Purpose: To describe 2 sporadic Mexican patients having congenital bilateral, total sclerocornea, aphakia, and microphthalmia associated with novel mutations in the FOXE3 gene.
Methods: Two affected individuals with congenital bilateral, total sclerocornea, aphakia, and microphthalmia underwent detailed examinations including slit-lamp examination, visual acuity, and intraocular pressure measurements. Ocular ultrasonography and ultrasound biomicroscopy were performed. Genomic DNA was isolated from blood leukocytes in each subject, and molecular analysis of the FOXE3 gene was performed. For cosegregation analysis, presumable pathogenic variants were tested by Sanger sequencing in parental DNA.
Results: Molecular screening of FOXE3 was performed in 2 cases with congenital bilateral, total sclerocornea, aphakia, and microphthalmia. In patient 1, genetic analysis demonstrated a novel homozygous c.291C>G (p.Ile97Met) FOXE3 pathogenic variant. In patient 2, compound heterozygosity for the novel c.387C>G (p.Phe129Leu) transversion and for the previously reported c.244A>G (p.Met82Val) transition, was recognized.
Conclusions: The sclerocornea-microphthalmia-aphakia complex is a severe malformative ocular phenotype resulting from mutations in the FOXE3 transcription factor. To date, patients from at least 14 families with this uncommon ocular disorder have been described. The identification of 2 novel pathogenic variants in our patients expands the mutational spectrum in FOXE3-related congenital eye disorders. In addition, we performed a review of the clinical and genotypic characteristics of all published patients carrying biallelic FOXE3 mutations.