics and Integrative Biology (IGIB) are pleased to host the Next-Generation Sequencing and Bioinformatics for Genomics & Healthcare conference.

In the ten years since the first human reference genome was completed for US$3 billion the sequencing technologies have radically changed leading to great reduction in sequencing cost. Today a human genome can be sequenced for under US$ 5000 in less than two weeks. It is expected that by the end of 2015 the cost of sequencing a human genome will drop to below thousand dollars. The next generation sequencing technologies over the past five years have enabled a large number of genomic studies that impact human health and disease. Also, this has made possible the growth of microbial, animal and plant genomics studies. While the data production has increased at a rapid pace challenges remain in analyzing and understanding the data. The conference will cover the next generation sequencing (NGS) technologies, bioinformatics for NGS and applications of NGS in many areas including personalized medicine.

For more info : http://www.scigenomconferences.com/2013/default.php

Biocon, India's largest publicly-held biotechnology firm, launched its second novel 'lab-to-market' molecule, Alzumab, to treat chronic plaque psoriasis at a cost 50 per cent lower than the existing one.

Biocon is bringing Alzumab (a biologic) in the form of a vial after working on it for nearly a decade. The work had initially started in a joint effort with the Center of Molecular Immunology, Havana, but Biocon took control of the programme soon after and also bought out its partner a few years ago. Biocon tell to the media that genotypic played a critical role in functional studies and clinical trial Genomics.

The Biocon drug, at around ₹ 7,500 a vial, will cost half as much as the currently available drugs - from Pfizer and J&J - to treat psoriasis, a skin disease that causes rough red areas where the skin comes off in small pieces. A patient is usually prescribed to consume more than 40 vials in a 24-week course.

17 Nov 2013 -22 Nov 2013

More at http://events.embo.org/13-large-scale-data/

Online Registration: https://www.conference-service.com/pc13-47/welcome.cgi

Blog : http://blogs.plos.org/biologue/2012/12/28/translational-bioinformatics-plos-computational-biology-presents-an-educational-resource-for-an-emerging-field/

Educational Material : http://www.ploscollections.org/article/browseIssue.action?issue=info:doi/10.1371/issue.pcol.v03.i11

Address of the bookmark: http://www.ploscollections.org/article/browseIssue.action?issue=info:doi/10.1371/issue.pcol.v03.i11

An exciting opportunity exists for a highly motivated and enthusiastic bioinformatics researcher to work in the Exosome, Secretome and Systems Biology laboratory of Dr Suresh Mathivanan. This position is funded through the National Institutes of Health (NIH) USA, to study the role of extracellular RNA or ExRNA in intercellular communication.

The successful applicant will be involved in collaborative bioinformatics research with more than 30 American Universities/Institutes. The ExRNA consortium is a multi-institute USD 17 million funded program which has 5 primary aims: to understand the biogenesis of ExRNA (vesicles and non-vesicles), to explore the use of ExRNA in biomarker research, to establish a reference profile of ExRNA in various disease conditions, to explore the role of ExRNA in therapeutic purposes and to manage the generated data through a reference portal. The bioinformatics component is critical in managing and analysing the data generated by the entire consortium. The researcher is required to contribute to the management and perform the analysis of ExRNA data.

The candidate to succeed, you will possess:

Experience in the analysis and modelling of data, including the capacity to integrate data from a range of sources and of uneven quality.

Evidence of experience in research and of the ability to work effectively under limited supervision or independently.

A record of contribution to publications, conference papers and/or reports, or professional or technical contributions which provide evidence of research potential.

Completion of a doctoral degree in bioinformatics or biostatistics with a focus on transcriptomic data will be highly regarded.

Preference will be given to applicants with competence in programming (JavaScript, Perl/Python), any web-based applications (PHP, ZOPE) and relational databases (MySQL).

Closing date: 30 September 2013

Position Enquiries: Dr Suresh Mathivanan (s.mathivanan@latrobe.edu.au)

More at http://www.mathivananlab.org/