Genetic analysis of adult‐onset cataract in a city‐based ophthalmic hospital

Abstract

Adult‐onset cataract (AOC) is a major ocular health problem and is the number one cause of blindness in the world. It is interesting to note that if the development of cataract is delayed by 10 years, the number of cataract surgeries needed would decrease by 45%. To prevent or delay cataract, the molecular pathological mechanisms underlying the lens change have to be understood, and this requires that the genes involved in such mechanisms should be identified. Hence, in this study we aim to identify AOC families which show a clear mendelian inheritance pattern, as only these families would be ideal for mapping the genes responsible. Over a period of 8 months, from September 1995—April 1996, 17 families with two or more affected members were identified. Segregation analysis showed autosomal dominant inheritance in multiple affected families. We propose to map the genes responsible for cataract in these families by linkage analysis and mutational screening of candidate genes.

The Human W42R γD-Crystallin Mutant Structure Provides a Link between Congenital and Age-related Cataracts*

“…Fractions containing the protein were collected, concentrated, and subjected to gel filtration on a X-ray Data Collection and Processing-X-ray diffraction data were collected up to 1.6 Å on flash-cooled crystals (Ϫ180°C) using a Rigaku FR-E generator with Saturn 944 charge-coupled device detectors at the wavelength corresponding to the copper edge (1.54 Å). Initial indexing of the diffraction patterns indicated that W42R crystallized in the P3 2 21 space group with unit cell dimensions: a ϭ 68.61 Å, b ϭ 68.61 Å, and c ϭ 133.38 Å (␣ ϭ ␤ ϭ 90°and ␥ ϭ 120°). Two molecules are present per asymmetric unit with an estimated solvent content of ϳ44.11% (V m ϭ 2.2 Å 3 /Da) based on the Matthews Probability Calculator (29).…”

“…Cataract, referred to as opacification of all or part of the crystalline lens of the eye (1), can be broadly divided into two classes: early onset (congenital or juvenile) and age-related cataract (2). The congenital cataracts occur at an estimated prevalence of 2.2-2.5 cases per 10,000 live births (3), and ϳ50% of congenital cataracts are inherited (4).…”

“…Human ␥D-crystallin (HGD) 2 is the second most abundant ␥-crystallin of the lens nucleus (8). It is monomeric and contains 173 amino acids.…”

Identification of mutations in HSF4 in dogs of three different breeds with hereditary cataracts

“…In humans cataract is also the most common cause of visual loss 11 . Lens opacities in humans are broadly divided into early onset (congenital and juvenile) and age‐related cataract, with the majority of inherited nonsyndromic cataract showing autosomal dominant inheritance, although X‐linked and autosomal recessive forms are also seen 11,12 .…”

Zebrafish mutants as models for congenital ocular disorders in humans

“…Cataracts can be congenital or age-related and are the leading cause of blindness in humans (Vijaya et al, 1997). Congenital cataracts, while less prevalent than age-related cataracts are thought to be responsible for roughly one-tenth of blindness worldwide (Gilbert et al, 1993).…”