Extensions to quantitative trait locus mapping in experimental organisms.

Quantitative trait locus (QTL) mapping studies involving inbred model organisms have become important and often-used investigative tools in contemporary genetics research. As a result, a number of statistical methods and study designs have been developed that have made it relatively easy for researchers to determine the rough locations of a number of QTLs that influence traits of all types, including a great many of relevance to hypertension and blood pressure regulation. However, as a whole, these methods and designs are limited in that they are not flexible enough to accommodate many of the complexities associated with quantitative trait expression. In this review, we describe a number of extensions to QTL mapping designs that should make QTL mapping experiments more insightful and compelling. These extensions include multiple QTL modeling with an emphasis on epistatic locus interaction and additive locus effects, the use of multiple phenotypic end points, the design of pharmacogenetic studies, the use of whole-genome parameters in quantitative trait investigations, and issues in mapping QTLs that influence traits that exhibit developmental trends. We use studies investigating the genetic basis of blood pressure regulation to exemplify relevant issues.

Severe rhinorrhea and respiratory distress in a neonate exposed to fluphenazine hydrochloride prenatally.

OBJECTIVE: To report a case of respiratory distress with severe rhinorrhea in a newborn exposed prenatally to fluphenazine hydrochloride. CASE SUMMARY: The safety of phenothiazines during pregnancy and the effect on the fetus and newborn are not well known. We describe a newborn who had severe rhinorrhea, vomiting, and respiratory distress after being exposed in utero to fluphenazine hydrochloride. Sepsis, choanal atresia, and congenital syphilis were excluded as causative factors for rhinorrhea. The rhinorrhea and upper airway obstruction responded to treatment with pseudoephedrine. CONCLUSIONS: Severe rhinorrhea, vomiting, and respiratory distress that occurred in this infant have not been reported previously following prenatal fluphenazine hydrochloride exposure. Awareness of this problem would be helpful to clinicians and should be considered in the differential diagnosis of rhinorrhea in newborns.