diabetestalk.net

What Diabetes Is Genetic

Defining The Genetic Contribution Of Type 2 Diabetes Mellitus

Defining The Genetic Contribution Of Type 2 Diabetes Mellitus

Diabetes mellitus (DM) affects over 150 million people world wide, with a prevalence that varies markedly from population to population.1 Estimates predict that almost 300 million people will suffer from DM by 2025 (fig 1) with the vast majority being cases of diabetes mellitus type 2. Many risk factors have been identified which influence the prevalence (total number of cases as a percentage of the total population) or incidence (total number of new cases per year as a percentage of the total population). Factors of particular importance are a family history of diabetes mellitus, age, overweight, increased abdominal fat, hypertension, lack of physical exercise, and ethnic background. Several biochemical markers have also been identified as risk factors, including fasting hyperinsulinaemia, increased fasting proinsulin, and decreased HDL cholesterol.2 Both diabetes mellitus types 1 and 2 show a familial predisposition, which is a strong indication for the involvement of genes in people's susceptibility to the disease. However, the aetiology underlying types 1 and 2 is different and different genes are likely to be involved in each type of diabetes mellitus. The following discussion focuses on a genetic dissection of type 2 diabetes mellitus. The two most common forms of diabetes mellitus, type 1 and type 2, are both characterised by raised plasma glucose levels. Normal glucose homeostasis depends on the balance between glucose production by the liver and kidneys and glucose uptake by the brain, kidneys, muscles, and adipose tissue. Insulin, the predominant anabolic hormone involved, increases the uptake of glucose from the blood, enhances its conversion to glycogen and triglyceride, and also increases glucose oxidation. Plasma glucose levels are normally kept within a s Continue reading >>

The Genetics Of Diabetes

The Genetics Of Diabetes

Why me? How did I deserve this? Am I to blame? These are questions that many people ask when diagnosed with a serious condition or disease. Unfortunately, there’s no clear-cut answer when it comes to diabetes. Unlike some traits, diabetes doesn’t seem to be inherited in a simple pattern, and there is a lot of misinformation out there about its causes. (Have you ever had to explain that diabetes doesn’t happen because someone ate too much sugar?) It’s apparent, though, that some people are born more likely to develop diabetes than others. We know that type 1 and type 2 diabetes have different causes, but genetics plays an important role in both types. People with diabetes inherit a predisposition to the disease, then something in their environment triggers it. Identical twins are proof that genes alone are not enough, however. Identical twins have identical genes; therefore, they should have the same genetic risk for a disease—right? Not necessarily. Research has found that if one identical twin has type 1 diabetes, the other twin will get the disease about 50 percent of the time. For type 2 diabetes, that risk rises to as much as 4 in 5. In both type 1 and type 2, identical twins have a much higher risk of both developing diabetes than non-identical (fraternal) twins, which further supports the fact that genetics is involved. So what are the causes of type 1 diabetes? Again, we know that genetics is involved. We also know that it’s not just one gene responsible, but many different genes, each of which contributes only a small part of the risk. Scientists have identified a few genes responsible for type 1, but the majority of the genetic risk is still unidentified. Because of the data about identical twins, we know that type 1 diabetes doesn’t arise solely Continue reading >>

