Tag Archives: genetics

Most Genes Matter for Most Traits

What If (Almost) Every Gene Affects (Almost) Everything? – The Atlantic – June 2017 – by ED YONG

If you told a modern geneticist that a complex trait—whether a physical characteristic like height or weight, or the risk of a disease like cancer or schizophrenia—was the work of just 15 genes, they’d probably laugh.

It’s now thought that such traits are the work of thousands of genetic variants, working in concert.

The vast majority of them have only tiny effects, but together, they can dramatically shape our bodies and our health. They’re weak individually, but powerful en masse.  Continue reading

Frequency of CYP2D6 alleles affecting drug metabolism

Prediction of CYP2D6 phenotype from genotype across world populations – Genet Med. 2017 Jan; – free full-text PMC article

Owing to its highly polymorphic nature and major contribution to the metabolism and bioactivation of numerous clinically used drugs, CYP2D6 is one of the most extensively studied drug-metabolizing enzymes and pharmacogenes.

CYP2D6 alleles confer no, decreased, normal, or increased activity and cause a wide range of activity among individuals and between populations.

I’ve added a glossary of genetic terms at the end of this post.  Continue reading

The role of epigenetics in human adaptivity

On epigenetics: we need both Darwin’s and Lamarck’s theories | Aeon Essays – Nov 2016 – by Michael Skinner

This is just an interesting article about the general role of epigenetics in humans. Epigenetics seems to assure a level of randomness and changeability unavailable in our genetic codes, further complicating our efforts to find the “blueprint” for any individual.

By allowing genes to be switched on or off, epigenetics allows the environment, both external and internal to the body, to change the expression of our individual genetic code.

This gives us hope to alter some of how our bodies are genetically programmed to act through subtle changes in our biochemistry, and also assures a level of randomness unavailable in our genetic code. And this further complicates our efforts to find a firm “blueprint” for any individual.  Continue reading

Painful Genetic Diseases

Editor’s Memo: Painful Genetic Diseases – Practical Pain Management – by Forrest Tenant – April 2017

Patients who have painful genetic diseases make up 20% to 30% of my practice.

These patients often report to me that they are misunderstood, that they receive poor pain care, that doctors are afraid of them, and that they have not been able to obtain ongoing chronic pain care.

Part of the problem is that some medical practitioners, including those in emergency rooms and pain clinics, don’t believe that these genetic diseases cause pain.   Continue reading

Chronic pain leads to epigenetic changes

Chronic pain changes our immune systems | Channels – McGill University – By Cynthia Lee – Jan 2016

Many anti-opioid folks believe it’s always better not to prescribe/take opioids because they are so extremely dangerous, while pain is “just a feeling” that a person can “deal with”.

However, they are wrong. Pain is not just a “feeling”.

Leaving pain poorly controlled can lead to changes in how our genes are expressed, especially in the immune system.

Pain is the body’s alarm system, intended to get you moving to either fight or flee. It’s an extreme stressor which initiates a chain of biochemical consequences, including those that turn some of our genes on and off.  Continue reading

Guidelines for the Treatment of Hypothyroidism

Guidelines for the Treatment of Hypothyroidism: Prepared by the American Thyroid Association Task Force on Thyroid Hormone Replacement – 2014 Dec – free full-text PMC article

related to The Fibromyalgia-Thyroid Connection

Background: A number of recent advances in our understanding of thyroid physiology may shed light on why some patients feel unwell while taking levothyroxine monotherapy

The purpose of this task force was to review

  • the goals of levothyroxine therapy,
  • the optimal prescription of conventional levothyroxine therapy,
  • the sources of dissatisfaction with levothyroxine therapy,
  • the evidence on treatment alternatives, and
  • the relevant knowledge gaps.

This document is intended to inform clinical decision-making on thyroid hormone replacement therapy; it is not a replacement for individualized clinical judgment.  Continue reading

Dubious gene test for addiction risk

Dubious gene test for addiction risk exploits loophole and opioid fears

Proove claims its test can predict, with 93 percent accuracy, which patients will become addicted to or misuse prescribed opioid pain pills.

That’s been an irresistible sales pitch for many physicians, who struggle to treat pain patients compassionately but fear adding to the national epidemic of opioid addiction.

The Irvine, Calif., company has recruited 400 doctors, who have used the test to guide their treatment of more than 100,000 patients in the last five years.   Continue reading

Individual variety in response to opioids

Identifying Patients With Higher Methadone Dose RequirementsHelen Fosam, PhDFeb 2017

The variation in response to pharmacological agents between individuals has been recognized for decades.

Unfortunately, the CDC and the other guideline-writing groups are deliberately ignoring this truth. The public is kept ignorant about this criminal negligence of scientific truth (evidence) in the documents created by these groups.

However, the underlying genetic basis that provides a rational explanation for the observation that different individuals can display widely different responses to the same pharmacological agent came to light with the sequencing of the human genome, which allowed the identification of thousands of gene polymorphisms, most often single nucleotide polymorphisms (SNPs)   Continue reading

Ehlers-Danlos receives new classification update

‘Most neglected disorder in modern medicine’ receives major classification update | The Ehlers Danlos Society

This long-awaited review updates the diagnostic criteria for the first time in 20 years, and provides management and care guidelines.

Full paper will be published
at http://ehlers-danlos.com/
on March 15th.

Latest Info 3/16
2017 EDS International Classification

Continue reading

Need for High Opioid Dose Linked to CYP450

Need for High Opioid Dose Linked to CYP450 | Medscape | September 25, 2012 by Nancy A. Melville

The problem of extreme variability in opioid metabolism has been known for years, yet is completely disregarded in creating more and more guidelines for standardized dosages.

Patients with chronic pain who require high doses of opioids to achieve pain relief show exceptionally high rates of defects of the cytochrome P450 (CYP450) enzyme system compared with the general population.

The CYP450 enzyme system is known to play an important role in the metabolism of opioids, and recent advances in genetic testing allow for the easy detection of defects to the enzymes.  Continue reading