Diseases

Nance-Horan syndrome

Nance-Horan syndrome is a rare genetic disorder that may be evident at birth (congenital). It is primarily characterized by abnormalities of the teeth and clouding of the lens of the eyes (congenital cataracts), resulting in poor vision. Additional eye (ocular) abnormalities are also often present, such as unusual smallness of the front, clear portion of the eye through which light passes (microcornea) and involuntary, rapid, rhythmic eye movements (nystagmus). In some cases, the disorder may also be associated with additional physical abnormalities and/or intellectual impairment. The range and severity of symptoms may vary greatly from one person to another, including among affected members of the same family.

Nance-Horan syndrome is inherited as an X-linked trait that it is usually fully expressed in males only. However, females who carry a single copy of the disease gene (heterozygotes) may manifest some of the symptoms and findings associated with the disorder. These may include microcornea and/or clouding of the lens of the eyes (posterior sutural cataract). Symptoms are less severe than those of affected males, potentially causing only slightly decreased clearness or clarity of vision (visual acuity). In some cases, abnormalities of the teeth may also be present. Intellectual impairment rarely occurs in females.

The disorder is present at birth (congenital). Fewer than 50 families (kindreds) have been described in the medical literature. The exact incidence of the disorder is unknown. 

Narcolepsy

Narcolepsy is a chronic brain disorder that involves poor control of sleep-wake cycles. People with narcolepsy have episodes of extreme daytime sleepiness and sudden, irresistible bouts of sleep (called "sleep attacks") that can occur at any time, and may last from seconds or minutes. Other signs and symptoms may include cataplexy (a sudden loss of muscle tone that makes a person go limp or unable to move); vivid dream-like images or hallucinations; and/or total paralysis just before falling asleep or after waking-up. Narcolepsy may have several causes, the most common being low levels of the neurotransmitter hypocretin (for various possible reasons). The disorder is usually sporadic but some cases are familial. There is no cure, but some symptoms can be managed with medicines and lifestyle changes.

NARP Syndrome

Neuropathy, ataxia, and retinitis pigmentosa (NARP) is a clinically heterogeneous progressive condition characterized by a combination of proximal neurogenic muscle weakness, sensory-motor neuropathy, ataxia, and pigmentary retinopathy.

The prevalence of NARP is unknown. This disorder is probably less common than a similar but more severe condition, Leigh syndrome, which affects about 1 in 40,000 people.

Nasal polyposis, familial

Nasal polyposis, familial ( also known as nose polyposis, familial) is a familial condition characterized by the development of nasal polyps.

Nasodigitoacoustic syndrome

Nasodigitoacoustic syndrome is a rare congenital syndrome first described by J.A. Keipert and colleagues in 1973. The syndrome is characterized by a misshaped nose, broad thumbs and halluces (the big toes), brachydactyly, sensorineural hearing loss, facial features such as hypertelorism (unusually wide-set eyes), and developmental delay.

The incidence of the syndrome has not been determined, but it is considered to affect less than 200,000 people in the United States, and no greater than 1 per 2,000 in Europe.

Nasopharyngeal carcinoma

Nasopharyngeal carcinoma is the most common cancer originating in the nasopharynx, the uppermost region of the pharynx ("throat"), behind the nose where the nasal passages and auditory tubes join the remainder of the upper respiratory tract. NPC occurs in children and adults. NPC differs significantly from other cancers of the head and neck in its occurrence, causes, clinical behavior, and treatment. It is vastly more common in certain regions of East Asia and Africa than elsewhere, with viral, dietary and genetic factors implicated in its causation. It is most common in males. It is a squamous cell carcinoma or an undifferentiated type. Squamous epithelial cells are a flat type of cell found in the skin and the membranes that line some body cavities. Differentiation means how different the cancer cells are from normal cells. Undifferentiated is a word used to describe cells that do not have their mature features or functions.

Nathalie syndrome

A very rare syndrome characterized mainly by deafness, cataracts and skeletal abnormalities

Native American myopathy

A rare genetic disorder characterized by muscle disease from birth, cleft palate and malignant hyperthermia.

Navajo neurohepatopathy

A rare genetic disease found in Navajo populations. It involves peripheral nerve degeneration, liver disease and corneal ulcers. The genetic disease is believed to be caused by maternal exposure to uranium from waters contaminated by old mines

Navajo poikiloderma

A rare genetic blood disorder found in Navajo populations and characterized by a progressive skin disorder and neutropenia (lack of neutrophils which are needed to fight bacterial infections). Navajo poikiloderma is listed as a ""rare disease"" by the Office of Rare Diseases (ORD) of the National Institutes of Health (NIH). This means that Navajo poikiloderma, or a subtype of Navajo poikiloderma, affects less than 200,000 people in the US population. "

Naxos disease

Since 1995, according to the World Health Organisation’s classification of cardiomyopathies, Naxos disease has been considered as the recessive form of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C).1 It is a stereotype association of ARVD/C with a cutaneous phenotype, characterised by woolly hair and palmoplantar keratoderma.

