Fertility NEWS LETTER

Ideal fertility : ICSI / IVF & Genetic Center India

Vol IV Issue 9, September 2007

In This issue

  1. Chromosomes : The basic knowledge
  2. Gene and Diseases
  3. Training in IVF and Embryology

In Previous Issue

  1. Who needs Genetic counseling?
  2. How to prevent LH surge in stimulated IUI ?
  3. First national training program on IVF and Embryology conducted successfully.

Dear Colleges
Hello

Another news letter with different topics. There is a paucity of any journal dealing with researches and case presentations related to human genetics and prenatal diagnosis which correlates with human reproduction. Our news letter is very minute step towards that . Some day our faculty members dealing with this area may help it and it may grow to a full fledged peer reviewed journal.

Cytogenetics and molecular genetics are very intimate part of fetal medicine and human disease diagnosis. The days are coming when all the medical disorders will be preempted and their confirmation will base on molecular genetics. The knowledge of these areas will help a medial practitioner a great extent.

We are dealing with two related topics which acts as basic framework for this . We are planning our set-up for FISH ( Fluorescent in-situ Hybridization )very soon.

We feel ,it will be a great help for diagnosing fetal defects and for cancer genetics.

Accept my best wishes

Sincerely yours

With best wishes
Dr. D’Pankar Banerji

(Click Archives for Earlier issues)

Chromosomes : The basic knowledge

What Are Chromosomes?

Cytogenetics is the study of chromosomes and the related disease states caused by abnormal chromosome number and/or structure. Chromosomes are complex structures located in the cell nucleus, they are composed of DNA, histone and non-histone proteins, RNA , and polysaccharides. They are basically the "packages" that contain the DNA. Normally chromosomes can't be seen with a light microscope but during cell division they become condensed enough to be easily analyzed at 1000X. To collect cells with their chromosomes in this condensed state they are exposed to a mitotic inhibitor which blocks formation of the spindle and arrests cell division at the metaphase stage.

A variety of tissue types can be used to obtain chromosome preparations. Some examples include peripheral blood, bone marrow, amniotic fluid, and products of conception.

Chromosome Morphology

Under the microscope chromosomes appear as thin, thread-like structures. They all have a short arm and long arm separated by a primary constriction called the centromere. The short arm is designated as p and the long arm as q. The centromere is the location of spindle attachment and is an integral part of the chromosome. It is essential for the normal movement and segregation of chromosomes during cell division. Human metaphase chromosomes come in three basic shapes and can be categorized according to the length of the short and long arms and also the centromere location. Metacentric chromosomes have short and long arms of roughly equal length with the centromere in the middle. Submetacentric chromosomes have short and long arms of unequal length with the centromere more towards one end. Acrocentric chromosomes have a centromere very near to one end and have very small short arms. They frequently have secondary constrictions on the short arms that connect very small pieces of DNA, called stalks and satellites, to the centromere. The stalks contain genes which code for ribosomal RNA.

The diagrams, called ideograms*, of G-banded chromosomes 1, 9, and 14 are typical examples of metacentric, submetacentric, and acrocentric chromosomes respectively. The ideogram is basically a "chromosome map" showing the relationship between the short and long arms, centromere (cen), and in the case of acrocentric chromosomes the stalks (st) and satellites (sa). The specific banding patterns are also illustrated. Each band is numbered to aid in describing rearrangements.

Chromosome Analysis

Virtually all routine clinical Cytogenetic analyses are done on chromosome preparations that have been treated and stained to produce a banding pattern specific to each chromosome. This allows for the detection of subtle changes in chromosome structure. The most common staining treatment is called G-banding. A variety of other staining techniques are available to help identify specific abnormalities. Once stained metaphase chromosome preparations have been obtained they can be examined under the microscope. Typically 15-20 cells are scanned and counted with at least 5 cells being fully analyzed. During a full analysis each chromosome is critically compared band-for-band with it's homology. It is necessary to examine this many cells in order to detect clinically significant mosaicism (see below).

Following microscopic analysis, either photographic or computerized digital images of the best quality metaphase cells are made. Each chromosome can then be arranged in pairs according to size and banding pattern into a karyotype. The karyotype allows the Cytogeneticist to even more closely examine each chromosome for structural changes. A written description of the karyotype which defines the chromosome analysis is

Metacentric
(Chromosome 1)
Submetacentric
(Chromosome 9)
Acrocentric
(Chromosome 14)

Gene and Diseases

How does a faulty gene trigger disease?

A sound body depends on the continuous interplay of thousands of proteins, acting together in just the right amounts and in just the right places - and each properly functioning protein is the product of an intact gene. Genes can be altered (mutated) in many ways. The most common gene mistake involves a single changed base in the DNA - a misspelling. Other alterations include the loss or gain of a base. Sometimes long segments of DNA are multiplied or disappear.

