TY - JOUR
T1 - Biochemical defects in ABCR protein variants associated with human retinopathies
AU - Sun, Hui
AU - Smallwood, Philip M.
AU - Nathans, Jeremy
N1 - Funding Information:
We thank C. Riley, C. Davenport, M. Kazienko and J. Ptak for DNA synthesis and sequencing; R. Molday for the gift of cells producing Rim3F4; R. Allikmets, J. Lupski and E. Stone for sharing their data on ABCR variants and for helpful discussions; S. Almashanu for advice; and A. Rattner and P. Tong for helpful comments on the manuscript. This work was supported by the Howard Hughes Medical Institute and the National Eye Institute (NIH).
PY - 2000/10
Y1 - 2000/10
N2 - Mutations in the gene encoding ABCR (ABCA4), a photoreceptor-specific ATP-binding cassette (ABC) transporter, are responsible for autosomal recessive Stargardt disease (STGD), an early onset macular degeneration, and some forms of autosomal recessive cone-rod dystrophy and autosomal recessive retinitis pigmentosa. Heterozygosity for ABCA4 mutations may also represent a risk factor for age-related macular degeneration (AMD), although this idea is controversial. An ongoing challenge in the analysis of ABCA4-based retinopathies arises from the observation that most of the ABCA4 sequence variants identified so far are missense mutations that are rare in both patient and control populations. With the current sample size of most sequence variants, one cannot determine statistically whether a particular sequence variant is pathogenic or neutral. A related challenge is to determine the degree to which each pathogenic variant impairs ABCR function, as genotype-phenotype analyses indicate that age of onset and disease severity correlate with different ABCA4 alleles. To address these questions, we performed a functional analysis of human ABCR and its variants. These experiments reveal a wide spectrum of biochemical defects in these variants and provide insight into the transport mechanism of ABCR.
AB - Mutations in the gene encoding ABCR (ABCA4), a photoreceptor-specific ATP-binding cassette (ABC) transporter, are responsible for autosomal recessive Stargardt disease (STGD), an early onset macular degeneration, and some forms of autosomal recessive cone-rod dystrophy and autosomal recessive retinitis pigmentosa. Heterozygosity for ABCA4 mutations may also represent a risk factor for age-related macular degeneration (AMD), although this idea is controversial. An ongoing challenge in the analysis of ABCA4-based retinopathies arises from the observation that most of the ABCA4 sequence variants identified so far are missense mutations that are rare in both patient and control populations. With the current sample size of most sequence variants, one cannot determine statistically whether a particular sequence variant is pathogenic or neutral. A related challenge is to determine the degree to which each pathogenic variant impairs ABCR function, as genotype-phenotype analyses indicate that age of onset and disease severity correlate with different ABCA4 alleles. To address these questions, we performed a functional analysis of human ABCR and its variants. These experiments reveal a wide spectrum of biochemical defects in these variants and provide insight into the transport mechanism of ABCR.
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U2 - 10.1038/79994
DO - 10.1038/79994
M3 - Article
C2 - 11017087
AN - SCOPUS:0033775698
SN - 1061-4036
VL - 26
SP - 242
EP - 246
JO - Nature Genetics
JF - Nature Genetics
IS - 2
ER -