Cytogenetics and Cancer Research

Cri du chat syndrome is a kind of genetic disorder that occurs when a small part of chromosomal material is missing from a particular region on chromosome 5.
 

Overview of Cri du Chat Syndrome

In 1963, Dr. Jerome Lejeune first described Cri du chat syndrome. It is named for the cat-like cry made by the patients with this genetic disorder. In French, Cri du chat means “cry of the cat”. Or we can call this syndrome as “5p minus syndrome”. This is because there is small deletion of genetic material from the short “p” arm of chromosome 5 to cause this unusual genetic disorder.
 

Features of Cri du Chat Syndrome

There are many unusual features for the infants with Cri du chat syndrome.

i. Cat-like cry (the most classic feature)

ii. Unusual facial features

iii. Poor muscle tone (hypotonia)

iv. Small head size (microcephaly)

v. Mental retardation

vi. Low birth weight

vii. Slow growth

viii. Congenital heart defects

ix. Language difficulties

x. Delayed motor skill development

xi. Behavioral problems (childish)
 

Genetic Basis of Cri du Chat Syndrome

The high-pitched mewing cry during infancy is caused by defective development of the larynx (organ in the throat which produced voice). The deleted part of chromosome 5 is essential for normal development. As we all know, human have 46 chromosomes in every single cell of our body. At the same time, we should have two copies of chromosome 5. However, individuals with Cri du chat syndrome have lost a small part of chromosome 5. There is a small piece of material has been deleted from the “p” arm of one of the chromosome 5. On the other hand, the deleted chromosomal material consists of many important genes for normal development. Because of losing these essential genes, the larynx, brain and other parts of body cannot function normally. Generally, the deletion is sporadic (occurs irregularly).
 

Diagnosis of Cri du Chat Syndrome

Yet, the cat-like cry from children with Cri du chat syndrome will becomes less noticeable when they get older. Therefore, we can just identify and diagnose this syndrome if a child with younger age has this unusual mewing cry. Chromosome analysis or karyotyping can provide the definitive diagnosis of Cri du chat syndrome by staining the chromosome and examining them under a microscope. FISH (fluorescence in-situ hybridisation) is useful and effective to detect a small deletion in chromosome like Cri du chat syndrome.
 
Unfortunately, there is still no cure for this syndrome. Nevertheless, the medical experts can still provide the supportive care and development therapy to the patients to make the things better. Once the unusual features are under controlled, most of them can live normally.
 
In conclusion, although there is still no cure for Cri du chat syndrome, we can still lessen the symptoms by receiving the suitable therapy.
 
I have to apologise as I seldom to update this Cytogenetics and Cancer Research blog recently. I’m busying doing my final year project in University of Malaya. However, I will try my best to keep on updating the blog. Thanks!

Peritoneal cancer is caused by carcinomatosis which occurs at the visceral and parietal peritoneal lining of the abdominal cavity. The tumour cells disseminate from their primary organ of origin to develop metastatic deposits on the visceral and parietal lining of the abdominal cavity. Therefore, it is important to find out the molecular events involved in peritoneal carcinomatosis to design the treatment to deal with the peritoneal cancer.
 
For better understanding on the events involved in peritoneal carcinomatosis, we need to look deeply on every single process of peritoneal cancer progression. We called this series of steps as “Peritoneal Metastatic Cascade”. Yet, we have to bear in mind that each step in the metastatic cascade does not occur in isolation but occur in a continuous and interdependent process.
 

Peritoneal Cancer Progression

1. At first, the tumour cells from the primary organ must break away from the primary tumour mass and gain access to the peritoneal cavity.
 
2. Then, the tumour cells free to disseminate around the peritoneal cavity.

 
3. There are many factors that determine the final destination of these tumour cells.

i. Gravity
 
ii. Movement of the abdominal viscera
 
iii. Flow of ascetic fluid
 
4. The tumour cells will first enter the innermost layer of peritoneum which is our mesothelium.
 
5. Next, the tumour cells will attach to the mesothelium.
 
6. Consequently, the mesothelial monolayer and its basement membrane will penetrate to the submesothelial connective tissue. The penetration provides the chance to the tumour cells to access to the submesothelial connective tissue too.
 
7. Continuously, the invasion of the underlying connective tissue gives the necessary scaffold for tumour proliferation and provides tumour-stromal interaction.
 
8. The discrete metastatic tumour deposit starts to establish.
 
9. Finally, the induction of angiogenesis to sustain tumour proliferation has enabled the further metastatic growth of peritoneal cancer cells.
 
In conclusion, peritoneal cancer is a rare cancer that still needs a lot of research for further understanding. I decide to write about it in Cytogenetics and Cancer Research blog because it is interesting to look on. I will try to find out more information about peritoneal cancer and write it out here. Stay tuned!

( Resource: Cancer Treatment and Research by Steven T. Rosen)
 

Have you heard about peritoneal cancer before? Any extra useful information to share with us?