sábado, 20 de diciembre de 2014

Gene Test May Help Predict Return of Early Breast Tumor, Study Says: MedlinePlus

Gene Test May Help Predict Return of Early Breast Tumor, Study Says: MedlinePlus

A service of the U.S. National Library of Medicine
From the National Institutes of HealthNational Institutes of Health






Gene Test May Help Predict Return of Early Breast Tumor, Study Says

Idea is to identify women who do and don't need further treatment
Friday, December 12, 2014
HealthDay news image
Related MedlinePlus Pages
FRIDAY, Dec. 12, 2014 (HealthDay News) -- For women who have early breast tumors surgically removed, a new genetic test may help predict the odds of a recurrence, a new study says.
The research, presented Friday at the San Antonio Breast Cancer Symposium, focused on women with ductal carcinoma in situ.
This refers to abnormal cells in the lining of the milk ducts that may or may not progress to cancer that invades the surrounding breast tissue. Because there is no way of foretelling a progression, surgery is usually performed to remove the abnormality.
In the new study, researchers looked at whether a new test that zeroes in on certain genes can help predict which women will have their ductal carcinoma in situ recur after surgery. The goal is to aid doctors and patients in deciding on further treatment.
Right now, surgery is often followed by radiation and, in some cases, the drug tamoxifen, said Dr. Len Lichtenfeld, deputy chief medical officer for the American Cancer Society.
"But we'd all like to have a way to identify women who can avoid further treatment, and those who should have it," said Lichtenfeld, who was not involved in the study.
He explained that doctors already consider a number of factors that affect a woman's need for further treatment. Those include age, the size of the abnormality and its "grade" -- a measure of how aggressive it appears.
"This gene test may add some information to the decision-making process," Lichtenfeld said.
But he stressed that the ultimate value of the test -- known as Oncotype DX -- is not yet known, even though it is already on the market.
"At this juncture," Lichtenfeld said, "the test looks interesting, but it's not widely accepted as a way to guide treatment."
Also, data and conclusions presented at meetings are usually considered preliminary until published in a peer-reviewed medical journal.
The Oncotype test analyzes certain cancer-linked genes to see how "active" they are, then gives the patient's sample a score between 0 and 100.
The test had already been "validated" using tumor samples from patients enrolled in a clinical trial, explained Dr. Eileen Rakovitch, the lead researcher on the new study.
The study team wanted to see how the test performed for women treated in the real world, and not a clinical trial, said Rakovitch, a radiation oncologist at Sunnybrook Health Sciences Center in Toronto, Canada.
So she and her colleagues tested tumor samples from over 1,500 women treated for ductal carcinoma in situ from 1994 to 2003 -- about 700 of whom received surgery only.
The researchers found that among those surgery-only patients, the higher the carcinoma score, the greater the risk of a recurrence over the next decade. For each 50-point increase in the score, the odds of a recurrence doubled.
But the test does not just lump women into lower- or higher-risk groups, Rakovitch noted.
"An individual woman gets information about her personal risk of recurrence over the next 10 years," Rakovitch said.
And that is "much more informative," she added, than relying on traditional factors, such as the tumor size and grade.
Still, the gene test is fairly new to the market, and Lichtenfeld said no one knows yet whether it's making a difference in treatment decisions -- or, most important, women's long-term outlook.
In the United States, diagnoses of ductal carcinoma in situ have shot up because of routine mammography screening, Lichtenfeld noted. The abnormality rarely causes a lump, so it's almost always caught because of mammography imaging.
According to the American Cancer Society, ductal carcinoma in situ accounts for about 20 percent of breast cancer diagnoses -- and nearly all women with it are cured.
The hope, Rakovitch said, is that the Oncotype test will help some women avoid "overtreatment," while others can feel more confident that they need additional treatment after surgery.
Lichtenfeld cautioned that if a doctor does recommend the gene test, women should make sure their insurance covers it. The test costs around $4,000, according to the nonprofit Breastcancer.org.
The study was partly funded by Genomic Health of Redwood City, Calif., which markets the Oncotype test.
SOURCES: Eileen Rakovitch, M.D., associate professor, Sunnybrook Health Sciences Center, Toronto, Ontario, Canada; Len Lichtenfeld, M.D., deputy chief medical officer, American Cancer Society, Atlanta, Ga.; Dec. 12, 2014 presentation, San Antonio Breast Cancer Symposium, San Antonio, Texas
HealthDay
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Adenylosuccinate lyase deficiency - Genetics Home Reference

