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| {{Infobox_Disease | | | {{Infobox_Disease | |
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| {{Maturity onset diabetes of the young}} | | {{Maturity onset diabetes of the young}} |
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| {{CMG}} | | {{CMG}} |
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| {{SK}} MODY; | | {{SK}} MODY; |
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| ==Signs, symptoms and differential diagnosis== | | == [[Maturity onset diabetes of the young overview|Overview]] == |
| There are two general types of clinical presentation. Some forms of MODY produce significant [[hyperglycemia]] and the typical signs and symptoms of diabetes: increased thirst and urination (polydipsia and polyuria). In contrast, however, many people with MODY have no signs or symptoms and are diagnosed by either accident, when a high glucose is discovered during testing for other reasons, or screening of relatives of a person discovered to have diabetes. Discovery of mild hyperglycemia during a routine [[glucose tolerance test]] for [[pregnancy]] is particularly characteristic.
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| | == [[Maturity onset diabetes of the young historical perspective|Historical Perspective]] == |
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| | == [[Maturity onset diabetes of the young classification|Classification]] == |
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| MODY cases may make up as many as 5% of presumed type 1 and type 2 diabetes cases in a large clinic population. While the goals of diabetes management are the same no matter what type, there are two primary advantages of confirming a diagnosis of MODY. Firstly, insulin may not be necessary and it may be possible to switch a person from insulin injections to oral agents without loss of [[Diabetes management#Glycemic control|glycemic control]]. Secondly, it may prompt screening of relatives and so help identify other cases in family members.
| | == [[Maturity onset diabetes of the young pathophysiology|Pathophysiology]] == |
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| As it occurs infrequently, many cases of MODY are initially assumed to be more common forms of diabetes: type 1 if the patient is young and not overweight, type 2 if the patient is overweight, or [[gestational diabetes]] if the patient is pregnant. Standard diabetes treatments (insulin for type 1 and gestational diabetes, and oral hypoglycemic agents for type 2) are often initiated before the doctor suspects a more unusual form of diabetes. In some forms of MODY, standard treatment is appropriate, though exceptions occur. For example, in MODY2, oral agents are relatively ineffective and insulin is unnecessary, while in MODY1 and MODY3, insulin may be more effective than drugs to increase insulin sensitivity. [[Sulfonylurea]]s are effective in the K<sub>ATP</sub> channel forms of neonatal-onset diabetes.
| | == [[Maturity onset diabetes of the young causes|Causes]] == |
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| The following characteristics suggest the possibility of a diagnosis of MODY in hyperglycemic and diabetic patients:
| | == [[Maturity onset diabetes of the young differential diagnosis|Differentiating Maturity onset diabetes of the young from other Diseases]] == |
| * Mild to moderate hyperglycemia (typically 130-250 mg/dl, or 7-14 mM) discovered before 30 years of age.
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| * A first degree relative with a similar degree of diabetes.
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| * Absence of positive antibodies or other [[autoimmunity]] (e.g., [[thyroiditis]]) in patient and family.
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| * Persistence of a low insulin requirement (e.g., less than 0.5 u/kg/day) past the usual "honeymoon" period.
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| * Absence of obesity (though obese people can get MODY), or other problems associated with type 2 diabetes or [[metabolic syndrome]] (e.g. [[hypertension]], [[hyperlipidemia]], [[polycystic ovary syndrome]]).
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| * Cystic [[kidney]] disease in patient or close relatives.
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| *Non-transient neonatal diabetes, or apparent [[type 1 diabetes mellitus|type 1 diabetes]] with onset before 6 months of age.
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| The diagnosis of MODY is confirmed by specific [[gene]] testing, now available through several commercial [http://www.genetests.org/servlet/access?id=8888892&key=Ocb32xYXEzdQY&fcn=y&fw=iHXb&filename=/ laboratories].
| | == [[Maturity onset diabetes of the young epidemiology and demographics|Epidemiology and Demographics]] == |
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| ==Management== | | == [[Maturity onset diabetes of the young risk factors|Risk Factors]] == |
| Unfortunately, chronic hyperglycemia of any cause can eventually cause blood vessel damage and the microvascular complications of diabetes. The principal treatment goals for people with MODY — keeping the blood sugars as close to normal as possible ("good [[Diabetes management#Glycemic control|glycemic control]]"), while minimizing other vascular risk factors — are the same for all known forms of diabetes.
