X-linked nephrogenic diabetes insipidus

DEFINITION:

A form of diabetes insipidus, inherited as an X-linked trait, caused by failure of the renal tubules to reabsorb water in response to antidiuretic hormone, without disturbance in the renal filtration and solute excretion rates; the condition does not respond to exogenous vasopressin.

NDI

DEFINITION:

Nephrogenic diabetes insipidus.

inherited disorder

DEFINITION:

A derangement or abnormality of function or a morbid physical or mental state acquired by transmission from parent to offspring.

characterized

DEFINITION:

Marked or distinguished as a characteristic.

urine

DEFINITION:

The fluid excreted by the kidneys, passed through the ureters, stored in the bladder, and discharged through the urethra. Urine, in health, has an amber color, a slight acid reaction, a peculiar odor, and a bitter, saline taste.

mutations

DEFINITION:

1. Changes in form, quality, or some other characteristic.

V2 vasopressin receptor

DEFINITION:

The molecular structure within a cell or on the surface to which the antidiuretic hormone, arginine vasopressin binds.

AVPR2

DEFINITION:

Arginine-vasopressin receptor 2 gene.

gene

DEFINITION:

A segment of a DNA molecule that contains all the information required for synthesis of a product (polypeptide chain or RNA molecule), including both coding and non-coding sequences. It is the biological unit of heredity, self-reproducing, and transmitted from parent to progeny. Each gene has a specific position (locus) on the chromosome map. From the standpoint of function, genes are conceived of as structural, operator, and regulatory genes.

wild-type gene - The normal allele of a gene, sometimes symbolized by +.

X-linked gene - A gene carried on the X chromosome; the corresponding trait, whether dominant or recessive, is always expressed in males, who have only one X chromosome. X linkage is used sometimes synonymously with sex linkage since no genetic disorders have as yet been associated with genes on the Y chromosome.

NDI

DEFINITION:

Nephrogenic diabetes insipidus.

mutations

DEFINITION:

1. Changes in form, quality, or some other characteristic.

AVPR2 gene

DEFINITION:

Arginine-vasopressin receptor 2 gene.

novel

DEFINITION:

Of a new kind, or different from anything seen or known before.

mutations

DEFINITION:

1. Changes in form, quality, or some other characteristic.

missense

DEFINITION:

Genetic mutation involving alteration of one or more codons so that different amino acids are determined.

mutation

DEFINITION:

1. A change in form, quality, or some other characteristic.

2. In genetics, a permanent transmissible change in the genetic material, usually in a single gene.

frameshift mutation - A mutation resulting from an addition or subtraction that is not an exact multiple of 3 base pairs in a coding sequence. From the point of mutation onwards, base triplets (codons) are read out of phase; the reading frame of the gene is changed, and a completely different set of amino acids is made into protein.

loss-of-function mutation - Impairment of the function of a gene caused by mutation.

missense mutation - A mutation that changes a codon so that it codes for a different amino acid.

nonsense mutation - A mutation in which one of the three terminator codons in the mRNA (UAG, amber; UAA, ochre; UGA, umber or opal), used to signal the end of a polypeptide, appears in the middle of a genetic message, causes premature termination of transcription, and releases incomplete, generally nonfunctional polypeptides from the ribosome.

point mutation - A mutation resulting from a change in a single base pair in the DNA molecule, caused by the substitution of one nucleotide for another.

aquaporin-2 gene

DEFINITION:

The segment of a DNA molecule that contains all the information required for synthesis of aquaporin-2.

autosomal recessive NDI

DEFINITION:

See autosomal recessive nephrogenic diabetes insipidus.

NDI

DEFINITION:

Nephrogenic diabetes insipidus.

in vitro

DEFINITION:

Within a glass; observable in a test tube; in an artificial environment.

functional analysis

DEFINITION:

Determining the function or characteristic behaviors of component parts of a substance.

agonist

DEFINITION:

1. In anatomy, a prime mover.

2. In pharmacology, a drug that has affinity for and stimulateS physiologic activity at cell receptors normally stimulated by naturally occurring substances.

cAMP

DEFINITION:

Cyclic AMP (cyclic adenosine monophosphate).

cell surface

DEFINITION:

See plasma membrane.

mutation

DEFINITION:

