Methylenetetrahydrofolate Reductase (NADPH2)
5,10-Methylenetetrahydrofolate Reductase (FADH2)
Oxidoreductases Acting on CH-NH Group Donors
Methylenetetrahydrofolate Dehydrogenase (NADP)
Folic Acid
Polymorphism, Genetic
Genotype
5-Methyltetrahydrofolate-Homocysteine S-Methyltransferase
Hyperhomocysteinemia
Vitamin B 12
Ferredoxin-NADP Reductase
Factor V
Genetic Predisposition to Disease
Cystathionine beta-Synthase
Thymidylate Synthase
Thrombophilia
Case-Control Studies
Folic Acid Deficiency
Gene Frequency
Glycine Hydroxymethyltransferase
Riboflavin
Flavin-Adenine Dinucleotide
Homocystinuria
Prothrombin
Oxidoreductases
Alleles
Polymorphism, Single Nucleotide
Risk Factors
Formate-Tetrahydrofolate Ligase
Macedonia (Republic)
Point Mutation
S-Adenosylmethionine
Mutation
Vitamin B 6
Methenyltetrahydrofolate Cyclohydrolase
Odds Ratio
Neural Tube Defects
Betaine
FMN Reductase
Reduced Folate Carrier Protein
NADP
Polymerase Chain Reaction
Asian Continental Ancestry Group
Spinal Dysraphism
Methotrexate
Hydroxymethylglutaryl CoA Reductases
Polymorphism, Restriction Fragment Length
Amino Acid Metabolism, Inborn Errors
Transcobalamins
Pyridoxine
Dietary Supplements
Alcohol Oxidoreductases
Colorectal Neoplasms
Fluorodeoxyuridylate
Cytochrome-B(5) Reductase
Nitrite Reductases
Heterozygote
Deoxyribodipyrimidine Photo-Lyase
DNA Methylation
Genetic Association Studies
Glutathione Reductase
Thioredoxin-Disulfide Reductase
Tetrahydrofolate Dehydrogenase
Confidence Intervals
NADPH-Ferrihemoprotein Reductase
Oxidation-Reduction
Pharmacogenetics
Pteroylpolyglutamic Acids
Risk
Base Sequence
Pregnancy
Molecular Sequence Data
Oxidoreductases Acting on CH-CH Group Donors
Vascular Diseases
Dihydropteridine Reductase
Enzyme Stability
Haplotypes
Flavins
Reference Values
S-Adenosylhomocysteine
Cohort Studies
There are several factors that can contribute to hyperhomocysteinemia, including:
1. Genetic mutations: Some individuals may have genetic mutations that affect the enzymes involved in homocysteine metabolism, leading to elevated levels of homocysteine.
2. Vitamin deficiencies: Deficiencies in vitamins B6, B12, and folate can interfere with the metabolism of homocysteine, leading to elevated levels.
3. Kidney disease: The kidneys play a critical role in removing homocysteine from the body. Any damage to the kidneys or impairment in their function can lead to hyperhomocysteinemia.
4. Other medical conditions: Certain medical conditions, such as thyroid disorders and autoimmune diseases, can also contribute to hyperhomocysteinemia.
Elevated levels of homocysteine have been linked to several health problems, including:
1. Cardiovascular disease: High levels of homocysteine have been associated with an increased risk of heart disease and stroke.
2. Blood clots: Homocysteine can interfere with the normal blood clotting process, leading to an increased risk of blood clots and deep vein thrombosis.
3. Bone loss: Elevated levels of homocysteine have been linked to bone loss and an increased risk of osteoporosis.
4. Cognitive decline: Some studies suggest that high levels of homocysteine may be associated with cognitive decline and an increased risk of dementia.
Treatment for hyperhomocysteinemia typically involves addressing any underlying medical conditions, such as kidney disease or thyroid disorders, and making dietary changes to increase the intake of vitamin B6, folate, and other nutrients that help regulate homocysteine levels. In some cases, medications may be prescribed to lower homocysteine levels. Regular monitoring of homocysteine levels can help healthcare providers track the effectiveness of treatment and make any necessary adjustments.
Explanation: Genetic predisposition to disease is influenced by multiple factors, including the presence of inherited genetic mutations or variations, environmental factors, and lifestyle choices. The likelihood of developing a particular disease can be increased by inherited genetic mutations that affect the functioning of specific genes or biological pathways. For example, inherited mutations in the BRCA1 and BRCA2 genes increase the risk of developing breast and ovarian cancer.
