Recent advances in ophthalmic genetics Genetic counseling

Abstract

Some of the recent advances which have influenced our assessment of genetic risk in hereditary disorders of the eye are discussed. The importance of making an exact diagnosis is emphasized, and the concept of genetic heterogeneity is illustrated by three groups of disorders: albinism, retinitis pigmentosa, and the mucopolysaccharidoses. The value of recognizing the heterozygous state in X-linked and in autosomal recessive traits is discussed and the clinical variability of heterozygotes for choroideremia and for X-linked retinitis pigmentosa is described. Two aspects of antenatal diagnosis are considered. The implications of the determination of foetal sex for females heterozygous for X-linked traits is discussed. The current position regarding the detection of biochemical abnormalities in the foetus is stated.