Category: N

Neurocutaneous melanosis (NM) is a rare congenital syndrome characterized by the presence of multiple or large melanocytic nevi (moles or birthmarks) in association with benign or malignant pigment cell tumors of the leptomeninges (pia mater and arachnoid mater). A rare disorder marked by the presence of multiple or large pigmented nevi on the skin and…

Neuroacanthocytosis (NA), also known as Levine- Critchley syndrome, is a rare neurological disease associated with malformed red blood cells (also known as acanthocytes). Historically, NA has also been referred to as familial amyotrophic chorea with acanthocytosis or chorea- acanthocytosis, each referring to the common motor symptoms: chorea of the limbs, mouth, and tongue as well…

Neu-Laxova syndrome (NLS) is a rare, hereditable disorder of brain formation. Associated anomalies of the face, skin, extremities, and eyes are also common.  

Nail-patella syndrome (NPS) is a rare genetic disorder of connective tissue. The most frequently affected organs are nails, bone, eye, and kidney.  

All of the myopathies are associated with muscle weakness and lack of muscle tone (dystonia). Nemaline myopathy is differentiated from other myopathies by the presence of rod-shaped inclusion bodies or nemaline rods in the skeletal muscles; there is also a higher than normal preponderance of slow muscle tissue. Nemaline myopathy is evident from birth or…

Netherton syndrome (NS) is a rare, congenital, hereditary disorder characterized by ichthyosis (an abnormality of skin development that manifests as scaling and redness), several distinct anomalies of hair, and a tendency toward a variety of allergic illnesses. Skin findings are usually evident within two weeks after birth.  

Nonketotic hyperglycinemia (NKH) is a rare autosomal- recessive trait involving an error of glycine metabolism. Large amounts of the amino acid glycine accumulate in the body fluids, particularly in the cerebrospinal fluid. Two subtypes of this disorder exist: nonclassic NKH and neonatal NKH. The former appears later in life and presents with milder neurological deficits…

Nonessential nutrients are substances often provided in the diet of humans that can be produced in adequate amounts within the body to meet our needs for normal growth, development, and maintenance. Dietary intake of a nonessential nutrient will decrease the demand for its production.  

The content of essential nutrients as assessed in an analytical laboratory. The nutrient content of many foods humans consume can be found in the Tables of Composition compiled by the U.S.  

Measurement of indicators of dietary status and nutrition-related health status of individuals or populations.