The expression of genetic predisposition to disease can vary widely, and not all individuals with a genetic predisposition will develop the disease. Additionally, many factors can influence the likelihood of developing a particular disease, such as environmental exposures, lifestyle choices, and other health conditions.
Inheritance patterns: Genetic predisposition to disease can be inherited in an autosomal dominant, autosomal recessive, or multifactorial pattern, depending on the specific disease and the genetic mutations involved. Autosomal dominant inheritance means that a single copy of the mutated gene is enough to cause the disease, while autosomal recessive inheritance requires two copies of the mutated gene. Multifactorial inheritance involves multiple genes and environmental factors contributing to the development of the disease.
Examples of diseases with a known genetic predisposition:
1. Huntington's disease: An autosomal dominant disorder caused by an expansion of a CAG repeat in the Huntingtin gene, leading to progressive neurodegeneration and cognitive decline.
2. Cystic fibrosis: An autosomal recessive disorder caused by mutations in the CFTR gene, leading to respiratory and digestive problems.
3. BRCA1/2-related breast and ovarian cancer: An inherited increased risk of developing breast and ovarian cancer due to mutations in the BRCA1 or BRCA2 genes.
4. Sickle cell anemia: An autosomal recessive disorder caused by a point mutation in the HBB gene, leading to defective hemoglobin production and red blood cell sickling.
5. Type 1 diabetes: An autoimmune disease caused by a combination of genetic and environmental factors, including multiple genes in the HLA complex.
Understanding the genetic basis of disease can help with early detection, prevention, and treatment. For example, genetic testing can identify individuals who are at risk for certain diseases, allowing for earlier intervention and preventive measures. Additionally, understanding the genetic basis of a disease can inform the development of targeted therapies and personalized medicine."
There are several types of thrombophilia, including:
1. Factor V Leiden: This is the most common inherited thrombophilia and is caused by a mutation in the Factor V gene.
2. Prothrombin G20210A: This is another inherited thrombophilia that is caused by a mutation in the Prothrombin gene.
3. Protein C and S deficiency: These are acquired deficiencies of protein C and S, which are important proteins that help to prevent blood clots.
4. Antiphospholipid syndrome: This is an autoimmune disorder that causes the body to produce antibodies against phospholipids, which can lead to blood clots.
5. Cancer-associated thrombophilia: This is a condition where cancer patients are at a higher risk of developing blood clots due to their cancer and its treatment.
6. Hormone-related thrombophilia: This is a condition where hormonal changes, such as those that occur during pregnancy or with the use of hormone replacement therapy, increase the risk of blood clots.
7. Inherited platelet disorders: These are rare conditions that affect the way platelets function and can increase the risk of blood clots.
8. Anti-cardiolipin antibodies: These are autoantibodies that can cause blood clots.
9. Lupus anticoagulant: This is an autoantibody that can cause blood clots.
10. Combined genetic and acquired risk factors: Some people may have a combination of inherited and acquired risk factors for thrombophilia.
Thrombophilia can be diagnosed through various tests, including:
1. Blood tests: These tests measure the levels of certain proteins in the blood that are associated with an increased risk of blood clots.
2. Genetic testing: This can help identify inherited risk factors for thrombophilia.
3. Imaging tests: These tests, such as ultrasound and venography, can help doctors visualize the blood vessels and look for signs of blood clots.
4. Thrombin generation assay: This test measures the body's ability to produce thrombin, a protein that helps form blood clots.
5. Platelet function tests: These tests assess how well platelets work and whether they are contributing to the development of blood clots.
Treatment for thrombophilia usually involves medications to prevent or dissolve blood clots, as well as measures to reduce the risk of developing new clots. These may include:
1. Anticoagulant drugs: These medications, such as warfarin and heparin, are used to prevent blood clots from forming.
2. Thrombolytic drugs: These medications are used to dissolve blood clots that have already formed.
3. Compression stockings: These stockings can help reduce swelling and improve blood flow in the affected limb.
4. Elevating the affected limb: This can help reduce swelling and improve blood flow.
5. Avoiding long periods of immobility: This can help reduce the risk of developing blood clots.
In some cases, surgery may be necessary to remove a blood clot or repair a damaged blood vessel. In addition, people with thrombophilia may need to make lifestyle changes, such as avoiding long periods of immobility and taking regular breaks to move around, to reduce their risk of developing blood clots.
Overall, the prognosis for thrombophilia is generally good if the condition is properly diagnosed and treated. However, if left untreated, thrombophilia can lead to serious complications, such as pulmonary embolism or stroke, which can be life-threatening. It is important for people with thrombophilia to work closely with their healthcare provider to manage the condition and reduce the risk of complications.
