Phenotype-phenotype and genotype-phenotype correlations in patients with idiopathic superior oblique muscle palsy.

Idiopathic superior oblique muscle palsy presents, as quantitative phenotypes, vertical deviation and cyclodeviation in eye alignment on clinical testing, and superior oblique muscle hypoplasia on imaging. We determined ARIX and PHOX2B polymorphisms as genotypes, and analyzed phenotype-phenotype and genotype-phenotype correlations in 37 patients with idiopathic superior oblique muscle palsy. Vertical deviations were measured at upright position of the head and head tilt for 30° to either side, and angles of objective excyclodeviations were determined by image analysis on fundus photographs.

Paretic side/normal side ratios of cross-sectional areas of the superior oblique muscle vary largely in idiopathic superior oblique palsy.

Purpose: To search for a new definition of muscle hypoplasia in congenital or idiopathic superior oblique muscle palsy.

Design: Retrospective case-control study.

Methods: Cross-sectional areas of the superior oblique and 4 rectus muscles near the eye globe-optic nerve junction were measured by an image analysis software on magnetic resonance images of 50 patients with congenital or idiopathic superior oblique muscle palsy and 45 patients with other disease conditions serving as a control.

Chromosomes 4q28.3 and 7q31.2 as new susceptibility loci for comitant strabismus.

Purpose: This study was designed to localize chromosomal susceptibility loci for comitant strabismus among Japanese families by genome-wide linkage analyses.

Methods: Fifty-five Japanese families, with at least two members with comitant strabismus (esotropia and/or exotropia), were subject to full ophthalmic examination, careful ocular history, and review of medical records. DNA was obtained and genotyping was performed with PCR amplification of 400 microsatellite markers.

Clinical features, ARIX and PHOX2B nucleotide changes in three families with congenital superior oblique muscle palsy.

We analyzed nucleotide changes in 3 genes, ARIX, PHOX2B, and KIF21A, in 6 patients of 3 families with congenital superior oblique muscle palsy. Three exons of ARIX, 3 exons of PHOX2B, and exons 8, 20, and 21 of KIF21A were amplified by polymerase chain reaction from genomic DNA isolated from the peripheral blood. The DNA fragments were directly sequenced in both directions.