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.