PURPOSE: Cleft lip with or without cleft palate (CLP) is a common birth defect, with phenotypes ranging from overt clefts to minimal microforms. Occult defects of the superior orbicularis oris (OO) muscle appear to be a part of this phenotypic spectrum. Analysis of the OO phenotype as a clinical tool is hypothesized to improve recurrence risk estimates in families.
METHODS: Upper lip ultrasound images were collected as a component of the Oral-Facial Cleft (OFC) study. Breaks in the continuity of the OO muscle visualized on ultrasound were scored as OO defects. Occurrences of CLP were compared between families with ≥ 1 family member with an OO defect and families without OO defects. Recurrence risks of CLP and of OO muscle defects among siblings and first degree relatives (FDRs) of probands with CLP were calculated using empiric proportions. Similar methods were used to calculate the recurrence risks of CLP and of OO defects among siblings and FDRs of probands with isolated OO defects.
RESULTS: The occurrences of CLP in families with and without a history of OO defects are 0.1863 and 0.1165, respectively (p < 0.01, OR = 1.735). The sibling recurrence risk of CLP in this cohort is 9.1%; the FDR risk is 15.7%, which are both significantly different from published CLP recurrence risk data. The likelihoods of one or more siblings or FDRs of a proband with CLP to have an OO defect are 14.7% and 11.4%, respectively. The sibling recurrence of isolated OO muscle defects in this cohort is 17.2%; the FDR recurrence is 16.4%. The chances for one or more siblings or FDRs of a proband with an OO defect to have a CLP are 3.3% and 7.3%, respectively, which are similar to the published recurrence risk estimates of nonsyndromic (NS) CLP.
CONCLUSIONS: This study supports OO muscle defects as being part of the CLP spectrum and suggests an improvement in the accuracy of recurrence risk estimates of CLP. Carefully defining the CLP phenotype has considerable public health relevance, as it is a critical component to the enhancement of genetic studies investigating the etiology of CLP.
| Identifer | oai:union.ndltd.org:PITT/oai:PITTETD:etd-04072009-123550 |
| Date | 29 June 2009 |
| Creators | Klotz, Cherise Maleyna |
| Contributors | Robin E. Grubs, Mary L. Marazita, Bernard J. Costello |
| Publisher | University of Pittsburgh |
| Source Sets | University of Pittsburgh |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.pitt.edu/ETD/available/etd-04072009-123550/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Pittsburgh or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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