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Monday, 19 November 2007

Put your questions about genetics here, and I will try to answer them

guinness413 NJ
11/14/07
Can you take Mylanta while pregnant and if not, what can you take for stomach upset while pregnant that is safe


DNA Direct-LK,MS,CGC
//
11/19/07
I am sorry that your question cannot be answered in the genetics forum. You may want to ask your health care provider.

praspowt
to guinness 413
Mylanta has a generic name "SIMETHICONE" It is safe to use during pregnancy. It is a question that geneticist should answer, because we have to deal with dysmorphic child that may cause from many teratogenic agents, drugs. (Most common one . Can u guess?.Alcohol).
Praspowt11/19/07
http://clinicalgenetics.blogspot.com

Put your questions about genetics here, and I will try to answer them

The example of my answer from another forum

lala0711/18/07

i last had my period in early aug.for three days then stoped. i also stoped taking birth control in aug. its now november and still no period. i've takin a home test which came up negative but im recieving sore breast, nausea, cravings,heartburn, and headaches. i can't go to the doctor because i have no insurance.i know a missed period can be from stress. i'm a teen who lives alone with her boyfried and i'm a cna at a nursing home so i know theres chances of being stressed. i'm not sure what to do. could someone please explain a little of whats going on. could i be prgnant or what?

Praspowt11/19/07
To lala07
u miss your period since August, the pregnancy test will almost positive, if u get preg since then. But try to test it in a few days for sure. the question is why u stop birth pills? u'd better have more safe sex with condom use and you have to be more aware about your birth control plan. If test negative you can start your birth pills again (don't forgewt safe sex) and wait for another month to have new cycle of period. Is this help? http://clinicalgenetics.blogspot.com

Let's share experience about genetic disorders

This is a story of a families suffered from hereditary non polyposis colon cancer that was left undiagnoses for a long period.
The index patient is a 68 yr old women. She came to thyroid clinic as a regular basis to reevaluate her neck mass that was diagnosis later as benign hyroid nodule for about 2 years. Last time, my resident asked her about her family, and this resident found that this is a very interesting family. She was diagnosed transitional cell carcinoma of left kidneys and was undergone success total nephrectomy for 20 years. She also had undergone hysterectmy (cut out the womb) that was diagnosed benign smooth muscle tumor. Her brother was suffered from small intestinal adenocardinoma in his 40 years. She had 5 offsprings, two males and three females. Her son was healthy, her daughters are diagnosed ovarian cancer and colon cancer each. Left only one daughter in her 40 normal.
So this family had four members suffered from cancers which can be group to fit for hereditary non polyposis colon cancer syndrome, which is a cancer predisposing syndrome. Member who carried the abnormal gene have about 70% risk to developed colon cancer and a substantial risks to develop other tumors such as kidneys, ovaries, small intestines like this family.
The family memebers were arranged to see me. I gave them a new information that they never heard before. Surveillance colonoscopy (only the index patient go for virtual CT colonoscopy), pelvic ultrasound, serum tumor marker screening are recommended for patients and who are at 50% risk to carrier the mutated gene.
Genetic testing of this syndrome is very exhaustive, due to different genes (up to 4 or more) can be the cause of the syndrome, very large gene and many other limited factors, so this genetic test are not adopted as routine practice in our country.
The family member said " We feel that we are lucky to know this information. For more than 20 years, we see our relatives diagnosed with cancer and we cannot do anything. Now we know that genetics play important part and we can surveillance as a regular basis to find it and to manage it promptly. We are happier that we were."

Is cancer a genetic disorders?

What is cancer?
Cancer is a disease of the cells in the body. There are many different types of cell in the body, and many different types of cancer which arise from different types of cell. What all types of cancer have in common is that the cancer cells are abnormal and multiply 'out of control'. However, there are often great differences between different types of cancer. For example:
Some grow and spread more quickly than others.
Some are more easy to treat than others, particularly if diagnosed at an early stage.
Some respond much better than others to chemotherapy, radiotherapy, or other treatments.
Some have a better outlook (prognosis) than others. For some types of cancer there is a very good chance of being cured. For some types of cancer, the outlook is poor.
So, cancer is not just one condition. In each case it is important to know exactly what type of cancer has developed, how large it has become, whether it has spread, and how well the particular type of cancer responds to various treatments. This will enable you to get reliable information on treatment options and outlook.