1. Anemia: Folic acid plays a critical role in the production of red blood cells, so a deficiency can lead to anemia, which can cause fatigue, weakness, and shortness of breath.
2. Birth defects: Folic acid is crucial for fetal development during pregnancy, and a deficiency can increase the risk of birth defects such as spina bifida and cleft palate.
3. Heart disease: Folic acid helps to regulate homocysteine levels in the blood, which are associated with an increased risk of heart disease and stroke.
4. Neurological problems: Folic acid is important for the health of the nervous system, and a deficiency can lead to neurological problems such as cognitive impairment, mood disturbances, and seizures.
5. Poor wound healing: Folic acid is necessary for the production of collagen, which is important for wound healing. A deficiency can lead to slow or poor wound healing.
6. Increased risk of cancer: Some studies suggest that a folic acid deficiency may increase the risk of certain types of cancer, such as colon cancer.
7. Hair loss: Folic acid is important for hair growth, and a deficiency can lead to hair loss.
8. Skin problems: Folic acid is important for skin health, and a deficiency can lead to skin problems such as dry, flaky skin and mouth sores.
9. Mood changes: Folic acid plays a role in the production of neurotransmitters, which are chemicals that regulate mood. A deficiency can lead to mood changes such as depression and anxiety.
10. Fatigue: Folic acid is important for energy metabolism, and a deficiency can lead to fatigue and weakness.
Folic acid deficiency can be caused by a number of factors, including:
1. Poor diet: A diet that is low in folate-rich foods can lead to a deficiency.
2. Malabsorption: Certain medical conditions such as celiac disease and Crohn's disease can lead to malabsorption of folic acid.
3. Pregnancy and lactation: Women who are pregnant or breastfeeding have a higher need for folic acid, and may be at risk for deficiency if they do not consume enough.
4. Alcoholism: Heavy alcohol consumption can interfere with the absorption of folic acid.
5. Certain medications: Some medications, such as antacids and proton pump inhibitors, can interfere with the absorption of folic acid.
To diagnose a folic acid deficiency, a healthcare provider may perform a physical exam, take a medical history, and order blood tests to measure folic acid levels. Treatment for a folic acid deficiency typically involves dietary changes and supplements. Dietary changes may include consuming more folate-rich foods, such as leafy green vegetables, legumes, and whole grains. Supplements may include folic acid tablets or liquid supplements. In severe cases of deficiency, injections of folic acid may be necessary. It is important to seek medical attention if you suspect a folic acid deficiency, as untreated deficiencies can lead to serious health problems.
Treatment for homocystinuria typically involves a combination of dietary modifications and nutritional supplements to manage the symptoms and prevent long-term complications. In some cases, medication may also be prescribed to reduce the levels of homocysteine in the blood.
The prognosis for individuals with homocystinuria varies depending on the severity of the condition and the effectiveness of treatment. Some individuals with mild forms of the disorder may experience few or no symptoms, while those with more severe forms may have significant developmental delays and disabilities. With appropriate management, however, many individuals with homocystinuria can lead active and fulfilling lives.
There are several types of NTDs, including:
1. Anencephaly: A severe form of NTD where a large portion of the neural tube does not develop, resulting in the absence of a major part of the brain and skull.
2. Spina Bifida: A type of NTD where the spine does not close properly, leading to varying degrees of neurological damage and physical disability.
3. Encephalocele: A type of NTD where the brain or meninges protrude through a opening in the skull.
4. Meningomyelocele: A type of NTD where the spinal cord and meninges protrude through a opening in the back.
Causes and risk factors:
1. Genetic mutations: Some NTDs can be caused by genetic mutations that affect the development of the neural tube.
2. Environmental factors: Exposure to certain chemicals, such as folic acid deficiency, has been linked to an increased risk of NTDs.
3. Maternal health: Women with certain medical conditions, such as diabetes or obesity, are at a higher risk of having a child with NTDs.
Symptoms and diagnosis:
1. Anencephaly: Severely underdeveloped brain, absence of skull, and often death shortly after birth.
2. Spina Bifida: Difficulty walking, weakness or paralysis in the legs, bladder and bowel problems, and intellectual disability.
3. Encephalocele: Protrusion of brain or meninges through a opening in the skull, which can cause developmental delays, seizures, and intellectual disability.
4. Meningomyelocele: Protrusion of spinal cord and meninges through a opening in the back, which can cause weakness or paralysis in the legs, bladder and bowel problems, and intellectual disability.
