Whole genome genotyping mapped regions on chromosome 2 and 18 in a family segregating Waardenburg syndrome type II.

OBJECTIVES: Waardenburg syndrome is a rare genetic disorder. It is characterized by sensorineural hearing impairment and pigment defects of the skin, hair and iris. In some cases abnormalities in the tissues derived from neural crest have also been reported. Mutations in several genes have been reported as an underlying cause of Waardenburg syndrome. Objective of this study is to identify the chromosomal region(s) associated with Waardenburg syndrome in an extended Saudi family.

METHODS: Genomic DNA was extracted from fifteen individuals of a Saudi family segregating Waardenburg syndrome. Whole genome SNP genotyping was performed to identify common identity by descent chromosomal region(s) shared by affected individuals.

RESULTS: Pedigree analysis confirm autosomal dominant inheritance of Waardenburg syndrome type II in a family. Whole genome SNP genotypes were analyzed using AutoSNPa and DominantMapper tools. Shared identity by descent chromosomal regions were identified on chromosome 2 and chromosome 18. Regions were checked for known Waardenburg syndrome genes. No known gene is present in both regions.

CONCLUSIONS: In summary, we identified novel chromosomal regions associated with Waardenburg syndrome type II in a Saudi family. Deep sequencing of a complete candidate regions are required to identify the gene underlying Waardenburg syndrome in this family.