What causes cancer?
Each cancer is thought to first start from one abnormal cell. What seems to happen is that certain vital genes which control how cells divide and multiply are damaged or altered. This makes the cell abnormal. If the abnormal cell survives it may multiply 'out of control' into a malignant tumour.
We all have a risk of developing cancer. Many cancers seem to develop for no apparent reason. However, certain risk-factors are known to increase the chance that one or more of your cells will become abnormal and lead to cancer. Risk factors include the following:
Chemical carcinogens
A carcinogen is something (chemical, radiation, etc) which can damage a cell and make it more likely to turn into a cancerous cell. As a general rule, the more the exposure to a carcinogen, the greater the risk. A list of known and suspected chemical carcinogens can be found at http://physchem.ox.ac.uk/MSDS/carcinogens.html Well known examples include:
Tobacco smoke. If you smoke, you are more likely to develop cancer of the lung, mouth, throat, oesophagus, bladder and pancreas. Smoking is thought to cause about a quarter of all cancers. About 1 in 10 smokers die from lung cancer. The heavier you smoke, the greater the risk. If you stop smoking, your risk goes down con
siderably.
Workplace chemicals such as asbestos, benzene, formaldehyde, etc. If you have worked with these without protection you have an increased risk of developing certain cancers. For example, a cancer called mesothelioma is linked to past exposure to asbestos.
Age The older you become, the more likely that you will develop a cancer. This is probably due to an accumulation of damage to cells in the body over time. Also, the body's defences and resistance against abnormal cells may become less good as you become older. For example, the ability to repair damaged cells, and the immune system which may destroy abnormal cells, may become less efficient with age. So, eventually one damaged cell may manage to survive and multiply 'out of control' into a cancer. Most cancers develop in older people.
Lifestyle factors
Diet and other lifestyle factors may increase or decrease the risk of developing cancer. For example:
If you eat a lot of fruit and vegetables you have a reduced risk of developing certain cancers. The exact way in which they protect against cancer is not fully understood. These foods are rich in vitamins and minerals, and also contain chemicals called 'anti-oxidants'. They may protect against damaging chemicals that get into the body. We should all eat at least five portions of fruit and vegetables per day (some experts recommend even more).
Eating too much fatty food possibly increases the risk of developing certain cancers.
The risk of developing certain cancers is increased by: obesity, lack of regular exercise, and drinking a lot of alcohol.
Radiation
Radiation is a carcinogen. For example, exposure to radioactive materials and nuclear 'fallout' can increases the risk of leukaemia and other cancers. Too much sun exposure and sunburn (radiation from UVA and UVB) increase your risk of developing skin cancer.
The larger the dose of radiation, the greater the risk of developing cancer. But note: the risk from small doses such as from a single X-ray test is very small.
Infection
Some viruses are linked to certain cancers. For example, people with persistent infection with the hepatitis B virus or the hepatitis C virus have an increased risk of developing cancer of the liver. But, most viruses and viral infections are not linked to cancer.
Immune system
People with a poor immune system have an increased risk of developing certain cancers. For example, people with AIDS, or people on immunosuppressive therapy.
Your genetic make-up
Some cancers have a strong genetic link. For example, in certain childhood cancers the abnormal gene or genes which may trigger a cell to become abnormal and cancerous are inherited. Other types of cancer may have some genetic factor which is less clear-cut. It may be that in some people their genetic make-up means that they are less resistant to the effect of carcinogens or other factors such as diet.

Let's share your experience about genetic disorders

This is the example from a patient with Marfan Syndrome
Questions and answers from real patients and real doctors.Q. Surgery always scared me. I wanna know that if I take drugs that you said to reduce heart beat, and I also avoid from vigorous exercise as I have read from the leaflet, could it possibly that the great arteries decreased it size or it cannot be reversible.Do I ultimately have to undergo surgery?A. Drug can usually slow down the rate of progressive enlarge of the vessel, but that cannot reverse it to the normal one. Many one can live normally with drug and restrict for some exercise without any surgery. regularly check up by Echo of the heart is mandatory.

Pesronal genome management

There are 160m Americans looking for health information online and somewhere in the realm of 10–30% of those are viewing and creating their own content. But that has made moderate impact on the mainstream press (with Laura Landro being an honorable exception). So it was a little surprising to see both the WSJ and the NY Times feature a related issue in the last week—online genetic screening.

