In genetics, chromosome translocation is a phenomenon that results in unusual rearrangement of chromosomes. This includes balanced and unbalanced translocation, with two main types: reciprocal-, and Robertsonian translocation.

How do I know if my translocation is balanced?

Sometimes a section from one chromosome of a particular pair changes places with a section from a chromosome of another pair. When the two breaks do not pass through a gene and there is no gain or loss of material when the chromosomes are looked at under a microscope, it is called a balanced translocation.

Can I have a healthy baby with balanced translocation?

People who carry a balanced translocation are usually healthy. The only time that a problem may arise is when that person tries to have children. A translocation is either inherited from a parent or happens around the time of conception.

What is balanced and unbalanced translocation?

Translocations can be balanced (in an even exchange of material with no genetic information extra or missing, and ideally full functionality) or unbalanced (where the exchange of chromosome material is unequal resulting in extra or missing genes).

What is a balanced rearrangement?

A balanced chromosomal rearrangement (or balanced chromosomal abnormality, BCA) is a type of chromosomal structural variant (SV) involving chromosomal rearrangements (e.g., translocations, inversions, and insertions) without cytogenetically apparent gain or loss of chromatin.

Understanding Chromosomal Translocation - Reciprocal Translocation v1.2

How do chromosomal translocations occur?

Translocations occur when chromosomes become broken during meiosis and the resulting fragment becomes joined to another chromosome. Reciprocal translocations: In a balanced reciprocal translocation (Fig. 2.3), genetic material is exchanged between two chromosomes with no apparent loss.

What is chromosomal rearrangement simple?

In genetics, a chromosomal rearrangement is a mutation that is a type of chromosome abnormality involving a change in the structure of the native chromosome. Such changes may involve several different classes of events, like deletions, duplications, inversions, and translocations.

What is a unbalanced translocation?

An unbalanced translocation occurs when a fetus inherits a chromosome with extra or missing genetic material from a parent with a balanced translocation.

What are the three types of translocation?

1. simple translocations (one break involved) 2. reciprocal translocations (two breaks involved) 3. shift type translocations (three breaks involved) 4.

When does unbalanced translocation occur?

Unbalanced translocations

If either parent carries a balanced translocation, it is possible that their child may inherit an unbalanced translocation in which there is an extra piece of one chromosome and/or a missing piece of another chromosome.

Are translocations inherited?

A translocation is either inherited from a parent or happens around the time of conception. A translocation cannot be corrected if it is present for life. A translocation is not something that can be "caught" from other people. Therefore a translocation carrier can still be a blood donor, for example.

How common are translocations?

Balanced chromosome translocations, in which sections of chromosomes change their geographical position on the chromosomal map without any loss or gain of important genetic material, are an important cause of recurrent miscarriages because they are common; one in 500 people carries a balanced translocation.

How many people have balanced translocations?

An estimated one in 560 people have a balanced translocation. It is not clear why balanced translocation occurs. It can be an inherited trait or can occur in a fetus even when neither parent is affected by the condition.

What are the consequences of balanced translocations?

Balanced translocation carriers are burdened with fertility issues due to improper chromosome segregation in gametes, resulting in either implantation failure, miscarriage or birth of a child with chromosomal disorders.

Does PGT a test for balanced translocation?

PGT-SR Plus is performed to determine which embryos carry a balanced translocation and which do not. These results are again sent to your physician where you may then select which embryo(s) to transfer.

Can PGD detect balanced translocation?

Studies performed previously indicate that array-based PGD can improve pregnancy rates in translocation carrier couples to between 45%-70% per transfer [12–14]. Despite this advantage, these traditional PGD methods can't distinguish balanced and structurally normal embryos from translocation carriers.

What are the types of translocations?

There are two main types of translocations: reciprocal and Robertsonian. In a reciprocal translocation, two different chromosomes have exchanged segments with each other. In a Robertsonian translocation, an entire chromosome attaches to another at the centromere.

What happens in translocations?

Translocations. A translocation occurs when a piece of one chromosome breaks off and attaches to another chromosome. This type of rearrangement is described as balanced if no genetic material is gained or lost in the cell. If there is a gain or loss of genetic material, the translocation is described as unbalanced .

What do you understand by translocations?

Translocation means a change in location. It often refers to genetics, when part of a chromosome is transferred to another chromosome. Chromosomes are structures that carry genes, our units of heredity. When this type of translocation occurs, it can cause flaws in chromosomes.

What are unbalanced chromosomes?

Unbalanced rearrangements include deletions, duplications, or insertions of a chromosome segment. Ring chromosomes can result when a chromosome undergoes two breaks and the broken ends fuse into a circular chromosome. An isochromosome can form when an arm of the chromosome is missing and the remaining arm duplicated.

What causes Triploidy?

What causes triploidy? Triploidy is the result of an extra set of chromosomes. This can occur when two sperm fertilizing one normal egg or a diploid sperm fertilizes a normal egg. It can also occur when a normal sperm fertilizes an egg that has an extra set of chromosomes.

What is a balanced Robertsonian translocation?

In balanced form, a Robertsonian translocation takes the place of two acrocentric chromosomes and results in no problems for the person carrying it. But in unbalanced form, Robertsonian translocations produce chromosome imbalance and cause syndrome of multiple malformations and mental retardation.

What does chromosomal rearrangement do?

There are two general types of rearrangements, balanced and imbalanced. Balanced rearrangements change the chromosomal gene order but do not remove or duplicate any of the DNA of the chromosomes. The two simple classes of balanced rearrangements are inversions and reciprocal translocations.

What is a result of chromosomal rearrangement?

Chromosome rearrangements can result in abnormal chromosomes with more than one centromere. These rearrangements, called dicentric chromosomes, can be unstable and undergo breakage during cell division if centromeres along one chromatid align and attach to microtubules originating from opposite spindle poles.

What is genome rearrangement?

Genome rearrangements are mutations that change the gene content of a genome or the arrangement of the genes on a genome. Several years of research on genome rearrangements have established different algorithmic approaches for solving some fundamental problems in comparative genomics based on gene order information.