Necrotizing enterocolitis

Necrotizing enterocolitis (NEC) is the most common GI medical/surgical emergency occurring in neonates. NEC represents a significant clinical problem and affects close to 10% of infants who weigh less than 1500 g, with mortality rates of 50% or more depending on severity. Although it is more common in premature infants, it can also be observed in term and near-term babies. Despite intensive study over the past 30 years, its etiology remains elusive

Necrotizing fasciitis

For more than a century, many authors have described soft tissue infections. Their occurrence has been on the rise because of an increase in immunocompromised patients with diabetes mellitus, cancer, alcoholism, vascular insufficiencies, organ transplants, HIV, or neutropenia. Necrotizing fasciitis can occur after trauma or around foreign bodies in surgical wounds, or it can be idiopathic, as in scrotal or penile necrotizing fasciitis. Necrotizing fasciitis has also been referred to as hemolytic streptococcal gangrene, Meleney ulcer, acute dermal gangrene, hospital gangrene, suppurative fascitis, and synergistic necrotizing cellulitis. Fournier gangrene is a form of necrotizing fasciitis that is localized to the scrotum and perineal area. Necrotizing fasciitis is a progressive, rapidly spreading, inflammatory infection located in the deep fascia, with secondary necrosis of the subcutaneous tissues. Because of the presence of gas-forming organisms, subcutaneous air is classically described in necrotizing fasciitis. This may be seen only on radiographs or not at all. The speed of spread is directly proportional to the thickness of the subcutaneous layer. Necrotizing fasciitis moves along the deep fascial plane. These infections can be difficult to recognize in their early stages, but they rapidly progress. They require aggressive treatment to combat the associated high morbidity and mortality. The causative bacteria may be aerobic, anaerobic, or mixed flora, and the expected clinical course varies from patient to patient.

Negative rheumatoid factor polyarthritis

A form of rheumatoid arthritis which doesn't involves the presence of rheumatoid factor in the blood. Negative rheumatoid factor polyarthritis is listed as a "rare disease" by the Office of Rare Diseases (ORD) of the National Institutes of Health (NIH). This means that Negative rheumatoid factor polyarthritis, or a subtype of Negative rheumatoid factor polyarthritis, affects less than 200,000 people in the US population

Neisseria meningitidis

, also simply known as meningococcus, is a heterotrophic gram-negative diplococcal bacterium best known for its role in meningitis[1] and other forms of meningococcal disease such as meningococcemia. N. meningitidis is a major cause of morbidity and mortality in childhood in industrialized countries and is responsible for epidemics in Africa and in Asia. Anton Weichselbaum in 1887 was first reported the disease from patients infected with meningococci [2]. It is known that meningococci only infects human and never been reported from animals because the bacterium cannot get iron other than human source (transferrin and lactoferrin)[3] and it exists as normal flora in the nasopharynx of up to 40% of adults. It causes the only form of bacterial meningitis known to cause epidemics. Meningococcus is spread through the exchange of saliva and other respiratory secretions during activities like coughing, kissing, and chewing on toys. Though it initially produces with general symptoms like fatigue, it can rapidly progress from fever, headache and neck stiffness to coma and death. Death occurs in approximately 10% of cases.[4] Those with impaired immunity may be at particular risk of meningococcus (e.g. those with nephrotic syndrome or splenectomy; vaccines are given in cases of removed or non-functioning spleens). Suspicion of meningitis is a medical emergency and immediate medical assessment is recommended. Current guidance in the United Kingdom is that any doctor who suspects a case of meningococcal meningitis or septicaemia (infection of the blood) should give intravenous antibiotics (benzylpenicillin or Cefotaxime) and admit the ill person to the hospital.[5] This means that laboratory tests may be less likely to confirm the presence of Neisseria meningitidis as the antibiotics will dramatically lower the number of bacteria in the body. The UK guidance is based on the idea that the reduced ability to identify the bacteria is outweighed by reduced chance of death.