Adenylosuccinate lyase deficiency - Genetics Home Reference



New on the MedlinePlus Genetic Brain Disorders page:
12/17/2014 11:30 PM EST
Genetics Home Reference: your guide to understanding genetic conditions
Source: National Library of Medicine - NIH


Genetics Home Reference: your guide to understanding genetic conditions



Adenylosuccinate lyase deficiency

Reviewed December 2014

What is adenylosuccinate lyase deficiency?

Adenylosuccinate lyase deficiency is a neurological disorder that causes brain dysfunction (encephalopathy) leading to delayed development of mental and movement abilities (psychomotor delay), autistic behaviors that affect communication and social interaction, and seizures. A characteristic feature that can help with diagnosis of this condition is the presence of chemicals called succinylaminoimidazole carboxamide riboside (SAICAr) and succinyladenosine (S-Ado) in body fluids.
Adenylosuccinate lyase deficiency is classified into three forms based on the severity of the signs and symptoms. The most severe is the neonatal form. Signs and symptoms of this form can be detected at or before birth and can include impaired growth during fetal development and a small head size (microcephaly). Affected newborns have severe encephalopathy, which leads to a lack of movement, difficulty feeding, and life-threatening respiratory problems. Some affected babies develop seizures that do not improve with treatment. Because of the severity of the encephalopathy, infants with this form of the condition generally do not survive more than a few weeks after birth.
Adenylosuccinate lyase deficiency type I (also known as the severe form) is the most common. The signs and symptoms of this form begin in the first months of life. Affected babies have severe psychomotor delay, weak muscle tone (hypotonia), and microcephaly. Many affected infants develop recurrent seizures that are difficult to treat, and some exhibit autistic behaviors, such as repetitive behaviors and a lack of eye contact.
In individuals with adenylosuccinate lyase deficiency type II (also known as the moderate or mild form), development is typically normal for the first few years of life but then slows. Psychomotor delay is considered mild or moderate. Some children with this form of the condition develop seizures and autistic behaviors.

How common is adenylosuccinate lyase deficiency?

Adenylosuccinate lyase deficiency is a rare disorder; fewer than 100 cases have been reported. The condition is most common in the Netherlands and Belgium, but it has been found worldwide.

What genes are related to adenylosuccinate lyase deficiency?

All forms of adenylosuccinate lyase deficiency are caused by mutations in the ADSL gene. This gene provides instructions for making an enzyme called adenylosuccinate lyase, which performs two steps in the process that produces purine nucleotides. These nucleotides are building blocks of DNA, its chemical cousin RNA, and molecules such as ATP that serve as energy sources in the cell. Adenylosuccinate lyase converts a molecule called succinylaminoimidazole carboxamide ribotide (SAICAR) to aminoimidazole carboxamide ribotide (AICAR) and converts succinyladenosine monophosphate (SAMP) to adenosine monophosphate (AMP).
Most of the mutations involved in adenylosuccinate lyase deficiency change single protein building blocks (amino acids) in the adenylosuccinate lyase enzyme, which impairs its function. Reduced function of this enzyme leads to buildup of SAICAR and SAMP, which are converted through a different reaction to succinylaminoimidazole carboxamide riboside (SAICAr) and succinyladenosine (S-Ado). Researchers believe that SAICAr and S-Ado are toxic; damage to brain tissue caused by one or both of these substances likely underlies the neurological problems that occur in adenylosuccinate lyase deficiency.
Studies suggest that the amount of SAICAr relative to S-Ado reflects the severity of adenylosuccinate lyase deficiency. Individuals with more SAICAr than S-Ado have more severe encephalopathy and psychomotor delay.
Read more about the ADSL gene.

