Novel insertion mutation in the PVRL1 gene in Turkish patients with non-syndromic cleft lip with/without cleft palate

Closing the Gap: Mouse Models to Study Adhesion in Secondary Palatogenesis

Secondary palatogenesis occurs when the bilateral palatal shelves (PS), arising from maxillary prominences, fuse at the midline, forming the hard and soft palate. This embryonic phenomenon involves a complex array of morphogenetic events that require coordinated proliferation, apoptosis, migration, and adhesion in the PS epithelia and underlying mesenchyme. When the delicate process of craniofacial morphogenesis is disrupted, the result is orofacial clefting, including cleft lip and cleft palate (CL/P). Through human genetic and animal studies, there are now hundreds of known genetic alternations associated with orofacial clefts; so, it is not surprising that CL/P is among the most common of all birth defects. In recent years, in vitro cell-based assays, ex vivo palate cultures, and genetically engineered animal models have advanced our understanding of the developmental and cell biological pathways that contribute to palate closure. This is particularly true for the areas of PS patterning and growth as well as medial epithelial seam dissolution during palatal fusion. Here, we focus on epithelial cell-cell adhesion, a critical but understudied process in secondary palatogenesis, and provide a review of the available tools and mouse models to better understand this phenomenon.

Identification of Novel Variants in the PVRL1 Gene in Patients With Nonsyndromic Cleft Lip With or Without Cleft Palate

OBJECTIVE

Nonsyndromic cleft lip with/without cleft palate (nsCL/P, OMIM 119530) is one of the most common birth defects with a prevalence of ∼1/1000 in Caucasians. Studies have demonstrated an association between nsCL/P and the variants of the poliovirus receptor like-1 gene (PVRL1). The aim of this study was to describe novel variants in exon 3 of the PVRL1 gene and to investigate the association between exon 3 of the PVRL1 gene and Turkish patients with nsCL/P.

METHODS

205 Turkish subjects were enrolled: 80 nsCL/P patients and 125 unrelated control individuals. Genomic DNA was isolated from peripheral blood leukocytes, and exon 3 of the PVRL1 gene was amplified using polymerase chain reaction (PCR). After PCR, the amplied DNA was sequenced using an automated sequencer.

RESULTS

We identified two new variants of the PVRL1 gene at codons 174 and 187 in exon 3. These variants had nucleotide substitutions 520T>A and 560C>A, resulting in S174T and T187N amino acid changes, respectively.

CONCLUSION

Two novel variants of the PVRL 1 gene were identified in nsCL/P patients. These findings suggest that PVRL1 variants make a contribution to nsCL/P in Turkish patients.