Orbicularis oris muscle defects as an expanded phenotypic feature in nonsyndromic cleft lip with or without cleft palate

Katherine Neiswanger, Seth M. Weinberg, Carolyn R. Rogers, Carla A. Brandon, Margaret E. Cooper, Kathleen M. Bardi, Frederic W.B. Deleyiannis, Judith M. Resick, A'Delbert Bowen, Mark P. Mooney, Javier Enríquez De Salamanca, Beatriz González, Brion S. Maher, Rick A. Martin, Mary L. Marazita

Research output: Contribution to journalArticlepeer-review

58 Scopus citations


Nonsyndromic cleft lip ± cleft palate is a complex disease with a wide phenotypic spectrum; occult defects of the superior orbicularis oris muscle may represent the mildest subclinical form of the lip portion of the phenotype. This study used high-resolution ultrasonography to compare the frequency of discontinuities in the OO muscle in 525 unaffected relatives of individuals with nonsyndromic cleft lip ± cleft palate versus 257 unaffected controls. OO muscle discontinuities were observed in 54 (10.3%) of the non-cleft relatives, compared to 15 (5.8%) of the controls - a statistically significant increase (P = 0.04). Male relatives had a significantly higher rate of discontinuities than male controls (12.0% vs. 3.2%; P = 0.01); female relatives also had a higher rate of discontinuities than female controls, but the increase was not statistically significant (8.9% vs. 7.4%; P = 0.56). These data confirm the hypothesis that subepithelial OO muscle defects are a mild manifestation of the cleft lip phenotype. Identification of subepithelial OO muscle defects may be important in a clinical setting, as a means of providing more accurate recurrence risk estimates to relatives in cleft families. Furthermore, the expansion of the cleft lip ± cleft palate phenotypic spectrum should improve the power of genetic studies.

Original languageEnglish (US)
Pages (from-to)1143-1149
Number of pages7
JournalAmerican Journal of Medical Genetics, Part A
Issue number11
StatePublished - Jun 1 2007
Externally publishedYes


  • Cleft lip
  • Cleft lip and palate
  • Orbicularis oris muscle
  • Phenotype
  • Unaffected relatives

ASJC Scopus subject areas

  • Genetics
  • Genetics(clinical)


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