Tag Archives: Genetics

Adrenoleukodystrophy

Alternative Names:  Adrenoleukodystrophy; Adrenomyeloneuropathy; Childhood cerebral adrenoleukodystrophy; ALD; Schilder-Addison Complex


Definition:

Adrenoleukodystrophy (ALD),  is a rare, inherited disorder that leads to progressive brain damage, failure of the adrenal glands and eventually death. ALD is a disease in a group of genetic disorders called leukodystrophies. Adrenoleukodystrophy progressively damages the myelin sheath, a complex fatty neural tissue that insulates many nerves of the central and peripheral nervous systems. Without functional myelin, nerves are unable to aid in the conduction of an impulse, which leads to increasing disability.

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Patients with X-linked ALD have defects in the ATP-binding cassette, sub-family D (ALD), member 1 transporter protein, which is encoded by the ABCD1 gene. The ABCD1 (aka ALDP) protein is indirectly involved in the break down of very long-chain fatty acids (VLCFAs) found in the normal diet. Lack of this protein can give rise to an over-accumulation of VLCFAs which can lead to damage to the brain, adrenal gland, and peripheral nervous system.

There are several different types of the disease which can be inherited, but the most common form is an X-linked condition. X-linked ALD primarily affects males, but about one in five women with the disease gene develop some symptoms. Adrenomyeloneuropathy is a less-severe form of ALD, with onset of symptoms occurring in adolescence or adulthood. This form does not include cerebral involvement, and should be included in the differential diagnosis of all males with adrenal insufficiency. Although they share a similar name, X-linked ALD and neonatal adrenoleukodystrophy (NALD), a peroxisome biogenesis disorder, are completely different diseases.

Although this disorder affects the growth and/or development of myelin, leukodystrophies are different from demyelinating disorders such as multiple sclerosis where myelin is formed normally but is lost by immunologic dysfunction or for other reasons.

Causes:

There are several types of ALD, which may be inherited in two different ways, and which can cause different patterns of disease even among people in the same families.

ALD is most commonly inherited as an X-linked condition. This means the abnormal gene is found on the X chromosome.

Because women have two X chromosomes, they have a spare normal gene as well as the abnormal one, so generally only carry the condition (although they may have a mild form of the disease). Men have only one X, so they are affected by the condition.

X-linked ALD may occur in three forms, with onset of symptoms in either childhood or adulthood.

Neonatal ALD is much less common. In this type of ALD the faulty gene isn’t X-linked but is found on one of the other chromosomes. This means both boys and girls can be affected.

Symptoms:
Childhood cerebral type:

•Changes in muscle tone, especially muscle spasms and spasticity
•Crossed eyes (strabismus)
•Decreased understanding of verbal communication (aphasia)
•Deterioration of handwriting
•Difficulty at school
•Difficulty understanding spoken material
•Hearing loss
•Hyperactivity
•Worsening nervous system deterioration
*Coma
*Decreased fine motor control
*Paralysis
•Seizures
•Swallowing difficulties
•Visual impairment or blindness

Adrenomyelopathy:
•Difficulty controlling urination
•Possible worsening muscle weakness or leg stiffness
•Problems with thinking speed and visual memory

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Adrenal gland failure (Addison type):

•Coma
•Decreased appetite
•Increased skin color (pigmentation)
•Loss of weight, muscle mass (wasting)
•Muscle weakness
•Vomiting

Diagnosis:

The diagnosis is established by clinical findings and the detection of serum very long-chain free fatty acid levels. MRI examination reveals white matter abnormalities, and neuro-imaging findings of this disease are somewhat reminiscent of the findings of multiple sclerosis. Genetic testing for the analysis of the defective gene is available in some centers.

Neonatal screening may become available in the future, which may permit early diagnosis and treatment.

Genetics:

X-linkedX-linked ALD (X-ALD) is the most common form of ALD. In X-ALD, the defective ABCD1 gene resides on the X chromosome (Xq28). The incidence of X-ALD is at least 1 in 20,000 male births.[6] The ABCD1 (“ATP-binding cassette, subfamily D, member 1”) gene was discovered in 1993 and codes for a peroxisome membrane protein necessary for the ?-oxidation of VLCFAs.

X-ALD is characterized by excessive accumulation of very long-chain fatty acids (VLCFA), which are fatty acids with chains of 25–30 carbon atoms. The most common is hexacosanoate, with a 26 carbon skeleton. The elevation in (VLCFA) was originally described by Moser et al. in 1981.[8] The precise mechanisms through which high VLCFA concentrations in affected organs cause the disease is still unknown.

