July 15, 2008
More than 60 years ago, Dr. Poul Fogh-Andersen published a comprehensive analysis of cleft lip and palate in his native Denmark. His landmark study led him and scientists to the present day to believe that cleft lip and palate, although often affecting newborns in tandem, are developmentally distinct. One could occur in isolation without the other, and the variations that Fogh-Andersen painstakingly documented in the mode of inheritance among families and the sexes seemed to bear this out. In the July 1 issue of the American Journal of Medical Genetics Part A, NIDCR grantees and colleagues ask whether the concept of isolated cleft palate needs to be revisited. Using high-resolution ultrasound, they report discovering retrospectively in four of 27 people born with an isolated cleft palate subtle to distinct breaks in their upper lip orbiculis oris muscle. As the authors noted, disruptions in the orbiculis oris muscle that are not visible to the eye but can be visualized on ultrasound have been hypothesized in recent years as representing the mildest manifestation of cleft lip, and have been observed in family members who are clinically considered unaffected. “Consequently, this raises the possibility that some portion of existing CP [isolated cleft palate] families may actually be mixed cleft or CL/P [cleft lip with or without cleft palate] families,” the authors concluded. “. . . Moreover, accurate phenotype definition is critical for the classification of cases prior to epidemiological and genetic analysis, since CP and CL/P families are believed to segregate different susceptibility genes.”
Read more about this paper by Weinberg, SM, Marazita, ML, et. al.