Is Diabetes Genetic? Facts About Hereditary Risk

Is Diabetes Genetic? Facts About Hereditary Risk

Diabetes is a complex set of diseases with no single cause. Genetic factors make some people more vulnerable to diabetes, particularly with the right environment. In addition, certain lifestyle factors can cause type 2 diabetes in individuals with no known family history. This complex interaction between genes, lifestyle, and environment points to the importance of taking steps to minimize individual diabetes risk. Is type 1 diabetes hereditary? Type 1 diabetes is an autoimmune disease, which means that it causes the body's immune system to attack healthy cells. It is often called juvenile diabetes because most people are diagnosed in childhood, and the condition then lasts their lifetime. Doctors used to think type 1 diabetes was wholly genetic. Newer studies have shown, however, that children develop type 1 diabetes 3 percent of the time if their mother has the condition, 5 percent of the time if their father has it, or 8 percent if a sibling has type 1 diabetes. Consequently, researchers now believe that something in the environment has to trigger type 1 diabetes. Some risk factors include: Cold weather. People develop type 1 diabetes in winter more frequently than summer. It is also more common in places with cool climates. Viruses. Researchers think some viruses might activate type 1 diabetes in people who are otherwise vulnerable. Measles, mumps, coxsackie B virus, and rotavirus have been linked to type 1 diabetes. Research suggests that people who develop type 1 diabetes may have autoimmune antibodies in their blood for many years before showing symptoms. As a result, the disease may develop over time, or something may have to activate the autoimmune antibodies for symptoms to appear. Is type 2 diabetes hereditary? Type 2 diabetes is the more common form of the d Continue reading >>

Is Diabetes Genetic?

Is Diabetes Genetic?

Diabetes is a complex disease. Several factors must come together for a person to develop Type 2 Diabetes. While genetics may influence whether you’ll get this disease or not, other factors like environmental risk factors and a sedentary lifestyle also play a huge role. So, is type 2 diabetes genetic? And if not, which type of diabetes is genetic? Those are the questions we are faced with today. And unfortunately, the answer is not that simple. Yes, genetics can play a role in increasing the risk for both Diabetes Type 1 as well as Diabetes Type 2, but genes alone will not determine whether you will develop diabetes or not. Will You Get Diabetes If It Runs In Your Family? If you’ve just been diagnosed with diabetes, chances are that you’re not the first person in your family who has diabetes. The details of whether diabetes can be inherited, and how this occurs, are not clear yet. About 10% of patients diagnosed with insulin-dependent Type 1 diabetes have a first degree relative with this type of diabetes. By first degree relative, we mean father, mother, sibling, twin and child. However, when it comes to the more common type of diabetes, which is Diabetes Type 2, it has a tendency to occur in families, but this is also not very strong and not predictable. A Swedish study on Metabolic Consequences of a Family History of Non-Insulin Dependent Diabetes Mellitus concluded that abdominal obesity, insulin resistance, and decreased resting metabolic rate are characteristic features of first-degree relatives of patients with non-insulin dependent diabetes mellitus (in other words, Diabetes Type 2). And that the decrease in resting metabolic rate is partially related to the degree of abdominal obesity. Many doctors with clinical practice treating diabetes believe that thi Continue reading >>

Genetics Of Type 1a

Genetics Of Type 1a

Type 1 diabetes is a complex genetic disorder. There are now at least 20 insulin-dependent genes associated with the development of diabetes. Type 1 diabetes is a complex genetic disorder. It occurs more frequently in families in which there are other relatives with type 1 diabetes and other autoimmune conditions. Children have a 5% to 6% chance of developing diabetes if their father has type 1 diabetes, and a 3% to 4% chance if their mother has type 1 diabetes. It is thought that some of the mother’s chromosomal material, or DNA, gets inactivated when passed on to the child, thereby accounting for the difference in the children’s diabetes risk. If a sibling has type 1 diabetes, the risk is 5-6%; however, if the sibling has identical MHC (Major Histocompatibility Complex) haplotypes, the risk increases. When one identical twin has diabetes, the risk of the other twin developing diabetes traditionally has been thought to be about 40%. Recent research suggests that the number may be much higher. A number of genes have been identified that are associated with the development of diabetes. The chromosomal locations of these “diabetes genes” are called inherited susceptibility loci. There are now at least 20 insulin-dependent diabetes mellitus (IDDM) susceptibility loci. The most important are: IDDM 1 (the major histocompatibility complex on chromosome 6) IDDM 2 (the insulin gene locus on chromosome 11) PTPN 22 (the protein tyrosine phosphatase gene) with a mutation at LYP (the lymphocyte-specific phosphatase gene) on chromosome 1 associated with susceptibility to multiple autoimmune disorders IDDM 1 It is estimated that about 40-50% of the risk for type 1 diabetes is associated with the MHC complex or IDDM 1 loci. The MHC genes most associated with diabetes in white Continue reading >>

