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.
Polydipsia, muscle cramps, headaches, falls, confusion, altered mental status, obtundation, coma, and status epilepticus may indicate the need for acute intervention. Most patients with hyponatremia are asymptomatic, and hyponatremia is noted incidentally. Volume status should be assessed to help determine the underlying cause11, 13 (Figure 1 11 â 16[ corrected]).