Tuesday, April 30, 2013

Cri-Du-Chat Syndrome

CRI-DU-CHAT SYNDROME

What is Cri-du-Chat syndrome?

The name of this syndrome is French for "cry of the cat," referring to the distinctive cry of children with this disorder. The cry is caused by abnormal larynx development, one of the many symptoms associated with this disorder. It usually becomes less noticeable as the baby gets older, making it difficult for doctors to diagnose cri-du-chat after age two. Cri-du-chat is caused by a deletion (the length of which may vary) on the short arm of chromosome 5. Multiple genes are missing as a result of this deletion, and each may contribute to the symptoms of the disorder. One of the deleted genes known to be involved is TERT (telomerase reverse transcriptase). This gene is important during cell division because it helps to keep the tips of chromosomes (telomeres) in tact.

How do people get Cri-du-Chat syndrome?

A deletion is caused by a break in the DNA molecule that makes up a chromosome. In most cases, the chromosome break occurs while the sperm or egg cell (the male or female gamete) is developing. When this gamete is fertilized, the child will develop cri-du-chat syndrome. The parent, however, does not have the break in any other cells of the body and does not have the syndrome. In fact, the break is usually such a rare event that it is very unlikely to happen again if the parent has another child.
It is possible for a child to inherit a broken chromosome from a parent who also had the disorder.

What are the symptoms of Cri-du-Chat syndrome?

Babies with cri-du-chat are usually small at birth, and may have respiratory problems. Often, the larynx doesn't develop correctly, which causes the signature cat-like cry.
People who have cri-du-chat have very distinctive features. They may have a small head (microcephaly), an unusually round face, a small chin, widely set eyes, folds of skin over their eyes, and a small bridge of the nose.
Several problems occur inside the body, as well. A small number of children have heart defects, muscular or skeletal problems, hearing or sight problems, or poor muscle tone. As they grow, people with cri-du-chat usually have difficulty walking and talking correctly. They may have behavior problems (such as hyperactivity or aggression), and severe mental retardation. If no major organ defects or other critical medical conditions exist, life expectancy is normal.

How do doctors diagnose cri-du-chat syndrome?

Doctors most often identify cri-du-chat by the infant's cat-like cry. Other signs are microcephaly, poor muscle tone, and mental retardation.

It is also possible to test for cri-du-chat (and other chromosomal abnormalitites) while the baby is still in its mother's womb. They can either test a tiny sample of tissue from outside the sac where the baby develops (chorionic villus sampling (CVS)), or they can test a sample of the amniotic fluid (amniocentesis).

How is cri-du-chat syndrome treated?

Although there is no real treatment for cri-du-chat syndrome, children with the disorder can go through therapy to improve their language skills, motor skills, and to help them develop as normally as possible.

Interesting facts about cri-du-chat syndrome

The geneticist Jerome Lejeune identified cri-du-chat syndrome in 1963. He also discovered the genetic abnormality that causes Down syndrome.
Cri-du-chat is one of the most common syndromes caused by a chromosomal deletion. It affects between 1 in 20,000 and 1 in 50,000 babies.
In 80 percent of the cases, the chromosome carrying the deletion comes from the father's sperm rather than the mother's egg.
When deletions occur during the formation of an egg or sperm, it is caused by unequal recombination during meiosis. Recombination normally occurs between pairs of chromosomes during meiosis while they are lined up at the metaphase plate. If the pairs of chromosomes don't line up correctly, or if the chromosome breaks aren't repaired properly, the structure of the chromosome can be altered. When unequal recombination occurs at this location on chromosome 5, it causes cri-du-chat syndrome.

Where can I go for more information on cri-du-chat syndrome?

5 P Minus Society

Source: http://learn.genetics.utah.edu/content/disorders/whataregd/cdc/

There is a part of the 5th chromosome pair missing.

Sunday, April 28, 2013

Synaesthesia

Synaesthesia: 1 in 2,000 people has an extraordinary condition in which the five senses intermingle

Why some see colours in numbers

There are many types of synaesthesia

US scientists say they can explain why some people 'see' colours when they look at numbers and letters.
As many as one in 2,000 people has an extraordinary condition in which the five senses intermingle, called synaesthesia.
Some see colours when they hear music or words. Others 'taste' words.
The study in Neuron tracked the brain activity of people with the most common form and found peaks in areas involved with perceiving shapes and colours.
Cross-wiring
The University of California San Diego team said their findings lend support to the idea that the condition is due to cross-activation between adjacent areas of the brain involved with processing different sensory information.
This cross-wiring might develop, they believe, by a failure of the "pruning" of nerve connections between the areas as the brain develops while still in the womb.

People with synaesthesia tend to want A to be red, S to be yellow and Z to be black

Synaesthesia researcher Dr Julia Simner, of the University of Edinburgh

For example, a person with synaesthesia might see red when they look at an ordinary figure '5' drawn in black ink on a white background because the red colour perception area of their brain is stimulated at the same time as the number recognition area.
The researchers conducted a series of experiments on volunteers with and without synaesthesia.
When the people without synaesthesia looked at letters and numbers only the brain areas involved with processing this information light up on brain activity scans.
In comparison, the people with synaesthesia had activity in colour perception regions as well.
Colour by numbers
Furthermore, some of the people with synaesthesia appeared to be better at 'seeing' colours than the others.
Those who had stronger colour perception had more activity in their colour perception brain areas.
Researcher Vilayanur Ramachandran said processes similar to synaesthesia might also underlie our general capacity for metaphor and be critical to creativity.
"It is not an accident that the condition is eight times more common among artists than the general population."
Dr Julia Simner, who has been studying synaesthesia at the University of Edinburgh along with colleagues at University College London, said the findings were supported by similar work looking at people who see colours when they hear sounds.
"Interestingly, we've recently analysed the letter-colour combinations of a very large number of people with synaesthesia and found that there are significant trends in their preferences.
"For example, people with synaesthesia tend to want A to be red, S to be yellow and Z to be black."
She said her research also revealed that people without synaesthesia have significant preferences for the colours of letters.
"Some of these choices were fairly obvious, such as 'O' being orange, but some were quite intriguing, and showed a similarity to those of people with synaesthesia."
Her findings are currently in press to appear in the journal Cognitive Neuropsychology.
Jennifer Green from the University of Cambridge, who has also been carrying out research in this area, said: "Some describe seeing the colours induced by letters and numbers as projected externally into space, while others report experiencing them internally, or in their 'mind's eye'. "This research lends further support to empirical evidence suggesting that these varying descriptions represent actual differences in the way synaesthesia occurs in individuals."

Source: http://news.bbc.co.uk/2/hi/health/4375977.stm

Can you hear colours?

Can you hear colours?
Can you smell pictures?
Does your alphabet have a colour?
What numbers are male?

For more in that, Follow up Annie's Health!

Friday, April 26, 2013

Tip of the day!

See if you're suitable for a Vaginal Birth after a cesarean!

VBAC: Vaginal Birth After a Caesarean!!!

Who can have vaginal birth after a caesarean?

http://www.yourparenting.co.za/pregnancy/birth/birth-options/going-natural-after-a-caesarean

Women going to labor without knowing they're pregnant!!!

Have you heard a story about women going to labor without knowing they're pregnant?
What was your first thought?
Mine: Yeah Right!
And yet here it is true as steel
http://video.answers.com/woman-gives-birth-six-hours-after-finding-about-her-pregnancy-517550374