Suddenly the concept of getting your genome tested and laid out online is really hot. 23andme (with its Google connection and Esther Dyson on the board) and Navigenics (with Kleiner Perkins and MDV as blue chip VCs in a $25m round) are the two best known west coast players. 23andme has already found out that Warren and Jimmy Buffet are not related and you can go to their site and sign up for their service for under $1,000. (And learn lots more about it in this Wired article) But they’re not alone. In Boston, Knome is gearing up for something similar and Icelandic company DeCODE genetics, which already has a database with the island’s entire population in it, has also introduced a similar service called DeCodeMe.
And of course there’s The Personal Genome Project. It’s an effort led by George Church and includes 10 people who are putting all their genetic information online. (One is Esther Dyson of course)

Meanwhile, plenty of other companies are doing genetic testing mostly on genealogy grounds. The Genetic Genealogist Blog estimates that some 600,000 tests have been done and they are worth about $300 each. but for an annual market, that’s only $25m. The Genetic Genealogist Blog also has a long list of those genetic companies.
Finally, while there’s all this excitement about doing comprehensive DNA testing, DNADirect has been offering a direct to consumer service for a couple of years which offers the most common tests. You can see their price list here. One estimate which seems in the ball park is that the total market for that testing is $200m.

Trouble shooting for PCR

Hypotheses in order of frequency:
A. Pilot error hypothesis
B. Template dilution hypothesis
C. Temperature errors hypothesis
D. Unique template hypothesis
E. Buffer problems hypothesis
F. Bad dNTPs hypothesis
G. Bad primers hypothesis
H. Bad enzyme hypothesis
I. Bad karma hypothesis

Standard PCR protocol

Materials:

sterile water

10X amplification buffer with 15mM MgCl2

10 mM dNTP

50 μM oligonucleotide primer 1

50 μM oligonucleotide primer 2

5 unit/μl Taq Polymerase

template DNA (1 μg genomic DNA, 0.1-1 ng plasmid DNA) in 10 μl

mineral oil (for thermocyclers without a heated lid
1. Combine the following for each reaction (on ice) in a 0.2 or 0.5 ml tube:
10X PCR buffer 10 μl
Primer 1 1 μl
Primer 2 1 μl
dNTP 2 μl
template DNA and water 85.5 μl
Taq Polymerase 0.5 μl
2. Prepare a control reaction with no template DNA and an additional 10 μl of sterile water.
3. If the thermocycler does not have a heated lid, add 70-100 μl mineral oil (or 2 drops of silicone oil) to each reaction.
4. Place tubes in a thermal cycler preheated to 94 degrees C.
5. Run the following program:
94 degrees C 1 min
55 degrees C 1 min or annealing temperature appropriate for particular primer pair72 degrees C 1 min (if product is <500>500 bp)
for 30 cycles.
Program a final extension at 72 degrees C for 7 min.

DNA protocol (2)

Isolation of DNA from buccal swabs
Materials
50 mM NaOH
1M Tris.Cl, pH 6.5
70% ethanol
CYTo-Pak with Cyto-soft brush (CP-5B; Medical packaging) or Caliber-Cotton-Tipped Apllicator swab (size 6 in; Allegiance Healthcare)
95 degree heating block

