A novel locus for X-linked retinitis pigmentosa.
BACKGROUND
Retinitis pigmentosa (RP) is the most prevalent group of inherited retinopathies and demonstrates considerable clinical and genetic heterogeneity, with wide variations in disease severity, progression, and gene involvement. We studied a large family with RP to determine the pattern of inheritance and to identify the disease-causing gene/locus.


METHODS
Ophthalmic examination was performed on 35 family members to identify affected individuals and carriers and to characterise the disease phenotype. Genetic linkage analysis was performed using short tandem repeat (STR) polymorphic markers encompassing the known loci for Xlinked RP (xlRP) including RP2, RP3, RP6, RP23, and RP24. Mutation screening was performed by direct sequencing of PCR-amplified genomic DNA of the RP2 and RPGR genes of the affected individuals.


RESULTS
A highly penetrant, X-linked form of RP was observed in this family. Age of onset was from 5 to 8 years and visual acuity ranged from 20/25 in children to light perception in older adults. Linkage analysis and direct sequencing showed that no known loci/genes were associated with the phenotype in this kindred.


CONCLUSIONS
A novel disease gene locus/loci is responsible for the xlRP phenotype in this family.
Tong
Zongzhong
Z
Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah Health Sciences Center, Salt Lake City, Utah 84132, USA.
Yang
Zhenglin
Z
Meyer
J Jay
JJ
McInnes
Allen W
AW
Xue
Lai
L
Azimi
Asif M
AM
Baird
Jenn
J
Zhao
Yu
Y
Pearson
Erik
E
Wang
Changguan
C
Chen
Yali
Y
Zhang
Kang
K
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D002874:Chromosome Mapping; D004252:DNA Mutational Analysis; D005136:Eye Proteins / Q000235:genetics; D005260:Female; D019204:GTP-Binding Proteins; D040181:Genetic Diseases, X-Linked / Q000235:genetics*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics; D008126:Lod Score; D008297:Male; D008565:Membrane Proteins / Q000235:genetics; D010375:Pedigree; D010641:Phenotype; D012174:Retinitis Pigmentosa / Q000235:genetics*
D005136:Eye Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C072178:RP2 protein, human; C099929:RPGR protein, human; D019204:GTP-Binding Proteins