Treatment and management:
1. Surgery: Depending on the type and severity of the NTD, surgery may be necessary to close the opening in the skull or back, or to release compressed tissue.
2. Physical therapy: To help improve mobility and strength in affected limbs.
3. Occupational therapy: To help with daily activities and fine motor skills.
4. Speech therapy: To help with communication and language development.
5. Medications: To manage seizures, pain, and other symptoms.
6. Nutritional support: To ensure adequate nutrition and growth.
7. Supportive care: To help manage the physical and emotional challenges of living with an NTD.
Prevention:
1. Folic acid supplements: Taking a daily folic acid supplement during pregnancy can help prevent NTDs.
2. Good nutrition: Eating a balanced diet that includes foods rich in folate, such as leafy greens, citrus fruits, and beans, can help prevent NTDs.
3. Avoiding alcohol and tobacco: Both alcohol and tobacco use have been linked to an increased risk of NTDs.
4. Getting regular prenatal care: Regular check-ups with a healthcare provider during pregnancy can help identify potential problems early on and reduce the risk of NTDs.
5. Avoiding infections: Infections such as rubella (German measles) can increase the risk of NTDs, so it's important to avoid exposure to these infections during pregnancy.
It's important to note that not all NTDs can be prevented, and some may be caused by genetic factors or other causes that are not yet fully understood. However, taking steps to maintain good health and getting regular prenatal care can help reduce the risk of NTDs and improve outcomes for babies born with these conditions.
There are several types of spinal dysraphism, including:
1. Spina bifida: This is the most common type of spinal dysraphism, and it occurs when the spine fails to close properly during fetal development. As a result, the spinal cord and meninges (the protective covering of the spinal cord) are exposed and can be damaged.
2. Myelomeningocele: This is a type of spina bifida that occurs when the spinal cord protrudes through an opening in the spine. It is often associated with hydrocephalus (a buildup of fluid in the brain).
3. Meningomyelocele: This is a type of spinal dysraphism that occurs when the meninges protrude through an opening in the spine, but the spinal cord remains within the spine.
4. Diastematomyelia: This is a rare type of spinal dysraphism that occurs when there is a separation or division of the spinal cord.
5. Hemicord syndrome: This is a rare type of spinal dysraphism that occurs when one half of the spinal cord is underdeveloped or absent.
The symptoms of spinal dysraphism can vary depending on the severity and location of the disorder. They may include:
* Muscle weakness or paralysis
* Loss of sensation in the affected limbs
* Bladder and bowel dysfunction
* Hydrocephalus (a buildup of fluid in the brain)
* Neurological problems such as seizures, learning disabilities, and developmental delays.
Treatment for spinal dysraphism depends on the severity of the disorder and may include:
* Surgery to repair or close the opening in the spine
* Shunting procedures to drain excess fluid from the brain
* Physical therapy to improve muscle strength and mobility
* Occupational therapy to help with daily activities and developmental delays.
The long-term outlook for individuals with spinal dysraphism varies depending on the severity of the disorder and the effectiveness of treatment. Some individuals may experience significant improvement with surgery and other treatments, while others may have ongoing neurological problems and developmental delays. It is important for individuals with spinal dysraphism to receive regular medical care and follow-up to monitor their condition and address any complications that may arise.
A condition in which spontaneous abortions occur repeatedly, often due to an underlying cause such as a uterine anomaly or infection. Also called recurrent spontaneous abortion.
Synonym(s): habitual abortion, recurrent abortion, spontaneous abortion.
Antonym(s): multiple pregnancy, retained placenta.
Example Sentence: "The patient had experienced four habitual abortions in the past year and was concerned about her ability to carry a pregnancy to term."
There are several types of inborn errors of amino acid metabolism, including:
1. Phenylketonuria (PKU): This is the most common inborn error of amino acid metabolism and is caused by a deficiency of the enzyme phenylalanine hydroxylase. This enzyme is needed to break down the amino acid phenylalanine, which is found in many protein-containing foods. If phenylalanine is not properly broken down, it can build up in the blood and brain and cause serious health problems.
2. Maple syrup urine disease (MSUD): This is a rare genetic disorder that affects the breakdown of the amino acids leucine, isoleucine, and valine. These amino acids are important for growth and development, but if they are not properly broken down, they can build up in the blood and cause serious health problems.
3. Homocystinuria: This is a rare genetic disorder that affects the breakdown of the amino acid methionine. Methionine is important for the body's production of proteins and other compounds, but if it is not properly broken down, it can build up in the blood and cause serious health problems.