Diabetes Mellitus Type 1 Inheritance

Diabetes Mellitus Type 1 Inheritance

Type 1 diabetes is an inherited condition and individuals with a first degree relative who has the condition are at an increased risk of developing the condition. Details regarding the risk of inheriting type 1 diabetes are given below: In men with type 1 diabetes, the risk of their child also developing the condition is one in 17. In women with type 1 diabetes who have their baby before the age of 25, the risk of the child developing the condition is one in 25. If she has her baby after the age of 25, the risk falls to 1 in 100. If both parents have type 1 diabetes, the risk of the condition developing in offspring varies between 1 in 4 and 1 in 10. The risks are somewhat increased if one of the parents developed type 1 diabetes before the age of 11. Around 1 in 7 people with type 1 diabetes suffer from a condition called type 2 polyglandular autoimmune syndrome and these individuals have parathyroid and adrenal gland disorders in addition to type 1 diabetes. If one of the parents has type 2 polyglandular autoimmune syndrome, the risk that the child will inherit the condition, including type 1 diabetes, is 50%. Genes associated with type 1 diabetes Some genes have repeatedly been identified in people with type 1 diabetes. Among white individuals, examples of such genes include the HLA-DR3 or HLA-DR4 genes. Carrying these genes raises the risk that offspring will inherit type 1 diabetes. Children born with the HLADR3/4-DQ8 genotype make up nearly 50% of all children who develop type 1 diabetes before they are 5 years of age. Some studies on other ethnic groups have shown that similar risks are associated with the HLA-DR7 genotype among African Americans and with the HLA-DR9 gene among Japanese individuals. Genetic studies have also located HLA class II genes at 6p21 and Continue reading >>

What Is Type 2 Diabetes?

What Is Type 2 Diabetes?

Diabetes is a disease that's characterized by high blood sugar, which doctors refer to as hyperglycemia. In type 2 diabetes, the two main contributors to high blood sugar are insulin resistance and a drop in your body's production of insulin. These two factors are what makes type 2 diabetes different from type 1 diabetes, gestational diabetes, and other types of diabetes. What Is Insulin Resistance? Insulin — the hormone that allows your body to regulate sugar in the blood — is made in your pancreas. Insulin resistance is a state in which the body’s cells do not use insulin efficiently. As a result, it takes more insulin than normal to transport glucose (the main type of sugar found in the bloodstream) into cells, where it can be used for fuel or stored for later use. Insulin resistance develops over time, and as the body becomes more and more insulin resistant, the pancreas responds by releasing more and more insulin. This higher-than-normal level of insulin in the bloodstream is called hyperinsulinemia. For a while, the pancreas may be able to keep up with the body’s increased need for insulin, and blood sugar levels may stay within the normal range — about 70 to 100 mg/dl before meals and lower than 140 mg/dl after meals. Eventually, however, the pancreas can no longer keep up, and blood sugar levels begin to rise. What Causes Type 2 Diabetes? It's not known for certain why some people develop type 2 diabetes and some do not. There are several factors, however, that can increase a person's risk of developing type 2 diabetes: Obesity Being obese or overweight puts you at significant risk for developing type 2 diabetes. Four out of five people with type 2 diabetes are overweight or obese. Prediabetes Prediabetes is a condition in which your blood sugar levels Continue reading >>

What Is The Specific Evidence That Diabetes Type Ii Is Genetic?

What Is The Specific Evidence That Diabetes Type Ii Is Genetic?