How do people inherit adenylosuccinate lyase deficiency?

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

Where can I find information about diagnosis or management of adenylosuccinate lyase deficiency?

These resources address the diagnosis or management of adenylosuccinate lyase deficiency and may include treatment providers.
You might also find information on the diagnosis or management of adenylosuccinate lyase deficiency in Educational resources and Patient support.
General information about the diagnosis and management of genetic conditions is available in the Handbook. Read more about genetic testing, particularly the difference between clinical tests and research tests.
To locate a healthcare provider, see How can I find a genetics professional in my area? in the Handbook.

Where can I find additional information about adenylosuccinate lyase deficiency?

You may find the following resources about adenylosuccinate lyase deficiency helpful. These materials are written for the general public.
You may also be interested in these resources, which are designed for healthcare professionals and researchers.

What other names do people use for adenylosuccinate lyase deficiency?

  • adenylosuccinase deficiency
  • ADSL deficiency
  • succinylpurinemic autism
For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines and How are genetic conditions and genes named? in the Handbook.

What if I still have specific questions about adenylosuccinate lyase deficiency?

Where can I find general information about genetic conditions?

What glossary definitions help with understanding adenylosuccinate lyase deficiency?

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
References (5 links)

The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook.

Neurologists Say Jury Still Out on Medical Marijuana's Use for Brain Disorders: MedlinePlus

Neurologists Say Jury Still Out on Medical Marijuana's Use for Brain Disorders: MedlinePlus

A service of the U.S. National Library of Medicine
From the National Institutes of HealthNational Institutes of Health






Neurologists Say Jury Still Out on Medical Marijuana's Use for Brain Disorders

Easing federal restrictions on pot research might help get answers, doctors say
Wednesday, December 17, 2014
Related MedlinePlus Pages
WEDNESDAY, Dec. 17, 2014 (HealthDay News) -- It's too soon to tell whether medical marijuana can help treat neurological disorders such as epilepsy, multiple sclerosis and Parkinson's disease, the American Academy of Neurology (AAN) said in a new position statement released Wednesday.
Marijuana may be useful in treating some illnesses of the brain and nervous system, but "there is not sufficient evidence to make any definitive conclusions regarding the effectiveness of marijuana-based products for many neurologic conditions," according to the statement.
To help settle the matter, the AAN statement called on the federal government to loosen its current regulations on marijuana research. These regulations likely restrict scientific research into medical pot's effectiveness and safety, the statement suggested.
Medical marijuana might be helpful for people with multiple sclerosis (MS), the AAN noted. It might reduce spasms, decrease pain and control urinary incontinence in people with MS, according to a review of studies the AAN published in April.
But the AAN statement said that the studies conducted so far do not provide enough evidence to support prescribing marijuana for neurological conditions, such as MS.
"They're not as robust as we need them to be," position statement author Dr. Anup Patel, a pediatric neurologist with Nationwide Children's Hospital in Columbus, Ohio, said of the studies conducted so far.
"There are not enough subjects and there's not good enough study design that we can say one way or another that this product would be beneficial and not harmful to our patients," Patel added.
The AAN believes that marijuana should be reclassified so that it's no longer a Schedule I drug. That classification means a drug has no currently accepted medical use and a high potential for abuse, the AAN statement said.
Researchers who want to explore marijuana's medical potential now must fill out reams of extra paperwork, obtain a special license, and adhere to strict storage requirements set forth by the U.S. Drug Enforcement Administration and the U.S. Food and Drug Administration, Patel said.
If federal regulators reclassified marijuana to a less-restrictive status, it would expand researchers' access to the drug. Reclassification would also pave the way for tests that could determine whether or not pot is an effective treatment, the statement said.
"We want this to be answered, like any other medical product, through good science and clinical trials," Patel said. "We in the neurological community are committed to performing those research trials, but it's very, very difficult to do so under current regulations."
Questions that more extensive trials could answer include:
  • Whether THC, the intoxicating chemical in marijuana, would do more harm than good with long-term use. "You're taking a brain that's already not normal, and what effect these products might have on a non-normal brain isn't clear at this point," Patel said. Some studies have shown that long-term marijuana use may cause problems with memory, concentration and decision-making.
  • How the lack of consistency in marijuana doses might affect the drug's usefulness. Levels of THC and other compounds vary widely between different pot harvests. This makes it difficult to determine effectiveness and to prescribe accurately.
  • Whether research conducted on marijuana overseas is similar to treatment in the United States. Many cannabis preparations used in other countries -- sprays, extracts and the like -- are not available in the United States, which means the pot available here might not have the same effect, according to Patel.
  • What effect marijuana might have on the still-developing brains of pediatric patients. Children may be more vulnerable to any toxic effects the drug might have.
The pro-marijuana group NORML disagreed with the AAN's assertion that there isn't enough scientific evidence to prove pot's beneficial effects.
"Empirical data regarding the long-term effects and relative safety of cannabis most certainly is available," said NORML Deputy Director Paul Armentano. "Unlike the case with most pharmaceuticals, for which we have often have sparse data regarding the drugs' long-term effects, humans have been consuming the plant therapeutically and socially for, quite literally, thousands of years -- typically without significant risks to health."
However, NORML agreed that regulations should be loosened to allow for more clinical study of marijuana.
"Unfortunately, the ongoing politicization of cannabis as a Schedule I controlled substance continues to hinder opportunities and funding for the sort of gold-standard clinical research groups like the AAN typically rely upon," Armentano said.
"This situation will only change when cannabis is federally de-scheduled in a manner that fully allows clinical investigators access to the plant," he added.
SOURCES: Anup Patel, M.D., pediatric neurologist, Nationwide Children's Hospital, Columbus, Ohio; Paul Armentano, deputy director, NORML; American Academy of Neurology, position statement, Dec. 17, 2014
HealthDay
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Type A insulin resistance syndrome - Genetics Home Reference