Nelson syndrome

Nelson syndrome refers to a spectrum of symptoms and signs arising from an adrenocorticotropin (ACTH)–secreting pituitary macroadenoma after a therapeutic bilateral adrenalectomy. The spectrum of clinical features observed relates to the local effects of the tumor on surrounding structures, the secondary loss of other pituitary hormones, and the effects of the high alpha-melanocyte–stimulating hormone (a-MSH), another derivative of proopiomelanocortin (POMC, the precursor peptide from which ACTH is derived) on the skin. The first case was reported by Nelson et al in 1958.

Nemaline myopathy 1

A very rare inherited muscle disorder and is characterized by muscle weakness caused by the presence of nemaline rods in the muscle tissue which affects its function. There are at least 7 different subtypes of nemaline myopathy, each with a different genetic defect. The severity of the symptoms may vary greatly even among patients within a particular subtype of the disorder. Type 1 is caused by a defect on the tropomyosin 3 gene on chromosome 1q22.

Nemaline Myopathy 2

Nemaline myopathy 2: A very rare inherited muscle disorder and is characterized by muscle weakness caused by the presence of nemaline rods in the muscle tissue which affects its function. There are at least 7 different subtypes of nemaline myopathy, each with a different genetic defect. The severity of the symptoms may vary greatly even among patients within a particular subtype of the disorder. Type 2 is caused by a defect on the nebulin gene on chromosome 2q22.

Nemaline myopathy 3

Nemaline myopathy 3: A very rare inherited muscle disorder and is characterized by muscle weakness caused by the presence of nemaline rods in the muscle tissue which affects its function. There are at least 7 different subtypes of nemaline myopathy, each with a different genetic defect. The severity of the symptoms may vary greatly even among patients within a particular subtype of the disorder. Type 3 is caused by a defect on the alpha-actin gene.

Nemaline myopathy 4

Nemaline myopathy 4: A very rare inherited muscle disorder and is characterized by muscle weakness caused by the presence of nemaline rods in the muscle tissue which affects its function. There are at least 7 different subtypes of nemaline myopathy, each with a different genetic defect. The severity of the symptoms may vary greatly even among patients within a particular subtype of the disorder. Type 4 is caused by a defect on the tropomyosin 2 gene on chromosome 9p13

Nemaline myopathy 5

Nemaline myopathy 5: A very rare inherited muscle disorder and is characterized by muscle weakness caused by the presence of nemaline rods in the muscle tissue which affects its function. There are at least 7 different subtypes of nemaline myopathy, each with a different genetic defect. The severity of the symptoms may vary greatly even among patients within a particular subtype of the disorder. Type 5 is caused by a defect on the Troponin T1 gene on chromosome 19q13.4

Nemaline myopathy 6

Nemaline myopathy 6: A very rare inherited muscle disorder and is characterized by muscle weakness caused by the presence of nemaline rods in the muscle tissue which affects its function. There are at least 7 different subtypes of nemaline myopathy, each with a different genetic defect. The severity of the symptoms may vary greatly even among patients within a particular subtype of the disorder. Type 6 is caused by a defect on chromosome 15q. Type 4 was slowly progressive but wheelchair dependency does not eventuate.

NEMO mutation with immunodeficiency

NEMO mutation with immunodeficiency: A very rare form of immunodeficiency caused by a mutation of the NEMO (NF-kappa-B essential modulator) gene on chromosome Xq28. The immunodeficiency causes sufferers to develop pus-forming bacterial infections early in life and as they get older, they tend to become susceptible to mycobacterial infections.

Neonatal alloimmune thrombocytopenia

Neonatal alloimmune thrombocytopenia (NAITP, NAIT, NATP or NAT) is a disease that affects babies in which the platelet count is decreased. Platelet antigens are inherited from both mother and father. NAIT is caused by antibodies specific for platelet antigens inherited from the father but which are absent in the mother. Fetomaternal transfusions (or fetomaternal hemorrhage) results in the recognition of these antigens by the mother's immune system as non-self, with the subsequent generation of allo-reactive antibodies which cross the placenta. NAIT, hence, is caused by transplacental passage of maternal platelet-specific alloantibody and rarely human leukocyte antigen (HLA) allo-antibodies (which are expressed by platelets) to fetuses whose platelets express the corresponding antigens. NAIT occurs in somewhere between 1/800 and 1/5000 live births. More recent studies of NAIT seem to indicate that it occurs in around 1/600 live births in the Caucasian population.