As Adriana Heguy noted in Adriana Heguy's answer to What is the specific evidence that diabetes type II is genetic? NIH has released Genetic Factors in Type 2 Diabetes which reads in part In rare forms of diabetes, mutations of one gene can result in disease. However, in type 2 diabetes, many genes are thought to be involved. "Diabetes genes" may show only a subtle variation in the gene sequence, and these variations may be extremely common. The difficulty lies in linking such common gene variations, known as single nucleotide polymorphisms (SNPs), with an increased risk of developing diabetes. This means that while there is a relationship between some genes and Type 2 Diabetes, in the strict sense that your question is phrased, the condition is not heritable in the same sense as eye color, blood type, sickle cell trait, etc. There is no definitive answer to your question in its strictest sense. [The remainder of this answer was first posted as part of the comment thread to Adriana Heguy's answer to What is the specific evidence that diabetes type II is genetic? which included references to 23AndMe.] My understanding is that much of the genetics research to date has been in the initial stages of the discovery phase. "Initial" because researchers are still building databases of individual's genomes. If you look at papers dealing with this type of research on the NIH PubMed site (Home - PubMed - NCBI) many papers are based on studying genomes of just a few dozen individuals. Papers may argue this is enough to establish with some statistical confidence that a connection does or does not exist between a particular genetic anomaly and a condition, but not enough to say how strong that correlation is. In other words, enough to say that genetic anomaly X probably has something Continue reading >>

Type 1 Diabetes

Type 1 Diabetes

Type 1 diabetes is a disorder characterized by abnormally high blood sugar levels. In this form of diabetes, specialized cells in the pancreas called beta cells stop producing insulin. Insulin controls how much glucose (a type of sugar) is passed from the blood into cells for conversion to energy. Lack of insulin results in the inability to use glucose for energy or to control the amount of sugar in the blood. Type 1 diabetes can occur at any age; however, it usually develops by early adulthood, most often starting in adolescence. The first signs and symptoms of the disorder are caused by high blood sugar and may include frequent urination (polyuria), excessive thirst (polydipsia), fatigue, blurred vision, tingling or loss of feeling in the hands and feet, and weight loss. These symptoms may recur during the course of the disorder if blood sugar is not well controlled by insulin replacement therapy. Improper control can also cause blood sugar levels to become too low (hypoglycemia). This may occur when the body's needs change, such as during exercise or if eating is delayed. Hypoglycemia can cause headache, dizziness, hunger, shaking, sweating, weakness, and agitation. Uncontrolled type 1 diabetes can lead to a life-threatening complication called diabetic ketoacidosis. Without insulin, cells cannot take in glucose. A lack of glucose in cells prompts the liver to try to compensate by releasing more glucose into the blood, and blood sugar can become extremely high. The cells, unable to use the glucose in the blood for energy, respond by using fats instead. Breaking down fats to obtain energy produces waste products called ketones, which can build up to toxic levels in people with type 1 diabetes, resulting in diabetic ketoacidosis. Affected individuals may begin breathin Continue reading >>

Genetic Types Of Diabetes Including Maturity-onset Diabetes Of The Young (mody)

Genetic Types Of Diabetes Including Maturity-onset Diabetes Of The Young (mody)

Diabetesgenes.org aims to provide information for patients and professionals on research and clinical care in genetic types of diabetes.Please select the tabs on the left for more information on Making a Diagnosis of Monogenic Diabetes, Maturity Onset Diabetes of the Young (MODY), Neonatal Diabetes, Renal Cysts and Diabetes, Hyperinsulinism or choose Exeter Research if you would like information about our current projects or individual researchers.This website is run by the Diabetes Research department and the Centre for Molecular Genetics at the University of Exeter Medical School and Royal Devon and Exeter Hospital, Exeter, UK. *New for 2018! If you would be interested in attending a 2 day course on monogenic diabetes please register your interest with Becky Dobbs: [email protected] (01392 408182). For more information please click here Course duration: 4 weeksCourse frequency: ~6 times yearlyThe University of Exeter diabetes research teams and the Molecular Genetics team have collaborated to recently develop a MOOC (Massively-Open Online Course) with FutureLearn.com. This free online course introduces the topic of genomics and illustrates the clinical application of current knowledge in genomics, with particular focus on monogenic diabetes.This course is designed for anyone who wants to learn about how the genomic era is changing medical science, including healthcare professionals, science undergraduates and non-specialists who just want to learn more about genomic medicine. Diabetes Diagnostics App The Diabetes Diagnostics app is now available on the App Stores for Apple & Android devices, combining the MODY clinical prediction calculator, information from national and international diabetes guidelines, and expert opinion from world leaders in monogenic diabete Continue reading >>

Diabetes Genetics: How Is Diabetes Inherited?