Type A insulin resistance syndrome - Genetics Home Reference



Genetics Home Reference: your guide to understanding genetic conditions

Type A insulin resistance syndrome

Reviewed December 2014

What is type A insulin resistance syndrome?

Type A insulin resistance syndrome is a rare disorder characterized by severe insulin resistance, a condition in which the body's tissues and organs do not respond properly to the hormone insulin. Insulin normally helps regulate blood sugar levels by controlling how much sugar (in the form of glucose) is passed from the bloodstream into cells to be used as energy. In people with type A insulin resistance syndrome, insulin resistance impairs blood sugar regulation and ultimately leads to a condition called diabetes mellitus, in which blood sugar levels can become dangerously high.
Severe insulin resistance also underlies the other signs and symptoms of type A insulin resistance syndrome. In affected females, the major features of the condition become apparent in adolescence. Many affected females do not begin menstruation by age 16 (primary amenorrhea) or their periods may be light and irregular (oligomenorrhea). They develop cysts on the ovaries and excessive body hair growth (hirsutism). Most affected females also develop a skin condition called acanthosis nigricans, in which the skin in body folds and creases becomes thick, dark, and velvety. Unlike most people with insulin resistance, females with type A insulin resistance syndrome are usually not overweight.
The features of type A insulin resistance syndrome are more subtle in affected males. Some males have low blood sugar (hypoglycemia) as the only sign; others may also have acanthosis nigricans. In many cases, males with this condition come to medical attention only when they develop diabetes mellitus in adulthood.
Type A insulin resistance syndrome is one of a group of related conditions described as inherited severe insulin resistance syndromes. These disorders, which also include Donohue syndrome and Rabson-Mendenhall syndrome, are considered part of a spectrum. Type A insulin resistance syndrome represents the mildest end of the spectrum: its features often do not become apparent until puberty or later, and it is generally not life-threatening.

How common is type A insulin resistance syndrome?

Type A insulin resistance syndrome is estimated to affect about 1 in 100,000 people worldwide. Because females have more health problems associated with the condition, it is diagnosed more often in females than in males.

What genes are related to type A insulin resistance syndrome?

