Running Head: CLEFT LIP Nicole McLean RN Cleft Lip Drexel University

Abstract

Cleft Lip is one of the most common craniofacial abnormalities seen in children. Despite the prevalence of this condition concise identification of the pathophysiology and genes involved in the development of the condition remain an enigma. In an effort to provide a better understanding of the condition and the challenges that exists for genetic testing and intervention the current investigation provides an overview of cleft lip focusing on pathophysiology and interventions for medical and nursing care.

Cleft Lip Craniofacial abnormalities including cleft lip and cleft palate are among the most common human birth defects reported worldwide. Statistics indicate that these abnormalities are reported in 1 of every 700 live births with Asians and American Indians reporting the highest frequencies, often 1 in 500 live births (Murray, 2002). Although genetics have been implicated in the development of cleft lip, the etiology of the condition is highly complex (Yu, Serrano, San Miguel, Ruest & Svoboda, 2009). In an effort to provide a more integral understanding of this cleft lip the current investigation examines the pathophysiology of the condition, the risk factors of cleft lip, presenting symptoms, current treatment, discoveries and beliefs about the disease and patient teaching topics regarding genetic counseling for patients with this condition. The pathophysiology of cleft lip has been shown to be complex. While some cases of the condition are considered to be “nonsyndromic”, meaning that they are not related to any causal mechanism or malformative pattern, other cases are syndromic and can be traced to chromosomal and environmental factors (Ferrero, et al., 2009). As such the pathophysiology of nonsydromic cases often is viewed as multifactorial including the interaction of genetics and the environment in a process that is not currently well understood (Ferrero, et al., 2009). The pathophysiology of syndromic cases, on the other hand, is easier to trace to particular genomic sequences; however variability in outcomes continue to be reported (Ferrero, et al., 2009). Normal embryonic plate development begins in the fetus at about six weeks gestation (Yu, et al., 2009). Palatal shelves are differentiated by oral, nasal, and medial edges, which initially grow vertically aligning with the sides of the tongue. Once this growth is complete, the shelves begin developing laterally to produce a downward shift toward the mandible (Yu, et al., 2009). When cleft lip develops, one of five different palatal shelf defects can occur. These include: failure of the palatal shelf to form; fusion of the palatal shelf with structures such as the mandible or tongue; failure of the palatal shelf to elevate; failure of the palatal shelves to meet following elevation; and presence of the middle edge epithelium which impacts palate formation (Yu, et al., 2009). These defects can arise in any stage of ossification of the palate. In this process shelf movements must occur together with the tongue, mandible and head. Disruption can occur as a result of genetics, environment or a combination of the two producing one of the five defects which causes cleft lip (Yu, et al., 2009). The risk of inheriting cleft lip remains difficult to predict based on gene studies. Krapels, Vermeij-Keers, Muller, de Klein and Steegers- Theunissen (2006) argue that several different genes have been linked to cleft lip; however, these genes do not definitively predict whether or not a child will be born with this condition. Given the variability that exists in gene expression for cleft lip, Krapels and coworkers assert that the condition is best thought of as having a strong environmental component, which will have notable implications for