Diabetes Genetics: How Is Diabetes Inherited?

An estimated 2.5 to 3 million Americans have type 1 diabetes. My father was one of them. Diagnosed around age 10, he spent most of his life injecting insulin into his arms, stomach and legs. Eventually, his eye sight and heart could no longer function properly, and he passed away when I was in high school. Around this time, I was introduced to the subject of genetics. I thought back to all those check-ups at the Joslin clinic (now Joslin Diabetes Center) and realized that genetics was the reason everyone watched me and my sister so closely. Genetics was the reason my family was so scared when I starting gaining too much weight in middle school and freaked out every time my foot fell asleep or I was thirsty. Genetics. The loss of my father and timely introduction to genetics drove my decision to become a genetic counselor. Part of a genetic counselors job is to assess disease risk using what we know about family history, the genes and mutations involved, and sometimes, genetic and non-genetic testing results. We then use that information to help individuals and families make more informed decisions about their health. The Genetics of Diabetes Type 1 and type 2 diabetes are both considered to have multifactorial inheritance — meaning that many factors contribute to the development of these conditions. While the manner of inheritance may be the same for these two conditions, the genetic, lifestyle and environmental risk factors are different. A number of genes associated with immune system function have been linked to type 1 diabetes susceptibility. Many Caucasians with diabetes have specific genetic variations (called 3 and/or 4) in the HLA-DR gene. We also know that different variations, HLA-DR7 and HLA-DR9, play important roles in African-Americans and the Japanese, r Continue reading >>

What Causes Type 2 — Genes Or Food?

What Causes Type 2 — Genes Or Food?

There’s a major split in the Type 2 diabetes world. Some believe Type 2 is all about diet (and maybe exercise.) Others say it’s mostly a genetic illness and that diet doesn’t make much difference. Who’s right? This disagreement came to the forefront in the controversy over TV chef Paula Deen. When Deen told the world she had Type 2 diabetes, some people blamed the high-sugar and high-fat food she cooks on her shows. (One signature dish is deep-fried cheesecake.) But Deen denied her diet had much to do with it. She pointed out that many people eat like her and don’t get diabetes. She said her genes were at fault, even though no one else in her family has diabetes. Bloggers jumped in; some to attack Deen, some to defend her. On Diabetes Self-Management, Jan Chait wrote, “Psst! Food does NOT give you diabetes!” Some doctors agreed. Dr. Terry Simpson wrote, “It is more a matter of genetics than anything else. For those who are unlucky enough to have the genetic code that predisposes them to diabetes, the odds are they will become its victim… Even the most “in shape” individual, who eats “right” who has the genetics for diabetes can no more avoid that than you can avoid a car accident if someone misses a stop sign because they are texting.” I beg to differ. Blaming genes without referencing diet makes no sense at all. There has been an increase in diabetes worldwide of 100% to 400% (depending on location) in the last 20 years. Genes don’t change that fast. The environment has changed. People are more sedentary and more stressed now. But the number one change has been the mass consumption of sugars and refined carbs. Dr. Robert Lustig at University of California San Francisco blames sugars for most of the diabetes increase. Our bodies just weren Continue reading >>

Genetics & Diabetes : What's Your Risk?

Genetics & Diabetes : What's Your Risk?