Autosomal
Neonatal adrenoleukodystrophy (NALD) is one of three autosomal dominant disorders which belong to the Zellweger spectrum of peroxisome biogenesis disorders (PBD-ZSD).The other two disorders are Zellweger syndrome (ZS), and infantile Refsum disease (IRD). NALD is most frequently caused by mutations in the PEX1, PEX5, PEX10, PEX13, and PEX26 genes.

Treatment:

There’s no cure for ALD, and the nervous system progressively deteriorates, with death usually occurring between one and ten years after the start of symptoms.

Research suggests that a mixture of oleic acid and euric acid, known as Lorenzo’s oil, may delay or reduce symptoms in boys with X-linked ALD by lowering levels of VLCFAs. The most benefit is seen when the treatment is used before symptoms develop, before irreversible damage has occurred.

Bone marrow transplants have also been used with some success in boys in the early stages of X-linked ALD but are not without considerable risk. Newer treatments that may lower brain levels of VLCFA are being tested. Treatment with docosahexanoic acid (DHA) may help young children with neonatal ALD.

Genetic research has identified the transporter proteins and their faulty genes, starting the path towards gene therapy.

Research directions:
Active clinical trials are currently in progress to determine if the proposed treatments are effective:

*Glyceryl Trioleate (Lorenzo’s oil) for Adrenomyelneuropathy.
*Beta Interferon and Thalidomide  This study is closed.
*Combination of Glyceryl Trierucate and Glyceryl Trioleate (Lorenzo’s Oil) in assymptomatic patients.[26]
*Hematopoietic stem cell transplantation.

Prognosis:
Treatment is symptomatic. Progressive neurological degeneration makes the prognosis generally poor. Death occurs within one to ten years of presentation of symptoms. The use of Lorenzo’s Oil, bone marrow transplant, and gene therapy is currently under investigation.

Possible Complications:
•Adrenal crisis
•Vegetative state (long-term coma)

Prevention:
Genetic counseling is recommended for prospective parents with a family history of X-linked adrenoleukodystrophy. Female carriers can be diagnosed 85% of the time using a very-long-chain fatty acid test and a DNA probe study done by specialized laboratories.

Prenatal diagnosis of X-linked adrenoleukodystrophy is also available. It is done by evaluating cells from chorionic villus sampling or amniocentesis.

Disclaimer: This information is not meant to be a substitute for professional medical advise or help. It is always best to consult with a Physician about serious health concerns. This information is in no way intended to diagnose or prescribe remedies.This is purely for educational purpose.

Resources:
http://www.bbc.co.uk/health/physical_health/conditions/adrenoleukodystrophy1.shtml
http://en.wikipedia.org/wiki/Adrenoleukodystrophy
http://www.nlm.nih.gov/medlineplus/ency/article/001182.htm

http://health.bwmc.umms.org/imagepages/17277.htm

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Why Some Diets Work Better for Some People than Others

 

Ever notice some people seem to eat anything they want and never gain a pound, while others seem to gain weight just by looking at fattening foods? You may be seeing things correctly after all. According to research this may have a biological cause. Using fruit flies, researchers have found that genes interacting with diet, rather than diet alone, are the main cause of variation in metabolic traits, such as body weight. This helps explain why some diets work better for some people than ot…hers, and suggests that future diets should be tailored to an individual’s genes rather than to physical appearance.

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“There is no one-size-fits all solution to the diseases of obesity and type-2 diabetes,” said Laura K. Reed, the lead investigator in the work. “Each person has a unique set of genetic and environmental factors contributing to his or her metabolic health, and as a society, we should stop looking for a panacea and start accepting that this is a complex problem that may have a different solution for each individual.”

To make this discovery, the scientists studied 146 different genetic lines of fruit flies that were fed four different diets (nutritionally balanced, low calorie, high sugar, and high fat). Researchers then measured a variety of metabolic traits, including body weight, in each group. Flies in some of the genetic lines were highly sensitive to their diets, as reflected by changes in body weight, while flies of other lines showed no change in weight across diets. The scientists were able to ascertain what portion of the total variation in the metabolic traits was determined by genetics alone, by diet alone, or by the interaction between genotype and diet. Results showed that diet alone made a small contribution to the total variation, while genotype and genotype interactions with diet made very large contributions. This study strongly suggests that some individuals can achieve benefits from altering their dietary habits, while the same changes for others will have virtually no effect.

“The summer beach season often serves as a ‘gut check’ for many in terms of their weight,” said Mark Johnston, Editor-in-Chief of the journal Genetics. “This research explains why the one-size-fits-all approach offered by many diet programs can have dramatically different effects for people who try them.”