Pain in the back, blood in the urine

Have anyone heard about ADPKD (autosomal dominant polycystic kidney disease), one of the most common genetic disorders in the world?
It is the disease of the kidneys, the pea-shape pairs organs, weight about 10 ounces each, in the back of the body on each side of your backbone. They filter your blood and produce urine to remove waste that we produce every day. They also regulates your blood chemicals and acid-base status. The other functions of them is regulation of blood cell production response to body need, produce active vitamin D for helping in calcium absorption to strengthening your bones. If they are severe damage or nearly loss of their function from any causes, so called kidney failure, you will become weakness, loss of energy, shortness of breath, nausea/vomiting, swelling, and even leading to death if kidney replacement such as dialysis, or kidney transplantation is performed. But if they loss only part of their functions, you may not have any symptoms. The most common causes of kidney failure are diabetes and hypertension, which affect adult and elderly and immune-mediated kidney dieases and ADPKD are the more common causes of kidney failure in teenage or young adults.
ADPKD is a kidney diseases characteristics with multiple, various in sizes, growing in both kidneys. The diseases are inherited from parents in a dominant fashion, that means when only one affected father or mother can produced offsprings with ADPKD ( risk is 50%). The defected gene is in every cells of the child since their birth, but usually cysts are gradual develop in their tens or twenties. The patients may come to medical attention by many presentations such as back pain, blood in urine, hypertension, mass in your belly, infection of urinary tract or accidental finding on other health problem unrelated to the disease.
The cysts will grow until they compress normal kidney tissues and this will lead to kidney failure in their 40s-50s. The patients will died if dialysis, or kidney transplantation is not given in time.
The dianosis can be made by perform the imaging study of the kidneys such as ultraasound or CT in patietns suspected to be ADPKD (previous lists of symptoms and family members affected with the same problems) or in family members of ADPKD. Molecular testing can be performed in some families to diagnosis presymptomatic and precyst formation family members.
Treatment of pain, infection and hypertension may alleviate the symptoms and slow down the groth rate of cysts. Due to its serious complications and they are quite common as high as 1 in 1000 birth, this is one of the most active research area to find the drugs to stop progression of diseases.
And we are nearly at that times to treat genetic diseases with simple drugs.
See more information of ADPKD in PKD foundation websites

Timeline of Genetics

Since the early 1900s, there has been an incredible explosion of information in the field of genetics. Biologists have unraveled many mysteries, from the workings of the nucleus to how genetics may be used to understand and treat diseases. This timeline illustrates some major landmarks in the history of genetics.

From Mendel to Molecules:A Brief History of Genetics


1859
Darwin
Charles Darwin publishes The Origin of Species, in which he promotes the theory of natural selection — that members of a population who are better adapted to the environment are more likely to survive and pass on their traits. No theory regarding how traits are passed from generation to generation has been proved true in experiments as of Darwin's time.

1866
Mendel
Gregor Mendel, an Austrian monk, publishes his findings on the laws of inheritance based on experiments, begun in 1857, with pea plants. His studies are ignored until 1900, well after his death in 1884, but his research lays the foundation for studies of inheritance in the twentieth century and beyond. He is called the "father of genetics."


1882
Flemming
German biologist Walter Fleming, by staining cells with dyes, discovers rod-shaped bodies he calls "chromosomes."


1902
Sutton

Garrod

American biologist Walter Sutton demonstrates that chromosomes exist in pairs that are similar in structure. In light of Mendel's theory that genetic "factors" segregate, he concludes that hereditary factors must lie on chromosomes.
Archibald Garrod discovers the first human disease whose inheritance pattern matches one predicted by Mendel's theories by showing that alkaptonuria, a form of arthritis, is inherited as a recessive trait. The discovery is the first to show how the study of inheritance can benefit the practice of medicine.


1906

The term "genetics" is used for the first time.


1909

Danish botanist Wilhelm Johannsen proposes the term "gene" (from the Greek word "genos" which means "birth") to refer to a Mendelian hereditary factor. Johannsen also proposes two terms, genotype and phenotype, to distinguish between one's genetic make-up and one's outward appearance.

1915
Morgan
Thomas Hunt Morgan, an American geneticist, publishes The Mechanism of Mendelian Heredity, in which he presents results from experiments with fruit flies that prove genes are lined up along chromosomes. He also describes the principle of "linkage" — that alleles located relatively close to one another on a chromosome tend to be inherited together. By studying the frequency with which traits are inherited together, Morgan and co-workers create a "genetic map" of fruit fly chromosomes showing the relative locations of the genes responsible for dozens of traits, along with approximate distances between them on the chromosome. This work establishes the basis for gene mapping principles still used today.


1944
Avery
MacLeod
McCarty

Oswald Avery, Colin MacLeod, and Maclyn McCarty report evidence that, at least in bacteria, the molecule that carries genetic information is deoxyribonucleic acid (DNA).


1952
Chase and Hershey
The experiments of Martha Chase and Alfred Hershey provide final proof that DNA is the substance that transmits inherited traits from one generation to the next. Hershey receives a Nobel Prize in 1969 for this work.

1953
Crick

Watson

Francis Crick and James Watson determine that the structure of the DNA molecule is a double helix composed of strings of nucleotides and that two parallel strands formed by sugar and phosphate molecules are joined together by the bonding of specific pairs of nitrogenous bases. The four bases are adenine (A), guanine (G), cytosine (C), and thymine (T). A always pairs with T and C always pairs with G. They share a Nobel Prize for this in 1962.