A school nurse anxiously wants to know if there is a reason why several children from her small grade school have been diagnosed with type 1 (juvenile onset) diabetes. Is it an epidemic? Will there be more cases? Is a recent chicken pox outbreak to blame? A man in his 50s develops type 2 diabetes. His mother developed diabetes in her 60s. Should this man's brother and sister be concerned, too? What about his children's chances of developing diabetes? A married couple wants to have children, but they are concerned because the husband has type 1 diabetes. They wonder what the risk is that their child would have diabetes. A couple has three young children. One of the children develops type 1 diabetes. There's no history of diabetes anywhere in either parent's families. Is this just a fluke? What are the chances the other children will develop diabetes? Chances are if you or a loved one have diabetes, you may wonder if you inherited it from a family member or you may be concerned that you will pass the disease on to your children. Researchers at Joslin Diabetes Center report that, while much has been learned about what genetic factors make one more susceptible to developing diabetes than another, many questions remain to be answered. While some people are more likely to get diabetes than others, and in some ways type 2 (adult onset diabetes) is simpler to track than type 1 (juvenile onset) diabetes, the pattern is not always clear. For more than 20 years researchers in the Epidemiology and Genetics Section at Joslin in Boston (Section Head Andrzej S. Krolewski, M.D., Ph.D., Senior Investigator James H. Warram, M.D., Sc.D., and colleagues) have been studying diabetes incidence and hereditary factors. They are continuing a scientific journey begun by Elliott P. Joslin, M.D., Continue reading >>

Genetics Of Type 2 Diabetes

Genetics Of Type 2 Diabetes

Abstract BACKGROUND: Type 2 diabetes (T2D) is a complex disorder that is affected by multiple genetic and environmental factors. Extensive efforts have been made to identify the disease-affecting genes to better understand the disease pathogenesis, find new targets for clinical therapy, and allow prediction of disease. CONTENT: Our knowledge about the genes involved in disease pathogenesis has increased substantially in recent years, thanks to genomewide association studies and international collaborations joining efforts to collect the huge numbers of individuals needed to study complex diseases on a population level. We have summarized what we have learned so far about the genes that affect T2D risk and their functions. Although more than 40 loci associated with T2D or glycemic traits have been reported and reproduced, only a minor part of the genetic component of the disease has been explained, and the causative variants and affected genes are unknown for many of the loci. SUMMARY: Great advances have recently occurred in our understanding of the genetics of T2D, but much remains to be learned about the disease etiology. The genetics of T2D has so far been driven by technology, and we now hope that next-generation sequencing will provide important information on rare variants with stronger effects. Even when variants are known, however, great effort will be required to discover how they affect disease risk. Type 2 diabetes (T2D)2 is a common complex disorder with an increasing prevalence worldwide. In 2010 it was estimated that 6.6% of the world population of individuals 20–79 years old have diabetes, and that T2D constitutes approximately 90% of diabetes cases (1). This number is expected to increase epidemically as a consequence of an aging population and changes Continue reading >>

Diabetes In The Family: Is It Inherited?

Diabetes In The Family: Is It Inherited?

I’m asking this on behalf of a friend whose grandfather and father have diabetes. Is it more likely that my friend will get it too? Is diabetes fatal? Diabetes occurs in two forms; type 1 diabetes (insulin-dependent diabetes), which occurs in young people and is the more severe form, requiring insulin injections type 2 diabetes (non-insulin dependent diabetes), which is milder and occurs in older people and is usually controlled with diet and tablets. The details of whether diabetes can be inherited, and how this occurs, are not clear. About 10 per cent of people getting the more severe Type 1 diabetes have a close relative with this type of diabetes. That is not the same as saying that 10 per cent of people with affected relatives will get diabetes, but there is an unpredictable association. Type 2 diabetes also has a tendency to occur in families, but this is also not very strong and not predictable. In your friend’s case, if grandfather and father are affected, they probably have the milder Type 2 form of diabetes, so your friend has little risk of developing diabetes at a young age. It may be there is an increased risk of him developing diabetes in later life, but it would be the milder Type 2 form. I am a little confused that you say, ‘he takes pills and does a blood sugar test’. If you are referring to your friend then this probably means he has the mild form of diabetes already, and is probably an older person. You ask if you can get very ill with diabetes and die. Diabetes is a serious condition, but these days if patients follow their diet and take their pills or insulin treatment regularly, and keep their blood sugar within certain limits, they rarely get seriously ill and can live a long and active life. That is not to say there are no dangers with di Continue reading >>

More in diabetes