On the 12th Day of Trisomy Awareness...Structural Abnormalities!

DAY 12: 

On our 12th day of MARCHING into TRISOMY AWARENESS MONTH, we are going to share in more detail about STRUCTURAL ABNORMALITIES. This means that the chromosome's structure is altered, and this can come in several forms such as deletions, duplications, translocations, inversions, insertions, and rings. 

• DELETION is when a portion of the chromosome is missing or deleted. Known disorders in humans include Wolf-Hirschhorn syndrome, which is caused by partial deletion of the short arm of chromosome 4. Jacobsen syndrome is also called the terminal 11q deletion disorder. 
• DUPLICATION is when a portion of the chromosome is duplicated, resulting in extra genetic material. Known human disorders include Charcot-Marie-Tooth disease type 1A which may be caused by duplication of the gene encoding peripheral myelin protein 22 (PMP22) on chromosome 17. 
• TRANSLOCATION is when a portion of one chromosome is transferred to another chromosome. There are two main types of translocations; Reciprocal translocation is when segments from two different chromosomes have been exchanged, and Robertsonian translocation is when an entire chromosome has attached to another at the centromere - in humans these only occur with chromosome 13, 14, 15, 21 and 22. 
• INVERSION is when a portion of the chromosome has broken off, turned upside down and reattached, therefore the genetic material is inverted. 
• INSERTION is when a portion of one chromosome has been deleted from its normal place and inserted into another chromosome. 
• RING is when a portion of a chromosome has broken off and formed a circle or ring. This can happen with or without loss of genetic material. 

The sample picture attached shows an example of how these structural abnormalities compare to the normal. Share because you Care ♥

Visit Hope for Trisomy on Facebook for more interesting facts about chromosomes and trisomy!

Getting Down With Chromosomes

Day 4 Share: 

On our 4th day of MARCHING into TRISOMY AWARENESS MONTH, we are going to share an interesting FACT about chromosomes. We all have learned that Trisomy is a chromosome disorder, but does everyone know what a chromosome is? A chromosome is a threadlike strand of DNA in the cell nucleus that carries the genes in a linear order. Each chromosome carries genes that contain the hereditary material that controls the growth and characteristics of the body. There are 46 chromosomes in each human cell organized in 23 pairs, of which 22 pairs are similar in appearance but differ at the molecular level. Here is the interesting fact; the chromosomes are designated by a number beginning with chromosome 1 being the longest, followed by chromosome 2, etc. So as the numbers get higher, the chromosome gets smaller as you can see in the sample picture. Share because you Care. ♥

Day 5 Share: 

On our 5th day of MARCHING into TRISOMY AWARENESS MONTH, we are going to share a little more about chromosomes. Did you know that a chromosome has ARMS? Well...it does. All human chromosomes have 2 arms -- a short arm and a long arm -- that are separated from each other only by the centromere, the point at which the chromosome is attached to the spindle during cell division. The short arm is termed the "p arm" while the long arm of the chromosome is termed the "q arm." The symbol "p" was chosen to designate the short arm because "p" stands for "petit", "small" in French. The letter "q" was selected to signify the long arm merely because "q" is the next letter in the alphabet. Share because you Care. ♥