What is Intrachromosomal translocation?

Intrachromosomal translocations involve the movement of a chromosomal segment from one location in the chromosome to another. This is normally non-reciprocal, that is another segment does not exchange places with the first segment.

What are the types of chromosomal translocation?

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 is oncogenic chromosomal translocation?

Chromosomal translocations are favored in neighboring chromosomes or genes in spatial proximity within the nucleus. Chromosomal translocations leading to cancer are generally via two ways, formation of oncogenic fusion protein or oncogene activation by a new promoter or enhancer.

What causes chromosomal translocations?

Translocations generally result from swapping of chromosomal arms between heterologous chromosomes and hence are reciprocal in nature (Figure 1) (8,9). DNA double-strand breaks (DSBs) are prerequisites for such translocations, although little is known about their generation.

What is a non reciprocal translocation?

Nonreciprocal translocations are one-way translocations in which a chromosomal segment is transferred to a nonhomologous chromosome. Reciprocal translocations, on the other hand, involve the exchange of segments from two nonhomologous chromosomes.

What is Intrachromosomal duplication?

Intrachromosomal duplication is the duplication of genes within the same chromosome over the course of evolution (a-1). Mutations may occur in the duplicated copy, such as observed with the substitution of Guanine with Adenine (a-2). Alignment of DNA sequences exhibits homology between the two chromosomes (a-3).

Why do chromosomal translocations happen?

What happens to a chromosome after a nonreciprocal translocation?

Nonreciprocal translocations on the other hand can lead to large deletions or duplications of chromosomal segments.

Are chromosomal translocations inherited?

A translocation is either inherited from a parent or happens around the time of conception. A translocation cannot be corrected – 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?

The most common translocation in humans involves chromosomes 13 and 14 and is seen in about 0.97 / 1000 newborns. Carriers of Robertsonian translocations are not associated with any phenotypic abnormalities, but there is a risk of unbalanced gametes that lead to miscarriages or abnormal offspring.

How many chromosomes are in the Robertsonian translocation?

45 chromosomes
45.2. Because counting the number of centromeres in a metaphase spread assesses chromosome number, individuals with a Robertsonian translocation have 45 chromosomes. The small reciprocal product, which contains the remnants of the short arms of the two fused chromosomes, is usually lost.

What is Robertsonian translocation give example?

A Robertsonian translocation results when the long arms of two acrocentric chromosomes fuse at the centromere and the two short arms are lost. If, for example, the long arms of chromosomes 13 and 14 fuse, no significant genetic material is lost—and the person is completely normal in spite of the translocation.

What is reciprocal and non reciprocal?

The main difference between reciprocal and nonreciprocal translocation is that reciprocal translocation is a two-way translocation responsible for the exchange of chromosomal segments between two nonhomologous chromosomes, whereas nonreciprocal translocation is a one-way translocation responsible for the movement of a …

What is the difference in reciprocal and nonreciprocal?

The key difference between reciprocal and nonreciprocal translocation is that reciprocal translocation is the exchange of broken DNA segments between two nonhomologous chromosomes, while nonreciprocal translocation is the transferring of a chromosome segment from one chromosome to another nonhomologous chromosome.

What is Intrachromosomal recombination?

What is Intrachromosomal Recombination? Intrachromosomal recombination is also known as non-homologous recombination that plays an important role in the mammalian biological systems. It is resulted due to crossing over between two linked gene pairs of two non-homologous chromosomes.

What is 15q duplication?

15q11-q13 duplication syndrome (dup15q syndrome) is a developmental disorder; its signs and symptoms vary among affected individuals. Poor muscle tone (hypotonia) is common in individuals with dup15q syndrome and contributes to delayed development and impairment of motor skills, including sitting and walking.