ABSTRACT
AIM AND METHOD: We analysed DNA samples isolated from individuals born with cleft lip and cleft palate to identify deletions and duplications of candidate gene loci using array comparative genomic hybridisation (array-CGH). RESULTS: Of 83 syndromic cases analysed we identified one subject with a previously unknown 2.7 Mb deletion at 22q11.21 coinciding with the DiGeorge syndrome region. Eighteen of the syndromic cases had clinical features of Van der Woude syndrome and deletions were identified in five of these, all of which encompassed the interferon regulatory factor 6 (IRF6) gene. In a series of 104 non-syndromic cases we found one subject with a 3.2 Mb deletion at chromosome 6q25.1-25.2 and another with a 2.2 Mb deletion at 10q26.11-26.13. Analyses of parental DNA demonstrated that the two deletion cases at 22q11.21 and 6q25.1-25.2 were de novo, while the deletion of 10q26.11-26.13 was inherited from the mother, who also has a cleft lip. These deletions appear likely to be causally associated with the phenotypes of the subjects. Estrogen receptor 1 (ESR1) and fibroblast growth factor receptor 2 (FGFR2) genes from the 6q25.1-25.2 and 10q26.11-26.13, respectively, were identified as likely causative genes using a gene prioritization software. CONCLUSION: We have shown that array-CGH analysis of DNA samples derived from cleft lip and palate subjects is an efficient and productive method for identifying candidate chromosomal loci and genes, complementing traditional genetic mapping strategies.
Subject(s)
Cleft Lip/genetics , Cleft Palate/genetics , Base Sequence , Child , Chromosome Deletion , Chromosome Mapping , Chromosomes, Artificial, Bacterial/genetics , Chromosomes, Human, Pair 10/genetics , Chromosomes, Human, Pair 22/genetics , Chromosomes, Human, Pair 6/genetics , DNA/genetics , Female , Gene Dosage , Genetic Variation , Humans , Male , Nucleic Acid Hybridization , Phenotype , SyndromeABSTRACT
Isolated or nonsyndromic cleft lip and palate (NS CLP) is a complex disorder resulting from multiple genetic and environmental factors. NS CLP has a birth prevalence of 1 per 500 in the Philippines where large families provide an opportunity for gene localization. Genotyping of 392 microsatellite repeat markers at 10 cM intervals over the genome was performed by the Center for Inherited Disease Research (CIDR) on 220 Filipino families with 567 affected and 1,109 unaffected family members genotyped. Among the most statistically significant results from analysis of the genome-wide scan data was a 20 cM region at 8p11-23 in which markers had LODs > or =1.0. This region on 8p11-23 has not been found in any previous genome wide scan nor does it contain any of the candidate genes widely studied in CLP. Fine mapping in 8p11-23 was done in the 220 families plus an additional 51 families, using SNP markers from 10 known genes (FGFR1, NRG1, FZD3, SLC8A1, PPP3CC, EPHX2, BNIP3L, EGR3, PPP2R2A, and NAT1) within the 20 cM region of 8p11-23. Linkage and association analyses of these SNPs yield suggestive results for markers in FGFR1 (recessive multipoint HLOD 1.07) and BAG4 (recessive multipoint HLOD 1.31).