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| Tools available for management are also those available for all forms of diabetes: blood testing, changes in [[diet (nutrition)|diet]], physical [[exercise]], oral hypoglycemic agents, and insulin injections. In many cases these goals can be achieved more easily with MODY than with ordinary types 1 and 2 diabetes. Some people with MODY may require insulin injections to achieve the same [[Diabetes management#Glycemic control|glycemic control]] that another person may attain with careful eating or an oral medication.
| | == [[Maturity onset diabetes of the young screening|Screening]] == |
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| When oral hypoglycemic agents are used in MODY, the sulfonylureas remain the oral medication of first resort. Patients with MODY less often suffer from obesity and [[insulin resistance]] than those with ordinary type 2 diabetes (for whom insulin sensitizers like [[metformin]] or the [[thiazolidinedione]]s are often preferred over the sulfonylureas).
| | == [[Maturity onset diabetes of the young natural history, complications and prognosis|Natural History, Complications and Prognosis]] == |
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| ==Related homozygous disorders== | | == Diagnosis == |
| By definition, the forms of MODY are autosomal dominant, requiring only one abnormal gene to produce the disease; the severity of the disease is moderated by the presence of a second, normal allele which presumably functions normally. However, a small number of people carrying two abnormal alleles have been identified. Unsurprisingly, combined (homozygous) defects of these genes are both much rarer and much more severe in their effects.
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| *Homozygous glucokinase deficiency causes severe congenital insulin deficiency resulting in persistent neonatal diabetes mellitus. About 6 cases have been reported worldwide. All have required insulin treatment from shortly after birth. The condition does not seem to improve with age.
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| *Homozygous IPF1 results in failure of the pancreas to form. Congenital absence of the pancreas, termed pancreatic agenesis, involves deficiency of both endocrine and exocrine functions of the pancreas.
| | [[Maturity onset diabetes of the young history and symptoms|History and Symptoms]] | [[Maturity onset diabetes of the young physical examination|Physical Examination]] | [[Maturity onset diabetes of the young laboratory tests|Laboratory Findings]] | [[Maturity onset diabetes of the young CT|CT]] | [[Maturity onset diabetes of the young MRI|MRI]] | [[Maturity onset diabetes of the young echocardiography or ultrasound|Echocardiography or Ultrasound]] | [[Maturity onset diabetes of the young other imaging findings|Other Imaging Findings]] | [[Maturity onset diabetes of the young other diagnostic studies|Other Diagnostic Studies]] |
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| Homozygous HNF4α, HNF1α, HNF1β, and NeuroD1 mutations have not yet been described. Those mutations for which a homozygous form has not been described may be extremely rare, or may result in clinical problems not yet recognized as connected to the monogenic disorder, or may be lethal for a fetus and not result in a viable child.
| | == Treatment == |
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| ==References==
| | [[Maturity onset diabetes of the young medical therapy|Medical Therapy]] | [[Maturity onset diabetes of the young surgery|Surgery]] | [[Maturity onset diabetes of the young primary prevention|Primary Prevention]] | [[Maturity onset diabetes of the young secondary prevention|Secondary Prevention]] | [[Maturity onset diabetes of the young cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Maturity onset diabetes of the young future or investigational therapies|Future or Investigational Therapies]] |
| {{reflist|2}}
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| ==Further reading== | | == Case Studies == |
| * {{cite journal |author=Fajans SS |title=Scope and heterogeneous nature of MODY |journal=Diabetes Care |volume=13 |issue=1 |pages=49–64 |year=1990 |pmid=2404717 |doi=10.2337/diacare.13.1.49}} (''For historical perspective, this review covers the concept just before the nature of the first of the specific molecular defects was discovered. It illustrates the significant change in the disease(s) referred to as MODY before and after 1990.'')
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| * {{cite journal |author=Fajans SS, Bell GI, Polonsky KS |title=Molecular mechanisms and clinical pathophysiology of maturity-onset diabetes of the young |journal=N. Engl. J. Med. |volume=345 |issue=13 |pages=971–80 |year=2001 |pmid=11575290 |doi=10.1056/NEJMra002168|url=http://content.nejm.org/cgi/content/extract/345/13/971?view=extractpmid=11575290}} (''An excellent overview of the modern concept of the 6 types of MODY.'')
| | [[Maturity onset diabetes of the young case study one|Case #1]] |
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| *[http://www.ncbi.nlm.nih.gov/books/bv.fcgi?call=bv.View..ShowTOC&rid=diabetes.TOC Dean L and McEntyre J, 2004.] '''The Genetic Landscape of Diabetes'''. Bethesda:NCBI, 2004. ''This is an entire online textbook on the complex genetics of the forms of diabetes. The chapter on MODY provides an up-to-date and concise overview of the molecular defects. Little expansion of clinical knowledge of the 6 types since 2001 has occurred.''
| | == External links == |
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| ==External links==
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| * [http://www.diabetesgenes.org Andrew Hattersley's Exeter and Oxford research groups] | | * [http://www.diabetesgenes.org Andrew Hattersley's Exeter and Oxford research groups] |
| * [http://www.athenadiagnostics.com/MODY Virtual Grand Rounds: "MODY" by William E. Winter]
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| [[Category:Diabetes]] | | [[Category:Diabetes]] |
| [[Category:Endocrinology]] | | [[Category:Endocrinology]] |
| | [[Category:Disease]] |
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| [[it:Maturity onset diabetes of the young]] | | [[it:Maturity onset diabetes of the young]] |
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