Alleles for a particular phenotype determine what characteristic an organism will express, as with the following example where. 1  Chromosome 1 contains an allele for blonde hair. 2  Chromosome 2 contains an allele for brown hair. 3  Chromosome 3 contains an allele for blue eyes. 4  Chromosome 4 contains an allele for brown eyes.
Because of the patient's smoking history and abnormal chest radiograph, a neoplasm was initially suspected as a cause of SIADH. The head trauma was too remote to be of concern. Although 1 case of risperidone-associated hyponatremia has been reported, the risk seems low with this agent and with olanzapine.
Hypervolemic hyponatremia. Hypervolemic hyponatremia is characterized by an increase in both total body sodium (and thus ECF volume) and TBW with a relatively greater increase in TBW. Various edematous disorders, including heart failure and cirrhosis, cause hypervolemic hyponatremia. Rarely, hyponatremia occurs in nephrotic syndrome, although pseudohyponatremia may be due to interference with sodium measurement by elevated lipids.