This family consists of several eukaryotic cleft lip and palate transmembrane protein 1 sequences. Cleft lip with or without cleft palate is a common birth defect that is genetically complex. The nonsyndromic forms have been studied genetically using linkage and candidate-gene association studies with only partial success in defining the loci responsible for orofacial clefting. CLPTM1 encodes a transmembrane protein and has strong homology to two Caenorhabditis elegans genes, suggesting that CLPTM1 may belong to a new gene family [1]. This family also contains the human cisplatin resistance related protein CRR9p which is associated with CDDP-induced apoptosis [2].

1: Characterization of a novel gene disrupted by a balanced chromosomal translocation t(2;19)(q11.2;q13.3) in a family with cleft lip and palate. Yoshiura K, Machida J, Daack-Hirsch S, Patil SR, Ashworth LK, Hecht JT, Murray JC; Genomics 1998;54:231-240. PMID:9828125

2: A novel gene, CRR9, which was up-regulated in CDDP-resistant ovarian tumor cell line, was associated with apoptosis. Yamamoto K, Okamoto A, Isonishi S, Ochiai K, Ohtake Y; Biochem Biophys Res Commun 2001;280:1148-1154. PMID:11162647