Identification of a novel GPR143 deletion in a Chinese family with X-linked congenital nystagmus.
OBJECTIVE
To map and identify the genetic mutation underlying X-linked congenital nystagmus in a Chinese family.


METHODS
Genomic DNA was prepared from peripheral blood, and linkage analysis was performed using short tandem repeat (STR) polymorphism markers. We used Cyrillic software to manage pedigree and haplotype data and used MLINK to calculate LOD scores. Dye-terminator cycle-sequencing was used to detect the sequence variation of polymerase chain reaction (PCR)-amplified exons.


RESULTS
Linkage analysis mapped the disease-causing gene to Xp22.3 with a significant two-point LOD score (Z) at marker DXS7103 (Z=3.16, recombination fraction [theta]=0). Haplotype analysis in this region supported the result. In analyzing the candidate gene in the linked region, we found a 37-bp deletion in exon 1 of GPR143 in all male patients.


CONCLUSIONS
The revealed 37-bp deletion in GPR143 is frameshift and is predicted to result in a truncated protein of 93 residues. These results indicate that this novel GPR143 mutation is associated with the congenital nystagmus observed in this Chinese family.
Zhou
Pingtong
P
Institute of Health Sciences, Shanghai Institutes for Biological Sciences (SIBS), Chinese Academy of Sciences (CAS) & Shanghai Jiao Tong University School of Medicine (SJTUSM), Shanghai, China.
Wang
Zhiqiang
Z
Zhang
Jing
J
Hu
Landian
L
Kong
Xiangyin
X
D044466:Asian People / Q000235:genetics*; D001483:Base Sequence; D002681:China; D041321:Chromosomes, Human, X / Q000235:genetics; D004252:DNA Mutational Analysis; D005136:Eye Proteins / Q000235:genetics*; D005260:Female; D040181:Genetic Diseases, X-Linked / Q000235:genetics*; D006239:Haplotypes; D006801:Humans; D008126:Lod Score; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics*; D008969:Molecular Sequence Data; D020417:Nystagmus, Congenital / Q000235:genetics*; D010375:Pedigree; D017384:Sequence Deletion
D005136:Eye Proteins; C095276:GPR143 protein, human; D008562:Membrane Glycoproteins