A novel GPR143 duplication mutation in a Chinese family with X-linked congenital nystagmus.
OBJECTIVE
To elucidate the molecular genetic defect of X-linked congenital nystagmus in a Chinese family.


METHODS
Genomic DNA was prepared from peripheral blood. We used allele-sharing analysis to identify the possible locus harboring the disease-causing gene. We screened for mutations in the G protein-coupled receptor 143 gene (GPR143) by direct sequencing of the polymerase chain reaction (PCR)-amplified exons.


RESULTS
In analyzing the candidate gene, GPR143, in the linked region, a 19 base pair (bp) duplication mutation in exon 1 was detected after direct DNA sequence analysis, which cosegregated in all patients of this family and was present in obligate female carriers.


CONCLUSIONS
The identified 19 bp duplication in GPR143 induces a frame-shift and a premature stop codon, resulting in a truncated protein of 105 residues. These results suggest that this novel mutation is associated with the congenital nystagmus observed in this Chinese family and further support that GPR143 mutations are the underlying pathogenesis of the molecular mechanism for congenital nystagmus.
Peng
Yuanyuan
Y
Department of Medical Genetics, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine Peking Union Medical College, Beijing, China.
Meng
Yan
Y
Wang
Zheng
Z
Qin
Mei
M
Li
Xiaoqiao
X
Dian
Yan
Y
Huang
Shangzhi
S
D002681:China; D005136:Eye Proteins / Q000235:genetics*; D005260:Female; D050172:Genes, X-Linked; D040181:Genetic Diseases, X-Linked / Q000235:genetics*; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics*; D009154:Mutation; D020417:Nystagmus, Congenital / Q000235:genetics*; D010375:Pedigree; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA
D005136:Eye Proteins; C095276:GPR143 protein, human; D008562:Membrane Glycoproteins