Type A insulin resistance syndrome results from mutations in the INSR gene. This gene provides instructions for making a protein called an insulin receptor, which is found in many types of cells. Insulin receptors are embedded in the outer membrane surrounding the cell, where they attach (bind) to insulin circulating in the bloodstream. This binding triggers signaling pathways that influence many cell functions.
Most of the INSR gene mutations that cause type A insulin resistance syndrome lead to the production of a faulty insulin receptor that cannot transmit signals properly. Although insulin is present in the bloodstream, the defective receptors make it less able to exert its effects on cells and tissues. This severe resistance to the effects of insulin impairs blood sugar regulation and leads to diabetes mellitus. In females with type A insulin resistance syndrome, excess insulin in the bloodstream interacts with hormonal factors during adolescence to cause abnormalities of the menstrual cycle, ovarian cysts, and other features of the disorder.
This condition is designated as type A to distinguish it from type B insulin resistance syndrome. Although the two disorders have similar signs and symptoms, type B is not caused by INSR gene mutations; instead, it results from an abnormality of the immune system that blocks insulin receptor function.
Read more about the INSR gene.

How do people inherit type A insulin resistance syndrome?

Type A insulin resistance syndrome can have either an autosomal dominant or, less commonly, an autosomal recessive pattern of inheritance.
In autosomal dominant inheritance, one copy of the altered gene in each cell is sufficient to cause the disorder. In some cases, an affected person inherits the mutation from one affected parent. Other cases result from new mutations in the gene and occur in people with no history of the disorder in their family.
In autosomal recessive inheritance, both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

Where can I find information about diagnosis or management of type A insulin resistance syndrome?

These resources address the diagnosis or management of type A insulin resistance syndrome and may include treatment providers.
You might also find information on the diagnosis or management of type A insulin resistance syndrome in Educational resources and Patient support.
General information about the diagnosis and management of genetic conditions is available in the Handbook. Read more about genetic testing, particularly the difference between clinical tests and research tests.
To locate a healthcare provider, see How can I find a genetics professional in my area? in the Handbook.

Where can I find additional information about type A insulin resistance syndrome?

You may find the following resources about type A insulin resistance syndrome helpful. These materials are written for the general public.
You may also be interested in these resources, which are designed for healthcare professionals and researchers.

What other names do people use for type A insulin resistance syndrome?

  • diabetes mellitus, insulin-resistant, with acanthosis nigricans
  • extreme insulin resistance with acanthosis nigricans, hirsutism and abnormal insulin receptors
  • insulin-resistance syndrome type A
  • insulin resistance syndrome, type A
  • insulin resistance - type A
  • insulin-resistant diabetes mellitus and acanthosis nigricans
  • type A insulin resistance
For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines and How are genetic conditions and genes named? in the Handbook.

What if I still have specific questions about type A insulin resistance syndrome?

Where can I find general information about genetic conditions?

What glossary definitions help with understanding type A insulin resistance syndrome?

References (3 links)

The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook.

Rabson-Mendenhall syndrome - Genetics Home Reference

Rabson-Mendenhall syndrome - Genetics Home Reference



New on the MedlinePlus Diabetes page:
12/17/2014 11:30 PM EST
Genetics Home Reference: your guide to understanding genetic conditions
Source: National Library of Medicine - NIH


Genetics Home Reference: your guide to understanding genetic conditions



Rabson-Mendenhall syndrome

Reviewed December 2014

What is Rabson-Mendenhall syndrome?

