A rare but serious form of acute adult leukemia. The disease occurs when chronic lymphocytic leukemia transforms into diffuse large cell lymphoma which is a fast-growing form of lymphoma. The condition tends to be more common in older adults.
Rickets is a softening of bones in children potentially leading to fractures and deformity. Rickets is among the most frequent childhood diseases in many developing countries. The predominant cause is a vitamin D deficiency, but lack of adequate calcium in the diet may also lead to rickets (cases of severe diarrhoea and vomiting may be the cause of the deficiency). Although it can occur in adults, the majority of cases occur in children suffering from severe malnutrition, usually resulting from famine or starvation during the early stages of childhood. Osteomalacia is the term used to describe a similar condition occurring in adults, generally due to a deficiency of vitamin D. The origin of the word "rickets" is probably from the Old English dialect word 'wrickken', to twist. The Greek derived word "rachitis" (meaning "inflammation of the spine") was later adopted as the scientific term for rickets, due chiefly to the words' similarity in sound. In many languages it is known as "English disease".
Rickettsia is a genus of motile, Gram-negative, non-sporeforming, highly pleomorphic bacteria that can present as cocci (0.1 μm in diameter), rods (1-4 μm long) or thread-like (10 μm long). Obligate intracellular parasites, the Rickettsia depend on entry, growth, and replication within the cytoplasm of eukaryotic host cells (typically endothelial cells). Because of this, Rickettsia cannot live in artificial nutrient environments and are grown either in tissue or embryo cultures (typically, chicken embryos are used). In the past they were regarded as microorganisms positioned somewhere between viruses and true bacteria. The majority of Rickettsia bacteria are susceptible to antibiotics of the tetracycline group. Rickettsia species are carried as parasites by many ticks, fleas, and lice, and cause diseases such as typhus, rickettsialpox, Boutonneuse fever, African Tick Bite Fever, Rocky Mountain spotted fever, Australian Tick Typhus, Flinders Island Spotted Fever and Queensland Tick Typhus [2] in human beings. They have also been associated with a range of plant diseases. Like viruses, they only grow inside living cells. The name rickettsia is often used for any member of the Rickettsiales. They are thought to be the closest living relatives to bacteria that were the origin of the mitochondria organelle that exists inside most eukaryotic cells.
A disease caused by infection with rickettsial bacteria which are transmitted by arthropods such as ticks, mites and lice. Different rickettsial bacteria can cause different types of infections such as typhus, spotted fever and trench fever. Symptoms can vary somewhat between the different types.
A rare genetic disorder characterized by underdeveloped or absent teeth and craniofacial and eye abnormalities.
Specialists recognize two genetic forms of Rieger syndrome. Type I occurs as a result of mutations on chromosome 4 and Type II results from mutations on chromosome 13.
A rare disorder where abnormal development of the front portion of the eye causes glaucoma and impaired vision. Other abnormalities are also present.
Right atrium familial dilatation (medical condition): An inherited heart abnormality where the right atrium is dilated.
An underdeveloped right heart ventricle which is smaller than normal and is thus less able to pump blood efficiently to the lungs. The age at which the symptoms become apparent varies depending on the severity of the defect.
A muscle wasting disorder mainly involving the muscles in the arms, legs, face, neck, spine and heart. Symptoms generally only occur in males but female carriers may have some symptoms.
Ring chromosome 14 syndrome (ring 14, ring 14 syndrome, ring chromosome 14) is a very rare human chromosome abnormality. It occurs when one or both of the telomeres that mark the ends of chromosome 14 are lost allowing the now uncapped ends to fuse together forming a ring chromosome. It causes a number of serious health issues, most notably recurrent treatment-resistant seizures and intellectual disability.
A rare eye disorder which results in the appearance of a dark ring around the cornea.
"Ringed hair" is a peculiar disease in which the hair seems banded by alternating segments of light and dark color when seen in reflected light.
A rare dominantly inherited disorder involving skeletal muscle contractions which produces a visible rippling affect.
Rippling muscle disease, 1: A rare dominantly inherited disorder involving skeletal muscle contractions which produces a visible rippling affect. Type 1 involves a defect on chromosome 1q41.
Roberts syndrome is an extremely rare genetic disorder that is characterized by mild to severe prenatal retardation or disruption of cell division, leading to malformation of the bones in the skull, face, arms, and legs.
The Syndrome is both autosomal, in that there are equal numbers of copies of the gene in both males and females, and recessive, meaning the child must inherit the defective gene from both parents. The mutation causes cell division to occur slowly or unevenly, and the cells with abnormal genetic content die. Roberts syndrome can affect both males and females. Although the disorder is rare, the affected group is diverse. The mortality rate is high in severely affected individuals.
A very rare syndrome characterized mainly by missing fingers, small jaw, tonge anomaly and a cleft palate.
Robinow Sorauf syndrome is a rare disorder characterized by facial and dental abnormalities as well as a partial or complete duplication of the end bone of the big toe.
A rare genetic disorder characterized by a flat face, short forearms, vertebral anomalies and hypoplastic genitalia.
A very rare syndrome characterized by deafness, malformed nails and other abnormalities.
A rare inherited disorder characterized by the development of many small lipomas. The lipomas are present mainly on the trunk, upper thighs and forearms. They are generally harmless though sometimes painful and can be removed surgically.
Rocky Mountain spotted fever is the most lethal and most frequently reported rickettsial illness in the United States. It has been diagnosed throughout the Americas. Some synonyms for Rocky Mountain spotted fever in other countries include “tick typhus,” “Tobia fever” (Colombia), “São Paulo fever” or “febre maculosa” (Brazil), and “fiebre manchada” (Mexico). It should not be confused with the viral tick-borne infection, Colorado tick fever. The disease is caused by Rickettsia rickettsii, a species of bacterium that is spread to humans by ixodid (hard) ticks. Initial signs and symptoms of the disease include sudden onset of fever, headache, and muscle pain, followed by development of rash. The disease can be difficult to diagnose in the early stages, and without prompt and appropriate treatment it can be fatal
one of a group of diseases that cause problems with the tone and contraction of skeletal muscles
A rare genetic disorder characterized primarily by dental symptoms, opening in the roof of the mouth (cleft palate) and missing fingers giving the hands a claw like appearance.
A rare disorder characterized by severe eye malformations, short stature and hair and dental anomalies.
A rare syndrome characterized by abnormal bone growth, immune deficiency and an eye disorder.
A rare condition characterized by absence of the vagina and uterine abnormalities.
A very rare syndrome characterized mainly by the absence of various internal reproductive structures.
An abnormality of the gallbladder wall where small pouches of the mucus layer develop abnormal sinuses or spaces within that gallbladder lining.
This hitherto unknown and dominantly inherited disorder is characterized by vermiculate atrophoderma, milia, hypotrichosis, trichoepitheliomas, basal cell carcinomas and peripheral vasodilation with cyanosis. It has been present in the family reported for at least four generations. The lesions become visible in late childhood and are most pronounced on the face. Basal cell carcinomas may develop around the age of 35. Histological observations during the early stage include irregularly distributed and atrophic hair follicles, milia, dilated dermal vessels, lack of elastin or elastin in clumps. After light irradiation a tendency to increased repair activity was observed both in epidermis and in the dermal fibroblasts. On exposure to cold the change in the skin temperature of the hands compared with that in the controls was insignificant. The response to adrenalin iontophoresis was weak.