Diseases

Neurosarcoidosis

Sarcoidosis is a multisystem disease process whose pathogenesis involves formation of an inflammatory lesion known as a granuloma. Most patients with sarcoidosis do not have any symptoms; the disease often is detected on routine chest radiograph. Symptoms, if present, include cough, shortness of breath, and arthritis. The lungs are affected most frequently, but the eyes, nervous system, heart, kidneys, bones, and joints also may be affected. Sarcoidosis is a disease of unknown etiology. Involvement of the central nervous system is referred to as neurosarcoidosis. Neurosarcoidosis is an uncommon but severe, sometimes life-threatening, manifestation of sarcoidosis. It generally occurs only if the disease has had substantial systemic involvement, and signs of neurologic involvement usually are seen in patients known to have active disease. Strictly neurologic forms are seen in fewer than 10% of patients.

Neurosyphilis

Syphilis bacteria frequently invade the nervous system during the early stages of infection, and approximately 3 to 7 percent of persons with untreated syphilis develop neurosyphilis. Some persons with neurosyphilis never develop any symptoms. Others may have headache, stiff neck, and fever that result from an inflammation of the lining of the brain. Some patients develop seizures. Patients whose blood vessels are affected may develop symptoms of stroke with resulting numbness, weakness, or visual complaints. In some instances, the time from infection to developing neurosyphilis may be up to 20 years. Neurosyphilis may be more difficult to treat and its course may be different in people with HIV infection

Neurotoxicity syndromes

Neurotoxicity syndromes: Altered nervous system functioning caused by exposure to certain chemicals (manmade or natural) that affect the nervous system - essentially it is the poisoning of the nervous system. Examples of toxic compounds that may cause neurotoxicity include lead, certain solvents and pesticides. Symptoms may occur immediately or gradually over a period of time. Neurotoxicity syndromes is listed as a "rare disease" by the Office of Rare Diseases (ORD) of the National Institutes of Health (NIH). This means that Neurotoxicity syndromes, or a subtype of Neurotoxicity syndromes, affects less than 200,000 people in the US population.

Neurotrophic Keratopathy

Neurotrophic keratopathy is a degenerative disease of the corneal epithelium resulting from impaired corneal innervation. A reduction in corneal sensitivity or complete corneal anesthesia is the hallmark of this disease and is responsible for producing epithelial keratopathy, ulceration and perforation. Although numerous ocular and systemic diseases may result in neurotrophic keratopathy, there is one common insult: a lesion of the trigeminal nerve (cranial nerve V) or its branches.

Patients with neurotrophic keratopathy should undergo a complete medical and surgical history, a review of medications and an ocular examination. Although the clinical diagnosis may be made without difficulty, the management of neurotrophic keratopathy can be quite challenging.

http://www.aao.org

Neutropenia intermittent

A blood disorder where the level of neutrophils in the blood fluctuates with periods of low neutrophil levels. Neutrophils are the body's first line of defense against infection and destroy bacteria in the blood. Low levels of neutrophils increases the risk of infection.

Neutropenia- severe chronic

A rare blood disorder where there are abnormally low levels of neutrophils (type of white blood cell) in the body which impairs the body's ability to fight bacterial infections. There are four main types of the disorder: idiopathic, congenital, autoimmune and cyclical

Neutrophilic dermatosis- acute febrile

Acute febrile neutrophilic dermatosis, also termed Sweet syndrome, is a reactive process characterized by the abrupt onset of tender, red-to-purple papules, and nodules that coalesce to form plaques. The plaques usually occur on the upper extremities, face, or neck and are typically accompanied by fever and peripheral neutrophilia. Initially described in 1964 by Robert Sweet, the entity currently recognized as Sweet syndrome ranges from classic Sweet disease, which occurs in young women after a mild respiratory illness, to a more aggressive neutrophilic process, which may be associated with other inflammatory diseases or malignancy. In fact, the lesions may be the first evidence of an underlying disorder and should prompt further investigation. A drug-induced variant due to the administration of various medications has been recognized, and a pregnancy-associated form has also been reported. In general, Sweet syndrome responds dramatically to oral corticosteroids and may improve or resolve with treatment of the underlying condition. Without treatment, the syndrome may persist for weeks or months and then improves without leaving scars. Recurrences are common. In rare cases, crops of lesions reappear and the condition persists indefinitely. Cases associated with malignancy can be bullous or ulcerative and resemble atypical pyoderma gangrenosum. These lesions are often recalcitrant to treatment. The diagnosis of Sweet syndrome is based on both clinical and histopathologic findings. Characteristics that distinguish the lesions of Sweet syndrome from other neutrophilic dermatosis are healing of the lesions without scarring and an absence of vasculitis.