1. A change in form, quality, or some other characteristic.

2. In genetics, a permanent transmissible change in the genetic material, usually in a single gene.

frameshift mutation - A mutation resulting from an addition or subtraction that is not an exact multiple of 3 base pairs in a coding sequence. From the point of mutation onwards, base triplets (codons) are read out of phase; the reading frame of the gene is changed, and a completely different set of amino acids is made into protein.

loss-of-function mutation - Impairment of the function of a gene caused by mutation.

missense mutation - A mutation that changes a codon so that it codes for a different amino acid.

nonsense mutation - A mutation in which one of the three terminator codons in the mRNA (UAG, amber; UAA, ochre; UGA, umber or opal), used to signal the end of a polypeptide, appears in the middle of a genetic message, causes premature termination of transcription, and releases incomplete, generally nonfunctional polypeptides from the ribosome.

point mutation - A mutation resulting from a change in a single base pair in the DNA molecule, caused by the substitution of one nucleotide for another.

cell surface

DEFINITION:

See plasma membrane.

cAMP

DEFINITION:

Cyclic AMP (cyclic adenosine monophosphate).

ligand binding

DEFINITION:

See "ligand."

concentration

DEFINITION:

1. Increase in strength by evaporation.

2. The ratio of the mass or volume of a solute to the mass or volume of the solution or solvent.

vasopressin

DEFINITION:

1. One of two octapeptide hormones formed by the neuronal cells of the hypothalamic nuclei and stored in the posterior lobe of the pituitary gland (neurohypophysis), the other being oxytocin. It stimulates the contraction of the muscular tissue of the capillaries and arterioles, raising the blood pressure. It promotes contraction of the intestinal musculature and increases peristalsis, and also exerts some contractile influence on the uterus. It also has a specific effect on the epithelial cells of the distal portion of the uriniferous tubule, augmenting resorption of water independently of solutes, resulting in concentration of urine and dilution of blood serum. Its rate of secretion is regulated chiefly by the osmolarity of the plasma.

2. [USP], A pharmaceutical preparation of the same principle, prepared synthetically or obtained from the posterior pituitary of healthy domestic animals used for food by man; used mainly as an antidiuretic in the treatment of acute or chronic diabetes insipidus, administered intramuscularly as a test of hypothalamo-neurohypophysial-renal function in distinguishing central from nephrogenic diabetes insipidus; it may also be used to stimulate smooth muscle tissue, especially to induce vasoconstriction in the presence of hemorrhage. Called also antidiuretic hormone (ADH).

concentrations

DEFINITION:

1. Increases in strength by evaporation.

2. The ratios of the mass or volume of a solute to the mass or volume of the solution or solvent.

extracellularly

DEFINITION:

Occurring or pertaining to outside a cell or cells.

conserved

DEFINITION:

Kept from loss, decay, waste, or injury; preserved.

receptor

DEFINITION:

1. A molecular structure within a cell or on the surface characterized by (1) selective binding of a specific substance and (2) a specific physiologic effect that accompanies the binding, e.g., membrane receptors for peptide hormones, neurotransmitters, antigens, complement fragments, and immunoglobulins and nuclear receptors for steroid hormones.

2. A sensory nerve terminal that responds to stimuli of various kinds; classified in various ways including by the type of stimulus and by the location in the body.

V2 receptor - The structure to which the antidiuretic hormone, arginine vasopressin binds.

functional analysis

DEFINITION:

Determining the function or characteristic behaviors of component parts of a substance.

residue

DEFINITION:

1. A remainder; that which remains after the removal of other substances.
2. In biochemistry, the portion of a molecule that remains after it has lost some of its components, as an amino acid residue, which loses a water molecule when it is joined to another amino acid.

affinity

DEFINITION:

1. A special attraction for a specific element, organ, or structure.

2. Chemical affinity.

3. In immunology, a thermodynamic expression of the strength of interaction between a single antigen-binding site and a single antigenic determinant (and thus of the stereochemical compatibility between them), most accurately applied to interactions among simple, uniform antigenic determinants such as haptens. Expressed as the association constant (K liters mole^-1), which, owing to the heterogeneity of affinities in a population of antibody molecules of a given specificity, actually represents an average value (mean intrinsic association constant).

permission

DEFINITION:

Formal consent; authorization.