4. Arginase deficiency: This is a rare genetic disorder that affects the breakdown of the amino acid arginine. Arginine is important for the body's production of nitric oxide, a compound that helps to relax blood vessels and improve blood flow.
5. Citrullinemia: This is a rare genetic disorder that affects the breakdown of the amino acid citrulline. Citrulline is important for the body's production of proteins and other compounds, but if it is not properly broken down, it can build up in the blood and cause serious health problems.
6. Tyrosinemia: This is a rare genetic disorder that affects the breakdown of the amino acid tyrosine. Tyrosine is important for the body's production of proteins and other compounds, but if it is not properly broken down, it can build up in the blood and cause serious health problems.
7. Maple syrup urine disease (MSUD): This is a rare genetic disorder that affects the breakdown of the amino acids leucine, isoleucine, and valine. These amino acids are important for growth and development, but if they are not properly broken down, they can build up in the blood and cause serious health problems.
8. PKU (phenylketonuria): This is a rare genetic disorder that affects the breakdown of the amino acid phenylalanine. Phenylalanine is important for the body's production of proteins and other compounds, but if it is not properly broken down, it can build up in the blood and cause serious health problems.
9. Methionine adenosyltransferase (MAT) deficiency: This is a rare genetic disorder that affects the breakdown of the amino acid methionine. Methionine is important for the body's production of proteins and other compounds, but if it is not properly broken down, it can build up in the blood and cause serious health problems.
10. Homocystinuria: This is a rare genetic disorder that affects the breakdown of the amino acid homocysteine. Homocysteine is important for the body's production of proteins and other compounds, but if it is not properly broken down, it can build up in the blood and cause serious health problems.
It is important to note that these disorders are rare and affect a small percentage of the population. However, they can be serious and potentially life-threatening, so it is important to be aware of them and seek medical attention if symptoms persist or worsen over time.
The causes of colorectal neoplasms are not fully understood, but factors such as age, genetics, diet, and lifestyle have been implicated. Symptoms of colorectal cancer can include changes in bowel habits, blood in the stool, abdominal pain, and weight loss. Screening for colorectal cancer is recommended for adults over the age of 50, as it can help detect early-stage tumors and improve survival rates.
There are several subtypes of colorectal neoplasms, including adenomas (which are precancerous polyps), carcinomas (which are malignant tumors), and lymphomas (which are cancers of the immune system). Treatment options for colorectal cancer depend on the stage and location of the tumor, but may include surgery, chemotherapy, radiation therapy, or a combination of these.
Research into the causes and treatment of colorectal neoplasms is ongoing, and there has been significant progress in recent years. Advances in screening and treatment have improved survival rates for patients with colorectal cancer, and there is hope that continued research will lead to even more effective treatments in the future.
1. Atherosclerosis: A condition in which plaque builds up inside the arteries, causing them to narrow and harden. This can lead to heart disease, heart attack, or stroke.
2. Hypertension: High blood pressure that can damage blood vessels and increase the risk of heart disease, stroke, and other conditions.
3. Peripheral artery disease (PAD): A condition in which the blood vessels in the legs and arms become narrowed or blocked, leading to pain, cramping, and weakness in the affected limbs.
4. Raynaud's phenomenon: A condition that causes blood vessels in the hands and feet to constrict in response to cold temperatures or stress, leading to discoloration, numbness, and tissue damage.
5. Deep vein thrombosis (DVT): A condition in which a blood clot forms in the deep veins of the legs, often caused by immobility or injury.
6. Varicose veins: Enlarged, twisted veins that can cause pain, swelling, and cosmetic concerns.
7. Angioplasty: A medical procedure in which a balloon is used to open up narrowed blood vessels, often performed to treat peripheral artery disease or blockages in the legs.
8. Stenting: A medical procedure in which a small mesh tube is placed inside a blood vessel to keep it open and improve blood flow.
9. Carotid endarterectomy: A surgical procedure to remove plaque from the carotid arteries, which supply blood to the brain, to reduce the risk of stroke.
10. Bypass surgery: A surgical procedure in which a healthy blood vessel is used to bypass a blocked or narrowed blood vessel, often performed to treat coronary artery disease or peripheral artery disease.
Overall, vascular diseases can have a significant impact on quality of life and can increase the risk of serious complications such as stroke, heart attack, and amputation. It is important to seek medical attention if symptoms persist or worsen over time, as early diagnosis and treatment can help to prevent long-term damage and improve outcomes.