Indiana University-Purdue University Indianapolis (IUPUI) / Isolated cleft palate is one of the most frequent congenital conditions that affect
the oral and facial structures, yet its etiology remains obscure. Previous studies of both
cleft palate (CP) and cleft lip and/ or palate [CL(P)] have shown that there may be
unusual facial characteristics among the parents of such sporadic cases. Such findings
have been used to support the possibility that there are predisposing familial (genetic)
factors for both conditions. However, previous studies have generally not controlled for
the possibility of genetic heterogeneity or for different contributions from each of the
parents. The objective of this study is to examine parents of individuals with CP in order
to test the hypothesis that these "non cleft" individuals have abnormal facial structures.
Lateral (LA) and Posterior-Anterior (PA) cephalograms were examined from thirty
parents of fifteen individuals with sporadic CP. Seventeen LA and twenty-five PA
variables were obtained on each subject and converted to standardized "z-scores" through
comparison to published age and sex matched reference data. Multivariate cluster
analysis was used to define groupings of individuals who shared similar patterns of facial
features. Results demonstrate that as a group, relatives of CP individuals show
significantly different patterns of facial measurements compared to reference norms.
Values significantly larger (p < 0.05) fro1n parental data included: ANS-Me, PNS-ANS,
S-N-Pg, Ar-Go-Me, MoL-MoR, NSR-NCR. Values significantly smaller (p < 0.05) from
parents included: N-ANS, S-Ba, PNS-ANS/ N-ANS, PNS-ANS/ N-Pg, N-S-Ba, ZyL-ZyR,
GoL-GoR, GoNL-GoNR, CRO-CNS, CNS-SD, CNS-Me, ID-Me, MxR-ZyR, Me-GoR.
These findings were not entirely consistent with those few previously reported
findings. Additional analysis of the present data demonstrated that such inconsistencies
may be due in part to the presence of distinct phenotypic sub groupings within the
parental sample. Cluster analysis identified two such subgroups. Significant findings
(p < 0.05) that were smaller for Cluster 1 relative to Cluster 2 included: N-Me, ANS-Me,
S-Go, PNS-ANS, Ar-Go, CNS-SD, MxR-ZyR. Significant variables that were larger for
Cluster 1 included: S-N-Pg. In addition, gender was significantly different across
clusters with Cluster 1 containing 75 percent female individuals and Cluster 2 containing
67 percent male individuals. These results extend those reported in other studies by
demonstrating that unusual facial patterns, when present are not uniformly distributed in
parents of sporadic cases of CP. Phenotypic assessment in conjunction with multivariate
analysis may help to identify families in which there is a significant heritable component
for CP.
| Identifer | oai:union.ndltd.org:IUPUI/oai:scholarworks.iupui.edu:1805/4184 |
| Date | January 1999 |
| Creators | Sammons, Edward M. |
| Contributors | Ward, Richard E., Avery, David R., Hathaway, Ronald R., Garetto, Lawrence P., Hartsfield, James K., Jr. |
| Source Sets | Indiana University-Purdue University Indianapolis |
| Language | en_US |
| Detected Language | English |
| Type | Thesis |
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