Rabson-Mendenhall syndrome is a rare disorder characterized by severe insulin resistance, a condition in which the body's tissues and organs do not respond properly to the hormone insulin. Insulin normally helps regulate blood sugar levels by controlling how much sugar (in the form of glucose) is passed from the bloodstream into cells to be used as energy. In people with Rabson-Mendenhall syndrome, insulin resistance impairs blood sugar regulation and ultimately leads to a condition called diabetes mellitus, in which blood sugar levels can become dangerously high.
Severe insulin resistance in people with Rabson-Mendenhall syndrome affects the development of many parts of the body. Affected individuals are unusually small starting before birth, and infants experience failure to thrive, which means they do not grow and gain weight at the expected rate. Additional features of the condition that become apparent early in life include a lack of fatty tissue under the skin (subcutaneous fat); wasting (atrophy) of muscles; dental abnormalities; excessive body hair growth (hirsutism); multiple cysts on the ovaries in females; and enlargement of the nipples, genitalia, kidneys, heart, and other organs. Most affected individuals also have a skin condition called acanthosis nigricans, in which the skin in body folds and creases becomes thick, dark, and velvety. Distinctive facial features in people with Rabson-Mendenhall syndrome include prominent, widely spaced eyes; a broad nose; and large, low-set ears.
Rabson-Mendenhall syndrome is one of a group of related conditions described as inherited severe insulin resistance syndromes. These disorders, which also include Donohue syndrome and type A insulin resistance syndrome, are considered part of a spectrum. Rabson-Mendenhall syndrome is intermediate in severity between Donohue syndrome (which is fatal before age 2) and type A insulin resistance syndrome (which is often not diagnosed until adolescence). People with Rabson-Mendenhall syndrome develop signs and symptoms early in life and live into their teens or twenties. Death usually results from complications related to diabetes mellitus, such as a toxic buildup of acids called ketones in the body (diabetic ketoacidosis).

How common is Rabson-Mendenhall syndrome?

Rabson-Mendenhall syndrome is estimated to affect less than 1 per million people worldwide. Several dozen cases have been reported in the medical literature.

What genes are related to Rabson-Mendenhall syndrome?

Rabson-Mendenhall syndrome results from mutations in the INSR gene. This gene provides instructions for making a protein called an insulin receptor, which is found in many types of cells. Insulin receptors are embedded in the outer membrane surrounding the cell, where they attach (bind) to insulin circulating in the bloodstream. This binding triggers signaling pathways that influence many cell functions.
The INSR gene mutations that cause Rabson-Mendenhall syndrome reduce the number of insulin receptors that reach the cell membrane or diminish the function of these receptors. Although insulin is present in the bloodstream, without enough functional receptors it is less able to exert its effects on cells and tissues. This severe resistance to the effects of insulin impairs blood sugar regulation and affects many aspects of development in people with Rabson-Mendenhall syndrome.
Read more about the INSR gene.

How do people inherit Rabson-Mendenhall syndrome?

This condition is inherited in an autosomal recessive pattern, which means both copies of the gene in each cell have mutations. The parents of an individual with an autosomal recessive condition each carry one copy of the mutated gene, but they typically do not show signs and symptoms of the condition.

Where can I find information about diagnosis or management of Rabson-Mendenhall syndrome?

These resources address the diagnosis or management of Rabson-Mendenhall syndrome and may include treatment providers.
You might also find information on the diagnosis or management of Rabson-Mendenhall syndrome inEducational resources and Patient support.
General information about the diagnosis and management of genetic conditions is available in the Handbook. Read more about genetic testing, particularly the difference between clinical tests and research tests.
To locate a healthcare provider, see How can I find a genetics professional in my area? in the Handbook.

Where can I find additional information about Rabson-Mendenhall syndrome?

You may find the following resources about Rabson-Mendenhall syndrome helpful. These materials are written for the general public.
You may also be interested in these resources, which are designed for healthcare professionals and researchers.

What other names do people use for Rabson-Mendenhall syndrome?

  • Mendenhall syndrome
  • pineal hyperplasia and diabetes mellitus syndrome
  • pineal hyperplasia, insulin-resistant diabetes mellitus, and somatic abnormalities
  • RMS
For more information about naming genetic conditions, see the Genetics Home Reference Condition Naming Guidelines and How are genetic conditions and genes named? in the Handbook.

What if I still have specific questions about Rabson-Mendenhall syndrome?

Where can I find general information about genetic conditions?

What glossary definitions help with understanding Rabson-Mendenhall syndrome?

You may find definitions for these and many other terms in the Genetics Home Reference Glossary.
References (6 links)

The resources on this site should not be used as a substitute for professional medical care or advice. Users seeking information about a personal genetic disease, syndrome, or condition should consult with a qualified healthcare professional. See How can I find a genetics professional in my area? in the Handbook.