Source
: Elements4Health

 

Genes Hold Key to Living Longer Than 100

Exceptional longevity results from favourable genes much more than from a healthy lifestyle and environment, according to the first extensive genetic analysis of people who lived past the age of 100.

Researchers at Boston University have identified 150 genetic variants that, taken together, can predict exceptional longevity with 77 per cent accuracy.

The scientists compared the genomes of 1,055 centenarians with a similar number of control subjects, using DNA-scanning technology. They distilled the differences down to 150 life-extending changes, each affecting one chemical “letter” in the 3bn letters of the human genetic code.

These changes run right across the human genome. A few affect genes associated with age-related diseases, such as the ApoE and Alzheimer’s but many have unknown functions.

“Longevity is an extremely complex genetic trait involving many biological processes,” said Thomas Perls, co-author of the paper and director of the New England Centenarian Study. “We’re a long way from understanding them.”

The research confirmed that there could be no simple “elixir” to extend life, he added.

The scientists were surprised to find that, on the whole, the centenarians did not have fewer genetic variants known to trigger disease than the controls.

“What makes a difference is more the positive enriching effect of genetic variants that protect against disease than the absence of disease-associated variants,” said Dr Perls.

Although the details remain a mystery, what seems to happen as people age is that lifestyle and environment – such as healthy eating, exercising and avoiding smoking and obesity – are important in determining lifespan up to the 80s. After that, genes play an increasingly important role.

DNA rather than lifestyle is almost entirely responsible for generating “super-centenarians” who survive beyond 110. They make up one in 7m people in the industrial world.

Eighty-five per cent of centenarians and 90 per cent of super-centenarians are women. In spite of claims of people living to 140 or 150 in places from the Andes to the Caucasus, Jeanne Calment, who died in France in 1997 at the age of 122, remains the world’s oldest documented person.

Paola Sebastiani, professor of biostatistics at Boston University, said all data from the longevity study would be available without restrictions. “We have no financial interests in it and we are not planning to patent anything here,” she said.

Researchers will put up a web page this month where people can calculate their prospect of longevity. They also expect companies that sell genetic tests to consumers quickly to include a longevity assessment.

Source : Financial Times. July 1st.2010

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Radical New Understanding of Genetic Disease

The theory of the genetic origin of diseases is one of the most firmly upheld doctrines of today’s medicine.
……………….
Medical science claims that cancer is brought on by “mistakes in DNA replication,” causing cells to gradually change from normal to “abnormal” and eventually to “malignant” cells.
Studies in the science of Epigenetics show that genes are by no means ‘set in stone’ but that they can alter themselves in response to a person’s environment.

In short, the DNA and thus the biology of an organism are constantly adjusting themselves to signals from outside the cells, including energetic information arising from thoughts and beliefs.

Diseases such as cancer are not caused by defective genes, as claimed by mainstream geneticists, but rather by non-genetic factors that alter the expression of genes without changing the DNA sequence.

Your brain controls all processes in your body. By comparing brain CT scans with medical records and personal histories, it becomes evident that emotional trauma or “conflict shock” leaves a visible mark in precisely the same area of the brain that controls the disease process.

In fact, diseases are not senseless “disorders” but in reality meaningful biological processes trying to save an organism rather than to destroy it. Your whole organism is engaged in facilitating a conflict resolution. The conflict-related organ responds with functional changes to assist the individual on the physical level during the unexpected distress.

A positive attitude, letting go of anger, feelings of trust and forgiveness can significantly reduce the intensity and duration of a conflict and therefore the “disease”-symptoms.

German New Medicine shifts or rather elevates “prevention” and “healing” to a level where the biology of human beings can be understood as intimately connected with spirituality and a chance for spiritual growth.

An understanding of GNM and the Five Biological Laws has in itself a healing effect as it liberates your mind from fear and inspires trust in the creative wisdom of Mother Nature.
Source: Learning GNM 2009

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Colonoscopy

Definition:
A colonoscopy (koh-luh-NAH-skuh-pee) allows a doctor to look inside the entire large intestine. The procedure enables the physician to see things such as inflamed tissue, abnormal growths, and ulcers. It is most often used to look for early signs of cancer in the colon and rectum. It is also used to look for causes of unexplained changes in bowel habits and to evaluate symptoms like abdominal pain, rectal bleeding, and weight loss.

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What is the colon?
The colon, or large bowel, is the last portion of your digestive tract, or gastrointestinal tract. The colon is a hollow tube that starts at the end of the small intestine and ends at the rectum and anus. The colon is about 5 feet long, and its main function is to store unabsorbed food waste and absorb water and other body fluids before the waste is eliminated as stool.

