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LIG4 Syndrome
LIG4 syndrome (also known as Ligase IV syndrome) is an extremely rare condition caused by mutations in the DNA Ligase IV (LIG4) gene. Some mutations in this gene are associated with a resistance against multiple myeloma and Severe Combined Immunodeficiency. Severity of symptoms depends on the degree of reduced enzymatic activity of Ligase IV or gene expression. Ligase IV is a critical component of the non-homologous end joining (NHEJ) mechanism that repairs DNA double-strand breaks. It is employed in repairing DNA double-strand breaks caused by reactive oxygen species produced by normal metabolism, or by DNA damaging agents such as ionizing radiation. NHEJ is also used to repair the DNA double-strand break intermediates that occur in the production of T and B lymphocyte receptors. As DNA ligase IV is essential in V(D)J recombination, the mechanism by which immunoglobulins, B cell and T cell receptors are formed, patients with LIG4 syndrome may have less effective or de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LIG4
DNA ligase 4 is an enzyme that in humans is encoded by the LIG4 gene. Function The protein encoded by this gene is an ATP-dependent DNA ligase that joins double-strand breaks during the non-homologous end joining pathway of double-strand break repair. It is also essential for V(D)J recombination. Lig4 forms a complex with XRCC4, and further interacts with the DNA-dependent protein kinase (DNA-PK) and XLF/Cernunnos, which are also required for NHEJ. The crystal structure of the Lig4/XRCC4 complex has been resolved. Defects in this gene are the cause of LIG4 syndrome. The yeast homolog of Lig4 is Dnl4. LIG4 Syndrome In humans, deficiency of DNA ligase 4 results in a clinical condition known as LIG4 syndrome. This syndrome is characterized by cellular radiation sensitivity, growth retardation, developmental delay, microcephaly, facial dysmorphisms, increased disposition to leukemia, variable degrees of immunodeficiency and reduced number of blood cells. Haematopoietic st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seckel Syndrome
Seckel syndrome, or microcephalic primordial dwarfism (also known as bird-headed dwarfism, Harper's syndrome, Virchow–Seckel dwarfism and bird-headed dwarf of Seckel) is an extremely rare congenital nanosomic disorder. Inheritance is autosomal recessive. It is characterized by intrauterine growth restriction and postnatal dwarfism with a small head, narrow bird-like face with a beak-like nose, large eyes with down-slanting palpebral fissures, receding mandible and intellectual disability. A mouse model has been developed. This mouse model is characterized by a severe deficiency of ATR protein. These mice have high levels of replicative stress and DNA damage. Adult Seckel mice display accelerated ageing. These findings are consistent with the DNA damage theory of aging. Symptoms and signs Symptoms include: * intellectual disability (more than half of the patients have an IQ below 50) * microcephaly * sometimes pancytopenia (low blood counts) * cryptorchidism in males * low birth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Cutaneous Conditions
Many skin conditions affect the human integumentary system—the organ system covering the entire surface of the body and composed of skin, hair, nails, and related muscle and glands. The major function of this system is as a barrier against the external environment. The skin weighs an average of four kilograms, covers an area of two square metres, and is made of three distinct layers: the epidermis, dermis, and subcutaneous tissue. The two main types of human skin are: glabrous skin, the hairless skin on the palms and soles (also referred to as the "palmoplantar" surfaces), and hair-bearing skin.Burns, Tony; ''et al''. (2006) ''Rook's Textbook of Dermatology CD-ROM''. Wiley-Blackwell. . Within the latter type, the hairs occur in structures called pilosebaceous units, each with hair follicle, sebaceous gland, and associated arrector pili muscle. In the embryo, the epidermis, hair, and glands form from the ectoderm, which is chemically influenced by the underlying mesoderm th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
T-cell Leukemia
T-cell leukemia describes several different types of lymphoid leukemia which affect T cells. Types include: * Large granular lymphocytic leukemia * Adult T-cell leukemia/lymphoma * T-cell prolymphocytic leukemia In practice, it can be hard to distinguish T-cell leukemia from T-cell lymphoma T-cell lymphoma is a rare form of cancerous lymphoma affecting T-cells. Lymphoma arises mainly from the uncontrolled proliferation of T-cells and can become cancerous. T-cell lymphoma is categorized under Non-Hodgkin lymphoma (NHL) and represents ..., and they are often grouped together. References External links {{DEFAULTSORT:T-Cell Leukemia Lymphocytic leukemia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type II Diabetes
Type 2 diabetes, formerly known as adult-onset diabetes, is a form of diabetes mellitus that is characterized by high blood sugar, insulin resistance, and relative lack of insulin. Common symptoms include increased thirst, frequent urination, and unexplained weight loss. Symptoms may also include increased hunger, feeling tired, and sores that do not heal. Often symptoms come on slowly. Long-term complications from high blood sugar include heart disease, strokes, diabetic retinopathy which can result in blindness, kidney failure, and poor blood flow in the limbs which may lead to amputations. The sudden onset of hyperosmolar hyperglycemic state may occur; however, ketoacidosis is uncommon. Type 2 diabetes primarily occurs as a result of obesity and lack of exercise. Some people are genetically more at risk than others. Type 2 diabetes makes up about 90% of cases of diabetes, with the other 10% due primarily to type 1 diabetes and gestational diabetes. In type 1 diabete ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypothyroidism
