Lack of mutations in the PVRL3 gene in North American caucasians with non-syndromic cleft lip/palate

Abstract

Cleft lip with or without cleft palate (CLP) is one of the most common birth defects. In about 70% of cases, CLP occurs as an isolated anomaly, denoted non-syndromic CLP (nsCLP). Genetic linkage and association studies have implicated many loci in susceptibility to nsCLP, including some members of the nectin gene family. We performed mutation screening of the PVRL3 gene that encodes nectin-3 in 73 unrelated Caucasian nsCLP patients and 105 unrelated controls from North America. We detected no sequence variants in the PVRL3 gene in either the nsCLP patients or the controls. These data suggest that PVRL3 is not an important susceptibility gene for nsCLP in the North American Caucasian population.Key words: orofacial clefts, nectins, PVRL3, mutation analysis. Cleft lip with or without cleft palate (CLP; MIM 119530) is among the most common birth defects, occurring in most populations in about 0.2 to 3 per 1000 liveborn infants (Schutte and Murray, 1999;Spritz, 2001;Cobourne, 2004). In about 30% of cases, CLP occurs as part of heritable Mendelian syndromes, but in the majority of cases it occurs as an isolated, complex trait, denoted non-syndromic CLP (nsCLP). Genetic linkage and association studies have implicated many loci in the pathogenesis of nsCLP, including PVRL1, which encodes nectin-1, a cell adhesion molecule (Reymond et al., 2000;Satoh-Horikawa et al., 2000). Homozygous loss-of-function mutations in PVRL1 result in a rare recessive CLP syndrome, CLPED1 (Suzuki et al., 2000), and heterozygous PRVL1 variants have been associated with nsCLP (Sozen et al., 2001;Turhani et al., 2005;Avila et al., 2006;Neiswanger et al., 2006;Scapoli et al., 2006;Tseng et al., 2006).Two other nectin-family paralogues, PVR and PVRL2, were recently evaluated as candidate genes for nsCLP and found to show evidence of genetic association (Warrington et al., 2006). Here, we describe the analysis of another member of the nectin gene family, PVRL3, which encodes nectin-3, as a candidate gene for nsCLP. PVRL3 is expressed mainly in testis and placenta, and at a lower level in heart, brain, lung, liver, and kidney (Reymond et al., 2000;Satoh-Horikawa et al., 2000). It is located on chromosome 3q13.13, which has not been implicated in the pathogenesis of nsCL/P so far.We screened for variants in the six coding exons of the PVRL3 gene and adjacent intron and non-coding sequences in 73 unrelated North American Caucasian patients with nsCLP (33 from Texas, 20 from Maryland, 20 from Ohio) and 100 unrelated Caucasian unaffected controls, using the single-stranded conformation polymorphism (SSCP)/heterduplex technique (Lee et al., 1995). Exon 6 was divided into two overlapping amplicons, 6A and 6B. PCR and sequencing primers were:Exon 1, 5'-AGCGTTCGGCCAAGTGTCAG-3' / 5'-TCCAGAGAACGGCTGGCAGA-3'; Exon 2, 5'-GAAG GGAGGAGAGTGTTGAC-3' / 5'-CTTCACCACTATC ACCAAAATAC-3'; Exon 3, 5'-GCAGTTGTCCTTAAG CTTGTG-3'/5'-AGTTTGATAAACATGCTGAC-3'; Exon 4, 5'-GTAATCTGTCCTGTCATGC-3' / 5'-CTGCTCC ACACAGATTTGA-3'; Exon 5, 5'-CAGTGAATTTTGT CTGAGATGC-3' / 5'-CTCA...

Two novel genes TOX3 and COL21A1 in large extended Malay families with nonsyndromic cleft lip and/or palate

“…Early assumption that the selected NSCLP family had a lower copy number of PVRL3 compared to the normal individuals was not significantly proven. A normal detection of PVRL3 copy number in the NSCLP family reflected the finding by Sözen, Hecht, and Spritz (2008) that found no evidence of sequence variations in exons, intron, and noncoding sequences of PVRL3 among North American Caucasian population (Sözen et al, 2008). On contrary, other nectin-family paralogues, PVR, PVRL1, and PVRL2, have been identified as candidate genes and play a role in etiology of NSCLP via genome-wide linkage and association studies (Sözen et al, 2008;Warrington et al, 2006).…”

Discovery of candidate genes for nonsyndromic cleft lip palate through genome-wide linkage analysis of large extended families in the Malay population

“…Suggestive linkage of LOD score in family 99 and HLOD ≥1 in total family for 3q13.3-13.33 chromosomal region brought to the interest of this study, with the findings of Poliovirus Receptor-Related 3 ( PVRL3 ) gene related to orofacial cleft. Sözen et al, [ 32 ] has screened several regions of coding exons, adjacent introns and noncoding sequences of PVRL3 and concluded that no variant mutations found in the selected regions in Caucasian polpulations. However, there is possibility that the variants were not detected by the SSCP/heteroduplex screening method used [ 32 ].…”

“…Sözen et al, [ 32 ] has screened several regions of coding exons, adjacent introns and noncoding sequences of PVRL3 and concluded that no variant mutations found in the selected regions in Caucasian polpulations. However, there is possibility that the variants were not detected by the SSCP/heteroduplex screening method used [ 32 ]. Suggestive linkage at chromosomal locus 6p12.2 from family 58 harbor COL21A1 (alpha chain of type XX1 collagen) that have never reported associated with craniofacial development.…”