The genetic variable most commonly studied is a single nucleotide polymorphism (SNP, pronounced "snip"); this is a DNA sequence variation that occurs when a single nucleotide (adenine, thymine, cytosine, or guanine) in the genome sequence is altered (a base pair change) and the particular alteration is present in at least 1% of the population.
SNPs are not clearly deleterious like mutations, which occur less frequently and generally hurt protein function.
SNPs are the most common gene variant in the population.
SNPs are a type of single-gene disorder; however, single-gene disorders can include other types of DNA sequence variations.

Although nurse practitioners are expected to know these diagnostic codes, it is not expected that they memorize them but rather that they use up-to-date resources for accuracy in diagnosis coding.
Nurse practitioner core competencies include the following:
* Scientific foundations
* Leadership
* Quality
* Practice inquiry
* Technology and information literacy
* Policy
* Health delivery systems
* Ethics
* Independent practice

Ziprasidone, olanzapine, quetiapine, and risperidone are all atypical antipsychotics. Ziprasidone is the least likely to cause weight gain and has been shown to lower triglyceride levels. For patients at an increased risk for developing metabolic syndrome, ziprasidone is the antipsychotic of choice.

Patients diagnosed with borderline personality disorder often develop transferences themselves and elicit countertransferences from others. This can greatly impede psychotherapeutic treatment. Group therapy combined with individual therapy benefits these patients by diluting the effects of both transference and countertransference.

Pica is a psychiatric condition occurring when a patient eats material that is not food, such as soap, chalk, plaster, or paper.
Enuresis refers to the repeated voiding of urine (either voluntarily or involuntarily) into bedding or clothing when five years old or older. Selective mutism is when a child chooses not to talk except when alone or with select friends or family. Rumination disorder is characterized by a persistent regurgitation and chewing of food already eaten.