Nevi flammei- familial multiple

A rare inherited condition involving the presence of dark red, flat patches of skin. The patches can occur anywhere on the body, they vary in size and there is more than one.

Nevo syndrome

Nevo syndrome (medical condition): A genetic disorder characterized by excessive fetal growth, loose joints, kyphosis and impaired speech and motor development

Nevoid basal cell carcinoma syndrome

Nevoid basal cell carcinoma syndrome (NBCCS, also known as basal cell carcinoma nevus syndrome, multiple basal cell carcinoma syndrome, Gorlin syndrome, and Gorlin–Goltz syndrome,and BCCNS), is an inherited medical condition involving defects within multiple body systems such as the skin, nervous system, eyes, endocrine system, and bones. People with this syndrome are particularly prone to developing a common and usually non-life-threatening form of non-melanoma skin cancer.

About 10% of people with the condition do not develop basal-cell carcinomas (BCCs). The name Gorlin syndrome refers to researcher Robert J. Gorlin (1923–2006).

First described in 1960, NBCCS is an autosomal dominant condition that can cause unusual facial appearances and a predisposition for basal-cell carcinoma, a type of skin cancer which rarely spreads to other parts of the body. The prevalence is reported to be 1 case per 56,000-164,000 population. Recent work in molecular genetics has shown NBCCS to be caused by mutations in the PTCH (Patched) gene found on chromosome arm 9q. If a child inherits the defective gene from either parent, he or she will have the disorder.

Nevus of ota retinitis pigmentosa

Nevus of ota retinitis pigmentosa: A very rare syndrome characterized by abnormal pigmentation of the eye and the skin surrounding the eye

Nevus sebaceus of Jadassohn

Nevus sebaceous of Jadassohn: A rare genetic neurocutaneous disorder characterized by epidermal nevi associated with central nervous and skeletal system abnormalities

NGLY1 deficiency

NGLY1 deficiency (or N-glycanase deficiency) is an extremely rare genetic disorder of the endoplasmic reticulum. It falls within the family of Congenital Disorders of Glycosylation (CDG). In this disorder, the cells of the body cannot synthesize the enzyme N-glycanase.  N-glycanase 1 (encoded by the gene NGLY1) is responsible for cleaving N-linked glycans from misfolded glycoproteins, so that the body can recycle them. Lacking N-glycanase leaves the body with an impaired capacity to recycle misfolded glycoproteins, which appear to accumulate in the cells of patients, and which is associated with neurological dysfunction, abnormal tear production, and liver disease. The majority of patients detected to date carry a specific nonsense mutation that appears to be associated with severe disease. The phenotypic spectrum is likely to enlarge as cases with a broader range of mutations are detected. 

N-glycanase deficiency is recessive: when parents are carriers, they have a 25% chance of producing a child with the disorder for each pregnancy.

 

Nguyen syndrome

Nguyen syndrome: A rare disorder characterized by low blood cholesterol, mental retardation and various congenital anomalies

Nicolaides–Baraitser syndrome

Nicolaides–Baraitser syndrome (NCBRS) is a rare genetic condition caused by de novo missense mutations in the SMARCA2 gene and has only been reported in less than 100 cases worldwide. NCBRS is a distinct condition and well recognizable once the symptoms have been identified.

Niemann-Pick Disease

Niemann–Pick disease is a group of inherited severe metabolic disorders in which sphingomyelin accumulates in lysosomes in cells. The lysosomes normally transport material through and out of the cell.

The prognosis is individual but the severe form is fatal in toddlerhood and the milder forms may even in some cases have a normal lifespan.

This disease involves dysfunctional metabolism of sphingolipids, which are fats found in cell membranes, so it is a kind of sphingolipidosis. Sphingolipidoses, in turn, are included in the larger family of lysosomal storage diseases.

Niemann-Pick Disease Type C

Niemann-Pick disease (NPC) is an inherited metabolic disorder where lipids are not able to be metabolized adequately and hence build up and cause damage in various parts of the body such as the spleen, liver, lungs, bone marrow and brain. The different types of the disease are due to different genetic mutations.

There are four most commonly recognized forms of the disease: Types A, B, C, and D. Types A and B are also called Type I. Types C and D are also known as Type II.

Type C is a juvenile or subacute form of the condition which usually starts during childhood and survival into adulthood is possible.

Niemann-Pick Disease Type D

Niemann-Pick disease is an inherited metabolic disorder where lipids are not able to be metabolized adequately and hence build up and cause damage in various parts of the body such as the spleen, liver, lungs, bone marrow and brain.

