Molecular Analysis of Microphthalmia/Anophthalmia

Overview

This study will try to learn more about the genetic cause and symptoms of microphthalmia (small eyes) or anophthalmia (absence of one or both eyes). Patients with microphthalmia or anophthalmia with mental retardation may be eligible for this study. Patients' parents and siblings will also be included for genetic studies. Patients may participate in both the clinical and laboratory parts of the study or just the laboratory part, as described below: Laboratory The laboratory study consists of DNA analysis to determine the genetic cause of microphthalmia/anophthalmia. The DNA sample is obtained using one of the following methods: * Blood draw - for young children, a numbing cream is applied to the skin before the needlestick to decrease the pain * Skin biopsy - a small piece of skin (about 1/8-inch in diameter) is removed surgically after the area has been numbed with an anesthetic * Cotton swab - a specimen is collected from inside the cheek using a cotton swab. This is done only for patients who cannot provide a blood or skin sample. * Prenatal sample - If, in the case of newborns, specimens are left from prenatal testing, these can be used instead of a blood sample. Some patients may have a permanent cell line grown from the blood or skin sample for use in future research tests. Clinical For the clinical study, participants undergo some or all of the following procedures at the NIH Clinical Center: * Physical examination * Clinical photographs, X-rays, blood tests * Magnetic resonance imaging (MRI) scan of the brain - a diagnostic procedure that uses a magnetic field and radio waves instead of X-rays to produce images of the brain

We propose to identify and analyze the underlying mechanistic pathway of X-linked microphthalmia/anophthalmia. This is a heterogeneous group that includes syndromic microphthalmia 1 (MCOPS1) OMIM #309800, and syndromic microphthalmia 2 (MCOPS2) OMIM #300166 and other, as yet to be defined, malformations of the globe. We have identified a causative gene for MCOPS1 (Ng, et al 2004). To further delineate these conditions, we will study families with these features through a combined clinical and molecular approach. Specimens will be collected and evaluated in the laboratory by linkage analysis, physical mapping, candidate gene characterization, mutation screening, genotype-phenotype correlation, and cell biologic studies of normal and mutant proteins.