Severe autosomal recessive retinitis pigmentosa maps to chromosome 1p13.3-p21.2 between D1S2896 and D1S457 but outside ABCA4.
A severe form of autosomal recessive retinitis pigmentosa (arRP) was identified in a large Pakistani family ascertained in the Punjab province of Pakistan. All affected individuals in the family had night blindness in early childhood, early complete loss of useful vision, and typical RP fundus changes plus macular degeneration. After exclusion of known arRP loci, a genome-wide scan was performed using microsatellite markers at about 10 cM intervals and calculating two-point lod scores. PCR cycle dideoxynucleotide sequencing was used to sequence candidate genes inside the linked region for mutations. RP in this family shows linkage to markers in a 10.5 cM (8.9 Mbp) region of chromosome 1p13.3-p21.2 between D1S2896 and D1S457. D1S485 yields the highest lod score of 6.54 at theta=0. Sequencing the exons and intron-exon boundaries of five candidate genes and six ESTs in this region, OLFM3, GNAI3, LOC126987, FLJ25070, DKFZp586G0123, AV729694, BU662869, BU656110, BU171991, BQ953690, and CA397743, did not identify any causative mutations. This novel locus lies approximately 4.9 cM (7.1 Mbp) from ABCA4, which is excluded from the linked region. Identification and study of this gene may help to elucidate the phenotypic diversity of arRP mapping to this region.
Zhang
Qingjiong
Q
Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Building 10, Room 10B10, 10 center Drive, MSC 1860, Bethesda, MD, 20892-1860, USA.
Zulfiqar
Fareeha
F
Xiao
Xueshan
X
Riazuddin
S Amer
SA
Ayyagari
Radha
R
Sabar
Farooq
F
Caruso
Raphael
R
Sieving
Paul A
PA
Riazuddin
Sheikh
S
Hejtmancik
J Fielding
JF
D000293:Adolescent; D000328:Adult; D002648:Child; D002874:Chromosome Mapping; D002878:Chromosomes, Human, Pair 1; D005091:Exons; D005260:Female; D005838:Genotype; D006801:Humans; D040582:Inheritance Patterns; D007438:Introns; D008297:Male; D018895:Microsatellite Repeats; D010154:Pakistan; D010375:Pedigree; D010641:Phenotype; D012174:Retinitis Pigmentosa / Q000235:genetics* / Q000473:pathology