Hypothyroidism (also called ''underactive thyroid'', ''low thyroid'' or ''hypothyreosis'') is a disorder of the endocrine system in which the thyroid gland does not produce enough thyroid hormone. It can cause a number of symptoms, such as poor ability to tolerate cold, a feeling of tiredness, constipation, slow heart rate, depression, and weight gain. Occasionally there may be swelling of the front part of the neck due to goiter. Untreated cases of hypothyroidism during pregnancy can lead to delays in growth and intellectual development in the baby or congenital iodine deficiency syndrome. Worldwide, too little iodine in the diet is the most common cause of hypothyroidism. Hashimoto's thyroiditis is the most common cause of hypothyroidism in countries with sufficient dietary iodine. Less common causes include previous treatment with radioactive iodine, injury to the hypothalamus or the anterior pituitary gland, certain medications, a lack of a functioning thyroid at bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telangiectasia
Telangiectasias, also known as spider veins, are small dilated blood vessels that can occur near the surface of the skin or mucous membranes, measuring between 0.5 and 1 millimeter in diameter. These dilated blood vessels can develop anywhere on the body, but are commonly seen on the face around the nose, cheeks and chin. Dilated blood vessels can also develop on the legs, although when they occur on the legs, they often have underlying venous reflux or "hidden varicose veins" (see Venous hypertension section below). When found on the legs, they are found specifically on the upper thigh, below the knee joint and around the ankles. Many patients with spider veins seek the assistance of physicians who specialize in vein care or peripheral vascular disease. These physicians are called vascular surgeons or phlebologists. More recently, interventional radiologists have started treating venous problems. Some telangiectasias are due to developmental abnormalities that can closely mimic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Psoriasis
Psoriasis is a long-lasting, noncontagious autoimmune disease characterized by raised areas of abnormal skin. These areas are red, pink, or purple, dry, itchy, and scaly. Psoriasis varies in severity from small, localized patches to complete body coverage. Injury to the skin can trigger psoriatic skin changes at that spot, which is known as the Koebner phenomenon. The five main types of psoriasis are plaque, guttate, inverse, pustular, and erythrodermic. Plaque psoriasis, also known as psoriasis vulgaris, makes up about 90% of cases. It typically presents as red patches with white scales on top. Areas of the body most commonly affected are the back of the forearms, shins, navel area, and scalp. Guttate psoriasis has drop-shaped lesions. Pustular psoriasis presents as small, noninfectious, pus-filled blisters. Inverse psoriasis forms red patches in skin folds. Erythrodermic psoriasis occurs when the rash becomes very widespread, and can develop from any of the other types. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photosensitivity In Humans
Light sensitivity or photosensitivity refers to a notable or increased reactivity to light. Apart from vision, human beings have many physiological and psychological responses to light. In rare individuals an atypical response may result in serious discomfort, disease, or injury. Some drugs have a photosensitizing effect. Properties of natural or artificial light that may abnormally affect people include: * Timing of light (upset of normal circadian rhythms, seasonal affective disorder, sleep disorders) * Intensity of light (photophobia, sunburn, skin cancer) * Wavelength of light (in lupus, urticaria) * Rapid flickers in intensity of light may trigger or aggravate photosensitive epilepsy, epileptic seizure, or migraine headaches. 2 Photoaggravated Disordersat European Dermatology Forum *Atopic eczema *Mastocytosis *Mast cell activation syndrome *Histamine intolerance *Erythema multiforme *Seborrhoeic dermatitis *Autoimmune bullous diseases ( immunobullous diseases) *Mycosis fungo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Growth Retardation
Delayed milestone, also called developmental delays, is used to describe the condition where a child does not reach one of these stages at the expected age. However, in most cases, a wide variety of ages can be considered normal, and not a cause for medical concern. Milestones are often measured using percentiles, and for many milestones a value between the 5th and 95th percentile does not require intervention, though values towards the edges of that range can be associated with other medical conditions. It is not possible to treat. It has been suggested that measurement of posture sway may be an early indicator. References External links - Information for parents on early childhood development and developmental disabilities "Recognizing Developmental Delays in Children" WebMD WebMD is an American corporation known primarily as an online publisher of news and information pertaining to human health and well-being. The site includes information pertaining to drugs. It is one ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microcephaly
Microcephaly (from New Latin ''microcephalia'', from Ancient Greek μικρός ''mikrós'' "small" and κεφαλή ''kephalé'' "head") is a medical condition involving a smaller-than-normal head. Microcephaly may be present at birth or it may develop in the first few years of life. Since brain growth is correlated with head growth, people with this disorder often have an intellectual disability, poor motor function, poor speech, abnormal facial features, seizures and dwarfism. The disorder is caused by a disruption to the genetic processes that form the brain early in pregnancy, though the cause is not identified in most cases. Many genetic syndromes can result in microcephaly, including chromosomal and single-gene conditions, though almost always in combination with other symptoms. Mutations that result solely in microcephaly (primary microcephaly) exist but are less common. External toxins to the embryo, such as alcohol during pregnancy or vertically transmitted infec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
