Clinical and Genetic Findings in Mexican Patients with Duane Anomaly and Radial Ray Malformations/Okihiro Syndrome.

Background: Okihiro syndrome is an autosomal-dominant condition characterized by radial ray malformations associated with Duane anomaly and other clinical characteristics. SALL4 mutations have been identified in 80-90% of patients with Duane Radial ray defects/Okihiro syndrome. We report the clinical findings and results of SALL4 sequencing from a group of Mexican patients with this disorder. Objective: Clinical description and identification of SALL4 mutations in Mexican subjects with radial defects and Duane anomaly. Materials and methods: Five unrelated index cases were studied. Complete ophthalmologic and general physical examination was performed in all patients. Polymerase chain reaction amplification and automated nucleotide sequencing of coding exons and intron-exon junctions of SALL4 gene were carried out in genomic DNA. Results: A novel heterozygous deletion was identified in one patient. Intragenic heterozygous single nucleotide polymorphisms on SALL4 gene ruled out deletions of some exons in other affected patients in whom non-pathogenic variants were identified by Sanger sequencing. Likewise, multiplex ligation-dependent probe amplification analysis ruled out large deletions in this gene. Conclusion: We observed a low frequency of SALL4 mutations in Mexican patients with clinical criteria of Okihiro syndrome.