Type D Niemann-Pick involves a defect that interferes with the movement of cholesterol between brain cells. It is now thought to be a variant of type C. This type of Niemann-Pick disease has only been found in the French Canadian population of Yarmouth County, Nova Scotia.

Symptoms, diagnosis, prevention and treatment are the same as with Type C. Please see our Niemann-Pick Disease page for more Information.

Nievergelt syndrome

Nievergelt syndrome: A rare inherited bone disease which causes abnormalities in the lower leg and lower arm bones as well as dwarfism and digit anomalies

Night blindness- congenital stationary

Night blindness, congenital stationary, type 1A: A rare X-linked disorder of the retina that involves the rods of the eyes. A reduced sharpness of vision and night blindness are usually the only symptoms. The non-progressive disorder is linked to a defect at chromosome Xp11.4 and occurs only in males though females may be carriers

Nijmegen Breakage Syndrome

Nijmegen breakage syndrome (NBS) is a rare autosomal recessive condition of chromosomal instability that is clinically characterized by microcephaly, a distinct facial appearance, short stature, immunodeficiency, radiation sensitivity, and a strong predisposition to lymphoid malignancy. Mutations in the NBS1 gene located in band 8q21 are responsible for NBS. NBS is identified as entries 251260 in and 602667 in Online Mendelian Inheritance in Man. In 1981, Weemaes et al1 first delineated the syndrome in 2 siblings with microcephaly, short stature, skin pigmentation abnormalities, mental retardation, immunologic defects, and a high prevalence of chromosome 7 and/or chromosome 14 rearrangements in cultured lymphocytes. In 1985, Seemanova et al2 described a group of patients with an apparently new genetic disorder characterized by microcephaly with normal intelligence, cellular and humoral immune defects, and a striking predisposition to lymphoreticular malignancies. These cases were subsequently studied and found to fit into the category of NBS. Further investigations revealed that in vitro cells derived from patients with NBS display characteristic abnormalities similar to those observed in ataxia-telangiectasia (A-T), including spontaneous chromosomal instability, sensitivity to ionizing radiation (IR), and radioresistant DNA synthesis (RDS). However, aside from immune deficiency and a predisposition for malignancies (particularly those of lymphoid origin), the clinical manifestations are distinct. Consequently, NBS has long been considered a variant of A-T. In 1998, on the basis of cellular phenotypes and the results of somatic cell complementation studies suggesting genetic heterogeneity, Jaspers et al proposed the term A-T variants for diseases in this group of patients. The 2 distinct groups were designated as A-T variant 1 (V1) for NBS and A-T variant 2 (V2) for Berlin breakage syndrome. Linkage studies allowed the exclusion of the gene responsible for NBS from the A-T locus on band 11q23 and from the translocation breakpoints in a Polish patient. When 2 independent groups of researchers finally mapped the gene to band 8q21 and isolated it in 1998, mutations in the single NBS1 gene were found to account for both A-T complementation groups V1 and V2.

Nipah virus encephalitis

Nipah virus encephalitis: Inflammation of the brain caused by the Nipah virus which can infect pigs and humans so transmission usually occurs through contact with pigs.

Nivelon Nivelon Mabille syndrome

Nivelon-Nivelon-Mabille syndrome: A very rare syndrome characterized mainly by severe dwarfism, abnormal bone development and central nervous system and eye problems

Nocardiosis

Nocardiosis is an infection caused by bacteria (Nocardia) which live in the soil. If inhaled, the bacteria may cause pneumonia, which can lead to blood poisoning (sepsis) and the spread of nocardiosis to other organs of the body. This is called disseminated nocardiosis. People with compromised immune systems, such as people with cancer or those taking steroids or immunosuppressive medications, are at risk for disseminated nocardiosis. Nocardia may also infect the skin through a cut, puncture wound, or scratch that occurs while working outdoors or gardening. The skin infections, which may take different forms, are called cutaneous nocardiosis. Occupational exposure to soil, as in field work, landscaping, and farming, increases the risk of contracting cutaneous nocardiosis

Nodular melanoma

Nodular melanoma (NM) is the most aggressive form of melanoma. It grows in vertical direction from the outset and grows very fast (months). Nodular melanoma has no known precursor. It is a small black, or if amelanotic, pink nodule that simply enlarges. The lesions tend to bleed. The microscopic hallmarks are:

• Dome-shaped at low power

• Epidermis thin or normal

• Dermal nodule of melanocytes with a “pushing” growth pattern

• No "radial growth phase"