Some mutations are silent; they affect neither the structure of the encoded protein nor its function. Other mutations result in an altered protein. In some instances, the protein is normal enough to function, but not well; this is the case of the flawed hemoglobin, the oxygen-carrying protein in the blood that causes sickle-cell anemia. In other instances, the protein can be totally disabled. The outcome of a particular mutation depends not only on how it alters a protein's function but also on how vital that particular protein is to survival.

How do gene mistakes occur?

Gene mutations can be either inherited from a parent or acquired. A hereditary mutation is a mistake that is present in the DNA of virtually all body cells. Hereditary mutations are also called germline mutations because the gene change exists in the reproductive cells (germ cells) and can be passed from generation to generation, from parent to newborn. Moreover, the mutation is copied every time body cells divide.
Acquired mutations, also known as somatic mutations, are changes in DNA that develop throughout a person's life. In contrast to hereditary mutations, somatic mutations arise in the DNA of individual cells; the genetic errors are passed only to direct descendants of those cells. Mutations are often the result of errors that crop up during cell division, when the cell is making a copy of itself and dividing into two. Acquired mutations can also be the byproducts of environmental stresses such as radiation or toxins.

Mutations occur all the time in every cell in the body. Each cell, however, has the remarkable ability to recognize mistakes and fix them before it passes them along to its descendants. But a cell's DNA repair mechanisms can fail, or be overwhelmed, or become less efficient with age. Over time, mistakes can accumulate.

What is gene testing?

Gene testing involves examining a person's DNA - taken from cells in a sample of blood or, occasionally, from other body fluids or tissues - for some anomaly that flags a disease or disorder. The DNA change can be relatively large: a missing or added piece of a chromosome - even an entire chromosome - that is visible under a microscope. Or it can be extremely small, as little as one extra, missing, or altered chemical base. Genes can be over expressed (too many copies), inactivated, or lost altogether. Sometimes, pieces of chromosomes become switched, or transposed, so that a gene ends up in a location where it is permanently and inappropriately turned on or off.

In addition to studying chromosomes or genes, genetic testing in a broader sense includes biochemical tests for the presence or absence of key proteins that signal aberrant genes.

What are the uses of genetic testing?

Genetic tests can be used to look for possible predisposition to disease as well as to confirm a suspected mutation in an individual or family.

The most widespread type of genetic testing is newborn screening. Carrier testing can be used to help couples to learn if they carry - and thus risk passing to their children - a recessive allele for inherited disorders such as cystic fibrosis, sickle-cell anemia, or Tay-Sachs disease (a lethal disorder of lipid metabolism). Genetic tests - biochemical, chromosomal, and DNA-based - also are widely available for the prenatal diagnosis of conditions such as Down syndrome.

Much of the current excitement in gene testing, however, centers on predictive gene testing: tests that identify people who are at risk of getting a disease, before any symptoms appear. Tests are already available in research programs for some two dozen such diseases, and as more disease genes are discovered, more gene tests can be expected.

Training in IVF and Embryology

Module I : Ovulation induction and Intra Uterine Insemination ( One day )
Module II : Conventional IVF and fundamentals of Embryology( Two days )
Module III : Intra cytoplasmic sperm injection, Micro manipulation ( Two days )

Course Objectives:

The purpose of the course will be to provide an avenue for participants to enter into the field of reproductive biology and an opportunity to gain greater appreciation of the biological processes of mammalian reproduction .At the end of the course, the participants should able to do In-vitro Fertilization of mammalian oocyte.

Course Details :

  1. Basic reproductive endocrinology of male and female
  2. Ovulation induction and controlled ovarian Hyperstimulation .
  3. Sperm preparation methods
  4. Fundamentals of embryology
  5. Meiosis and its genetic aspect
  6. Gametogenesis
  7. The development of Assisted reproduction technology
  8. IVF culture media and techniques
  9. Quality control of embryology lab
  10. Handling and culture of Oocytes
  11. Stereo zoom and inverted microscopy and photomicrography
  12. Setting of the micro manipulators.
  13. Intra cytoplasmic Sperm Injection
  14. Students will have practical hands on experience in this field and supposed to complete their task and submit a project report at the end.
  15. Library and internet facilities will be provided as required.

Course fees :

Module I : Rs.2000.00 ( US$ 50 )
Module II : Rs.20,000.00 ( US$ 500 )
Module III : Rs. 50,000.00 ( US$ 1250 )

For Module I and II Rs.20,000 ( US$ 500 )
For all the three modules/Module II and III : Rs.55,000.00 ( US$ 1375 )

Payments :
Draft : in the name of Dr. D’Pankar Banerji,payable at Jabalpur

Accommodation :
Participants can be provided accommodation in nearby hotels at an extra cost ,Range is Rs.700-3000 per day

Lunch will be served without an extra cost

Timing :
10.00 am to 5.00 pm

ONLY TWO PARTICIPANTS PER BATCH FOR MODULE II AND III

Dates :
Throughout the year.

Course Directors :
Dr. D’Pankar Banerji,IVF specialist and Dr.Mrs.Rinku Banerji,Embryologist and molecular pathologist.

Archives