Neonatal Hemochromatosis

Neonatal hemochromatosis is a syndrome in which severe liver disease of fetal or perinatal onset is associated with deposition of stainable iron in extrahepatic sites. The distribution of extrahepatic iron mimics that observed in hepatic iron (HFE) disease, the most common form of hemochromatosis known in Europe and the Americas, and liver disease is common in late-stage HFE disease. Nonetheless, neonatal hemochromatosis is not a manifestation of HFE disease. Neonatal hemochromatosis is not a single disorder but is a syndrome with an unclear etiology. Neonatal hemochromatosis represents disordered iron handling due to injury to the perinatal liver. Neonatal hemochromatosis can be thought of as a form of fulminant hepatic failure. Four pieces of evidence suggest that neonatal hemochromatosis may be due to an acquired and persistent maternal factor. (1) Neonatal hemochromatosis recurs within sibships at a rate higher than expected for disorders transmitted in an autosomal recessive manner. (2) Several kindreds are known in which mothers have given birth to children with neonatal hemochromatosis who were fathered by different men. (3) Several kindreds are known in which parents of children with neonatal hemochromatosis had histories of exposure to blood with or without clinical hepatitis. (4) Anecdotal evidence suggests that administering intravenous immunoglobulin during pregnancy in a woman who has already had an infant with neonatal hemochromatosis leads to a relatively favorable outcome. This data suggest mitochondrial disease; transplacental transmission of an infective, possibly viral, agent; or transplacental transmission of an antibody as a cause of at least some instances of neonatal hemochromatosis. Because neonatal hemochromatosis is a syndrome, any of these possibilities may be correct in a given family, and all of them must be considered. Treatment after birth requires supportive care with or without administration of an iron-chelating cocktail and several antioxidants. Liver transplantation has saved some babies. Liver disease ascribed to siderosis has not recurred in survivors to date.

Neonatal herpes

Neonatal herpes is the term used when a baby develops symptoms of herpes infection before he/she is born or within the first 6 weeks of life. It may occur when the baby is still in the womb (intra uterine/congenital infection) (

Neonatal jaundice hyperbilirubinemia

Neonatale jaundice hyperbilirubinemia(also known as Neonatal jaundice or neonatal hyperbilirubinemia, or neonatal icterus from the Greek word ἴκτερος), attributive adjective: icteric, is a yellowing of the skin and other tissues of a newborn infant. A bilirubin level of more than 85 μmol/l (5 mg/dL) leads to a jaundiced appearance in neonates whereas in adults a level of 34 μmol/l (2 mg/dL) is needed for this to occur. In newborns, jaundice is detected by blanching the skin with pressure applied by a finger so that it reveals underlying skin and subcutaneous tissue. Jaundiced newborns have yellow discoloration of the white part of the eye, and yellowing of the face, extending down onto the chest.

Neonatal jaundice can make the newborn sleepy and interfere with feeding. Extreme jaundice can cause permanent brain damage from kernicterus.
In neonates, the yellow discoloration of the skin is first noted in the face and as the bilirubin level rises proceeds caudal to the trunk and then to the extremities. This condition is common in newborns affecting over half (50–60%) of all babies in the first week of life.

Infants whose palms and soles are yellow, have serum bilirubin level over 255 μmol/l (15 mg/dL) (more serious level). Studies have shown that trained examiners assessment of levels of jaundice show moderate agreement with icterometer bilirubin measurements. In infants, jaundice can be measured using invasive or non-invasive methods.

Neonatal ovarian cyst

Neonatal ovarian cyst: A rare cyst that develops in the lower abdomen of a female fetus

Neonatal progeroid syndrome

Neonatal progeroid syndrome syndrome (Wiedeman-Rautenstrauch syndrome) is an extremely rare genetic disorder characterized by an aged appearance at birth (neonatal progeroid appearance); growth delays before and after birth (prenatal and postnatal growth retardation); and deficiency or absence of the layer of fat under the skin (subcutaneous lipoatrophy), causing the skin to appear abnormally thin, fragile, and wrinkled. In addition, for reasons that are not understood, abnormal deposits of fat may accumulate around the buttocks, the areas around the genitals and the anus (anogenital area), and the area between the ribs and the hips (flanks).

Neonatal Systemic lupus erythematosus

Neonatal lupus erythematosus (NLE) is a rare disorder caused by the transplacental passage of maternal autoantibodies. Only 1% of infants with positive maternal autoantibodies develop NLE. The most common clinical manifestations are cardiac, dermatologic, and hepatic. Some infants may also have hematologic abnormalities. Most mothers at the time of childbirth are healthy and without signs or symptoms of lupus erythematosus or other collagen vascular disorders. Mothers of children with NLE may later develop an atypical rather than classic picture of systemic lupus erythematosus (SLE) or other connective tissue disorder. If a mother with anti-Ro autoantibodies has 1 child with NLE, the incidence in subsequent pregnancies is approximately 25%. The incidence of congenital heart block is 15-30% in infants with NLE.