1955
Tjio
Joe Hin Tjio determines that the number of chromosomes in humans is 46.(For 30 years, the number was believed to be 48.)


1961
Brenner
Jacob
Meselson
Sydney Brenner, Francois Jacob, and Matthew Meselson identify the role of Ribonucleic Acid (RNA). They determine that messenger RNA (mRNA) is the molecule that carries the genetic information from DNA in the nucleus out into the cytoplasm and that the cell ultimately uses mRNA to make specific proteins.

1966
Nirenberg

Khorana

Marshall Nirenberg and H. Gobind Khorana lead teams that crack the genetic code. They demonstrate that each of 20 amino acids is coded by a sequence of three nucleotide bases (each series of three bases is called a codon).


1977
Sanger
Fred Sanger develops the chain termination method for sequencing DNA. Many of today's automated DNA sequencers use the principles underlying Sanger's method.


1978
Botstein
David Botstein and others discover a very useful type of DNA polymorphism, called restriction fragment length polymorphisms (RFLPs). RFLPs are found throughout the genome and are extremely valuable as genetic markers in human genetic studies.


1980
Mullis
Kary Mullis and others at Cetus Corporation invent a technique for making many copies of a specific DNA sequence: the polymerase chain reaction (PCR). PCR is called the most revolutionary technique in molecular biology in the 1980s. Mullis wins a Nobel Prize for this work.


1983
Chromosome 4
The gene for a human genetic disease is mapped to a specific human chromosome. Study of a large family in Venezuela with Huntington disease reveals that the gene responsible for the disease is on the short arm of chromosome 4. The first genetic test for a disease (Huntington's) was developed based on this finding.

1984
Jeffreys
Alec Jeffreys introduces DNA fingerprinting as a method of identification.

1989
Watson
The National Center for Human Genome Research is created. It is headed by James Watson and oversees the $3 billion U.S. effort to map and sequence all human DNA.


1990

The Human Genome Project, an international effort to sequence all of the DNA and map all of the genes in humans, is launched.

1992
Cohen
An international research team, led by Daniel Cohen of the Center for the Study of Human Polymorphisms (CEPH) in Paris, produces a map that includes genetic markers on all 23 human chromosomes. This map is a useful tool for scientists searching for the locations of disease-causing genes.


1993
Roses
Allen Roses, MD, and his colleagues at Duke University announce finding a major susceptibility gene for the late-onset form of Alzheimer Disease.


1994

A high-density genetic map of the human genome, consisting of almost 6,000 markers, is published in Science magazine.
Linkage studies identify genes for a variety of conditions including: bipolar disorder, cerulean cataracts, melanoma, hearing loss, dyslexia, thyroid cancer, sudden infant death syndrome, prostate cancer and dwarfism.



1995
Venter
The first full genome sequence of a living organism other than a virus is completed for the bacterium Hemophilus influenzae by Craig Venter at Celera. A collaboration of scientists reports sequencing of the complete genome of a complex organism, baker's yeast. The achievement marks the complete sequencing of more than 12 million pairs of DNA.


1997
Dolly and Bonnie
Researchers at Scotland's Roslin Institute report cloning a sheep by transferring a cell nucleus from an adult ewe into an embryonic sheep cell. The result is a sheep named "Dolly."(Pictured at left are Dolly and her first lamb, Bonnie, born in 1999)


1998
A human genetic map is produced, showing the chromosomal locations of markers from more than 30,000 human genes.
Herceptin® (trastuzumab) and Herceptest® are approved in the US for the treatment of a subset of women with breast cancer based on the results of a lab test. This is the first time the US Food and Drug Administration required that a diagnostic lab test kit used to predict patient response be made available for use with a drug.


1999
The SNP Consortium is formed by pharmaceutical, information and technology companies and a charitable trust for the purpose of providing public, unrestricted genomic data about single nucleotide polymorphisms (SNPs), the most common form of genetic variation. The resulting SNP map, which is being updated constantly, is used by scientists to find SNP markers for gene mapping and disease studies.


