Identification of a novel deletion in the OA1 gene: report of the first Spanish family with X-linked ocular albinism.
BACKGROUND
This study was undertaken to analyse the OA1 gene (GPR143) and its involvement in a Spanish family presenting with nystagmus, a common symptom of X-linked ocular albinism (XLOA).


METHODS
DNA samples from the index case and eight relatives were analysed by multiplex ligation-dependent probe amplification (MLPA). Sequence analysis and restriction assay were used to confirm the results. In addition, an analysis of a STR located in intron 1 of the OA1 gene (OA-CA) was performed.


RESULTS
The father of the proband presented with nystagmus, a feature consistent with XLOA. Mutation screening by multiplex ligation-dependent probe amplification and sequence analysis of the exon 2 of the OA1 gene led to the identification of the novel p.Glu129fsX35 (g.5815delA) mutation in two affected males and four carrier females. Three relatives were found to be non-mutated. The deletion detected resulted in a truncated protein 35 codons downstream and generated a new restriction site for the XcmI endonuclease. Additionally, microsatellite analysis showed co-segregation with the disease in the family.


CONCLUSIONS
A novel deletion in the OA1 gene was identified in a Spanish family with ocular albinism. The mutation detected is likely a loss-of-function alteration. To the best of our knowledge, we describe the first Spanish family known to present with XLOA due to mutations in the OA1 gene.
Martinez-Garcia
Monica
M
Genetics and Genomics Department, Instituto de Investigacion Sanitaria-Fundacion Jimenez Diaz, Madrid, Spain.
Riveiro-Alvarez
Rosa
R
Villaverde-Montero
Cristina
C
Cantalapiedra
Diego
D
Garcia-Sandoval
Blanca
B
Ayuso
Carmen
C
Trujillo-Tiebas
Maria Jose
MJ
D000328:Adult; D016117:Albinism, Ocular / Q000235:genetics*; D000595:Amino Acid Sequence; D041321:Chromosomes, Human, X; D005136:Eye Proteins / Q000235:genetics*; D005192:Family Health; D005260:Female; D017353:Gene Deletion; D006801:Humans; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics*; D008969:Molecular Sequence Data; D010375:Pedigree; D017354:Point Mutation; D013030:Spain
D005136:Eye Proteins; C095276:GPR143 protein, human; D008562:Membrane Glycoproteins