Autozygosity in a Turkish family with scoliosis, blindness, and arachnodactyly syndrome.

BACKGROUND AND OBJECTIVES

Blindness-scoliosis-arachnodactyly syndrome has been described in a family with parental consanguinity. We present the strategy employed to determine the gene locus responsible for the syndrome.

DESIGN AND SETTING

A retrospective study of blindness-scoliosis-arachnodactyly syndrome patients at the Department of Medical Genetics, Erciyes University, between 2009-2010.

PATIENTS AND METHODS

Whole genome single nucleotide polymorphisms (SNPs) were scanned using a 250K Affymetrix array. We visually evaluated runs of homozygosity shared by two affected brothers that segregated in the entire pedigree with different combinations due to the unclear affected status of some siblings. Two and multiple-point LOD (logarithm [base 10] of odds) score analyses were performed by easyLINKAGEplus v5.08.

RESULTS

Five homozygous blocks over 2 Mb shared by two affected brothers segregated with phenotype in two affected and three unaffected siblings and in the mother whose phenotypes were unequivocal. The longest homozygous block in this analysis was on chromosome 14 between 67817621bp (rs7148416) and 82508151bp (rs17117757). When another sister with positive eye findings was added to the analysis, this region was narrowed to between 67817621bp (rs7148416) and 75657598bp (rs11626830), with a maximum LOD score of 2.3956 by two-point analysis. Three candidate genes were detected in this region.

CONCLUSION

This study contributes to the existing literature on the region 67817621 bp 82508151 bp (rs17117757) on chromosome 14 and the three candidate genes, which could be responsible for the syndrome.