2000
A rough draft of the human genome is completed and published by the Human Genome Project and Celera. The project was planned to last 15 years, but rapid technological advances accelerated the expected completion date. Project goals are to discover all 30,000 to 40,000 human genes (the human genome) and make them accessible for further study and to determine the complete sequence of the 3 billion DNA bases in the human genome.


2001

A private U.S. research company, Advanced Cell Technology (ACT) announces it has cloned human embryos. The company says the intention is not to create cloned human beings but to make lifesaving therapies for a wide range of human diseases. Political and religious leaders around the world condemn the effort.
Researchers announce that genetic screening for a particular gene can help physicians decide which women are best suited to use the drug tamoxifen (while they are still healthy) to help prevent breast cancer. Other researchers announce that they are exploring the use of genetics to predict which patients are most likely to experience serious adverse reactions from a chemotherapy drug.


2003
50 years of DNA
50th anniversary of the discovery of the double-helix structure of DNA by Francis Crick and James Watson, who received the Nobel Prize for their work in 1962. The Human Genome Project publishes the complete human genetic sequence in the journal Nature (24 April 2003), more than two years ahead of schedule

Pharmacogenetics environment 2007

Today at the Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand,there is a work shop on pharmacogenetics environment 2007, held by the research affairs of the Faculty of Medicine, Chulalongkorn University and GlaxoSmithKlien Pharmaceuticals.
The main topics are ethical concerns and regislation or any kinds of regulation in conduct pharmacogenetics(PGx) and pharmacogenomics(PGm) clinical research.
The speakers were Dr. Chanin Limwongse, a clinical geneticist from the Faculty of Medicine, Siriraj hospital, Mahidol University, Dr Rachaneekorn, a genetic scientist from the Faculty of Sciences, Chulalongkorn University, Dr Wasan Chantratit, a virologist, and bioinformaticians, from the faculty of Medicine, Ramathibodi hospital, Mahidol University, and the representatives of GSK (one from UK and one from USA).
Phamacogenetics and pharmacogenomics are the fields involved with study about variation of the DNA, a single point, multiple points or across the whole genome that resulted to different drug response or adverse effect from the drugs. The data will provide the theoretical prediction for the beneficial and side effects of the drugs. The speakers stated that the major problems of today research are not only the back up resources such as granting agencies, equipments, or personnels, but the lack of public and also the investigators themself awareness of the interpretation of the results, the decision making of participations, and ethical issues and regulations of perform such research.
The pharmaceuticals and researchers predicted that pharmacognetics/pharmacogenomics research will become the main stream research practices to improve rate of licensing of the drugs, safe money to run clinical research and safe more patinets in time.

DOWN SYNDROME


DOWN SYNDROME PICTURE

Marfan Syndrome






MARFAN SYNDROME PICTURE

Achondroplasia



ACHONDROPLASIA PICTURE

Achodroplasia

What is achondroplasia?
Achondroplasia is a disorder of bone growth. Although achondroplasia literally means "without cartilage formation," the problem is not in forming cartilage but in converting it to bone, particularly in the long bones of the arms and legs.
All people with achondroplasia have short stature. The average height of an adult male with achondroplasia is 131 centimeters (4 feet, 4 inches), and the average height for adult females is 124 centimeters (4 feet, 1 inch). Characteristic features of achondroplasia include an average-size trunk, short arms and legs with particularly short upper arms and thighs, limited range of motion at the elbows, and an enlarged head (macrocephaly) with a prominent forehead. Fingers are typically short and the ring finger and middle finger may diverge, giving the hand a three-pronged (trident) appearance. People with achondroplasia are generally of normal intelligence.
Health problems commonly associated with achondroplasia include episodes in which breathing slows or stops for short periods (apnea), obesity, and recurrent ear infections. In adulthood, individuals with the condition usually develop a pronounced and permanent sway of the lower back (lordosis) and bowed legs. Older individuals often have back pain, which can cause difficulty with walking.
How common is achondroplasia?
Achondroplasia is the most common type of short-limbed dwarfism. The condition occurs in 1 in 15,000 to 40,000 newborns.
What genes are related to achondroplasia?
Mutations in the FGFR3 gene cause achondroplasia.
The FGFR3 gene provides instructions for making a protein that is involved in the development and maintenance of bone and brain tissue. This protein limits the formation of bone from cartilage (a process called ossification), particularly in the long bones. Two specific mutations in the FGFR3 gene are responsible for almost all cases of achondroplasia. Researchers believe that these mutations cause the protein to be overly active, which interferes with skeletal development and leads to the disturbances in bone growth seen with this disorder.
How do people inherit achondroplasia?
Achondroplasia is inherited in an autosomal dominant pattern, which means one copy of the altered gene in each cell is sufficient to cause the disorder. About 80 percent of people with achondroplasia have average-size parents; these cases result from a new mutation in the FGFR3 gene. In the remaining cases, people with achondroplasia have inherited an altered FGFR3 gene from one or two affected parents. Individuals who inherit two altered copies of this gene typically have very severe problems with bone growth, and are usually stillborn or die shortly after birth from respiratory failure.

