Leslie Elizabeth J, Carlson Jenna C, Cooper Margaret E, Christensen Kaare, Weinberg Seth M, Marazita Mary L
Cleft Palate Craniofac J. 2017 Jan;54(1):90-93. doi: 10.1597/15-190. Epub 2016 Feb 16.
Monozygotic twins of an individual with an orofacial cleft have a significantly elevated risk for orofacial cleft compared with the general population, but still the concordance rate for orofacial cleft in monozygotic twins is about 40% to 50%. The goal of this study was to determine whether unaffected cotwins have an increased frequency of orbicularis oris muscle defects, a subclinical form of orofacial cleft. The presence of such defects may reduce the overall rate of discordance.
A total of 63 discordant monozygotic and dizygotic twin pairs, 262 unaffected nontwin siblings, and 543 controls with no history of orofacial clefts were assessed for orbicularis oris defects by high-resolution ultrasound. Frequencies were compared by the Fisher exact test.
Unaffected cotwins from discordant monozygotic pairs had a higher frequency of defects (12.5%) than the other test groups (6.38% to 6.99%), but the difference was not statistically significant (P = .74).
In this study, orbicularis oris defects were not statistically significantly more common among the unaffected twins from orofacial cleft discordant twin pairs. The trends in the results warrant future studies with larger sample sizes and additional subclinical phenotypes.
与普通人群相比，患有口面部裂隙个体的同卵双胞胎患口面部裂隙的风险显著升高，但同卵双胞胎中口面部裂隙的一致率仍约为40%至50%。本研究的目的是确定未受影响的双胞胎是否存在口轮匝肌缺陷的频率增加，这是口面部裂隙的一种亚临床形式。此类缺陷的存在可能会降低不一致的总体发生率。
通过高分辨率超声对总共63对不一致的同卵和异卵双胞胎、262名未受影响的非双胞胎兄弟姐妹以及543名无口面部裂隙病史的对照者进行口轮匝肌缺陷评估。采用Fisher精确检验比较频率。
不一致的同卵双胞胎中未受影响的双胞胎出现缺陷的频率（12.5%）高于其他测试组（6.38%至6.99%），但差异无统计学意义（P = 0.74）。
在本研究中，口轮匝肌缺陷在口面部裂隙不一致的双胞胎中未受影响的双胞胎中在统计学上并非显著更常见。结果趋势值得未来进行更大样本量以及更多亚临床表型的研究。