Preparation for Colonscopy test
You will be given instructions in advance that will explain what you need to do to prepare for your colonoscopy. Your colon must be completely empty for the colonoscopy to be thorough and safe. To prepare for the procedure you will have to follow a liquid diet for 1 to 3 days beforehand. The liquid diet should be clear and not contain food colorings, and may include

*fat-free bouillon or broth
*strained fruit juice
*water
*plain coffee
*plain tea
*diet soda
*gelatin
Thorough cleansing of the bowel is necessary before a colonoscopy. You will likely be asked to take a laxative the night before the procedure. In some cases you may be asked to give yourself an enema. An enema is performed by inserting a bottle with water and sometimes a mild soap in your anus to clean out the bowels. Be sure to inform your doctor of any medical conditions you have or medications you take on a regular basis such as

*aspirin
*arthritis medications
*blood thinners
*diabetes medication
*vitamins that contain iron

The medical staff will also want to know if you have heart disease, lung disease, or any medical condition that may need special attention. You must also arrange for someone to take you home afterward, because you will not be allowed to drive after being sedated.

Procedure
For the colonoscopy, you will lie on your left side on the examining table. You will be given pain medication and a moderate sedative to keep you comfortable and help you relax during the exam. The doctor and a nurse will monitor your vital signs, look for any signs of discomfort, and make adjustments as needed.

The doctor will then insert a long, flexible, lighted tube into your rectum and slowly guide it into your colon. The tube is called a colonoscope (koh-LON-oh-skope). The scope transmits an image of the inside of the colon onto a video screen so the doctor can carefully examine the lining of the colon. The scope bends so the doctor can move it around the curves of your colon.

You may be asked to change positions at times so the doctor can more easily move the scope to better see the different parts of your colon. The scope blows air into your colon and inflates it, which helps give the doctor a better view. Most patients do not remember the procedure afterwards.

The doctor can remove most abnormal growths in your colon, like a polyp, which is a growth in the lining of the bowel. Polyps are removed using tiny tools passed through the scope. Most polyps are not cancerous, but they could turn into cancer. Just looking at a polyp is not enough to tell if it is cancerous. The polyps are sent to a lab for testing. By identifying and removing polyps, a colonoscopy likely prevents most cancers from forming.

The doctor can also remove tissue samples to test in the lab for diseases of the colon (biopsy). In addition, if any bleeding occurs in the colon, the doctor can pass a laser, heater probe, electrical probe, or special medicines through the scope to stop the bleeding. The tissue removal and treatments to stop bleeding usually do not cause pain. In many cases, a colonoscopy allows for accurate diagnosis and treatment of colon abnormalities without the need for a major operation.

During the procedure you may feel mild cramping. You can reduce the cramping by taking several slow, deep breaths. When the doctor has finished, the colonoscope is slowly withdrawn while the lining of your bowel is carefully examined. Bleeding and puncture of the colon are possible but uncommon complications of a colonoscopy.

A colonoscopy usually takes 30 to 60 minutes. The sedative and pain medicine should keep you from feeling much discomfort during the exam. You may feel some cramping or the sensation of having gas after the procedure is completed, but it usually stops within an hour. You will need to remain at the colonoscopy facility for 1 to 2 hours so the sedative can wear off.

Rarely, some people experience severe abdominal pain, fever, bloody bowel movements, dizziness, or weakness afterward. If you have any of these side effects, contact your physician immediately. Read your discharge instructions carefully. Medications such as blood-thinners may need to be stopped for a short time after having your colonoscopy, especially if a biopsy was performed or polyps were removed. Full recovery by the next day is normal and expected and you may return to your regular activities.

For More Information
American College of Gastroenterology
P.O. Box 342260
Bethesda, MD 20827–2260
Phone: 301–263–9000
Fax: 301–263–9025
Email: info@acg.gi.org
Internet: www.acg.gi.org

International Foundation for Functional Gastrointestinal Disorders
P.O. Box 170864
Milwaukee, WI 53217–8076
Phone: 1–888–964–2001 or 414–964–1799
Fax: 414–964–7176
Email: iffgd@iffgd.org
Internet: www.iffgd.org

National Digestive Diseases Information Clearinghouse
2 Information Way
Bethesda, MD 20892–3570
Phone: 1–800–891–5389
TTY: 1–866–569–1162
Fax: 703–738–4929
Email: nddic@info.niddk.nih.gov
Internet: www.digestive.niddk.nih.gov

Sources: http://digestive.niddk.nih.gov/ddiseases/pubs/colonoscopy/index.htm,  http://healthtopics.hcf.com.au/Colonoscopy.aspx

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