Down Syndrome

Introduction
Human cells normally contain 23 pairs of chromosomes. Chromosomes are the parts of body cells that carry inherited information - the characteristics that are passed to you from your mother and father.
A chromosomal disorder means there is a change in the normal number of chromosomes. This can mean that physical and mental development is impaired and can result in learning difficulties and health problems.
Downs Syndrome is the most common chromosomal disorder and one of the most common causes of learning difficulties.
Named after the first person that described it, Dr J L Down, the condition affects one in every 1,000 people. Some are more severely affected than others.
Around 600 babies with Downs Syndrome are born in the UK every year. It occurs in all ethnic groups and affects slightly more boys than girls.
Symptoms
People with Downs Syndrome have lots of different characteristics.
There are thought to be up to 120 features of Downs Syndrome but many children have no more than six or seven of them.
Physical features:

Babies with Downs Syndrome usually weigh less than average at birth and are usually shorter than average as adults.

Children with Downs Syndrome often have a rounded face, with a flat profile (the face looks flat when you view it from the side). The back of the head is slightly flattened (this is called brachycephaly) and the eyes tend to slant upwards.

There are small folds of skin that run vertically between the inner corner of the eye and the bridge of the nose (epicanthic folds) and this can give the impression of crossed eyes (squint). There may be white or yellow speckling around the rim of the iris (coloured part of the eye). These are called Brushfield spots.

Children with Downs Syndrome often have straight, soft hair. As children they may have an extra fold of skin over the back of the neck and as adults, short broad necks.
People with Downs Syndrome often have smaller than average mouths with a bigger than average tongue that may stick out.

The hands may be broad with short fingers; the little finger may only have one joint instead of two and be slightly curved. The feet are often stubby with a wide space between the first and second toes.

Many people with Downs Syndrome have poor muscle tone (hypotonia). This muscular floppiness occurs in the limbs and neck and usually improves with age.

Children with Downs Syndrome learn new skills more slowly than other children and generally develop at a slower rate, meeting their developmental milestones such as walking or talking later. They may progress in stops and starts and may not fully catch up with other children their age. Often, a child with Downs Syndrome will not start to use language until his or her third year and may use some sign language before talking.

With treatment and support, the average life expectancy of someone with Downs Syndrome is about 60 years.

Cytogenetics protocol

Culture and metaphase harvest of peripheral blood
Materials
Heparinized whole blood obtained via Vacutainer (Becton Dickinson) or syringe with preservative-free sodium heparin (25 U/ml)

Complete RPMI/10% FBS medium containing 50 microgram/ml gentamycin sulfate in place of penicillin and streptomycin.

100Xphytohemagglutinin-M (PHA; Life Technologies), reconstituted in sterile deionized water (store at 4 degree celcius)

10 microM methotrexate (optional)

1 mM thymidine (optional)

10 microgram/ml Colcemid (Life Technologies)

75 mM KCl (store < or equal 2 weeks at room temperature)

Fixative 3:1 (v/v) HPLC-grade absolute methanol/glacial acetic acid (prepare fresh)

15 ml sterile disposable conical polypropylene centrifuge tubes (do not use polystyrene)

TB syringe with 21-G needle (VWR Scientific; do not use preattached 25-G needle)

My project (7)

The homeostasis of copper within the body needs to be tightly regulated as deficiency prevents the proper functioning of proteins reliant on copper as a cofactor, whilst excess levels of copper are toxic cells.

Copper is an essential component of many metalloproteins, for example superoxide dismutase (free radical protection), mitochondrial cytochrome-c oxidase (electron transport), tyrosinase (pigmentation) and lysyl oxidase (collagen processing)