Fig. 2

Identification of a de novo 73,128 bp deletion at the cone opsin gene cluster a Pedigree of the family with a single affected male (III:2). Reconstructed haplotypes based on microsatellite markers flanking the OPN1LW/MW gene cluster within Xq28 revealed transmission of the X-chromosome from the maternal grandfather (I:1) to the index patient (III:2). b Sanger sequencing traces of the deletion breakpoints observed in the index patient (III:2) and its sequence depicted in red letters in the alignment underneath. Wildtype sequence at the centromeric and the telomeric breakpoint are depicted in black letters at the top and the bottom of the alignment, respectively. The breakpoints define a 73,128 bp deletion (NC_000023.11:g.154,118,184_154,191,311del) including the LCR, the entire OPN1LW gene and the first three exons of the OPN1MW gene. c Segregation analysis demonstrated the de novo occurence of the deletion. A breakpoint PCR amplicon yielded only a product for patient III:2 (“Del”, upper agarose gel panel), whereas a PCR amplicon for exon 3 of OPN1LW and OPN1MW (“Ex3”, lower agarose gel panel) yielded products for the mother (II:1) and the grandfatehr (I:1) but not for the patient (III:2). M1 & M2: DNA size standards; NC: no DNA template negative control; −: empty well. d Schematic representation of the 73,128 bp deletion encompassing the LCR, the entire OPN1LW and 5′ parts of OPN1MW gene in the BCM patient (III:2). Red and green boxes depict individual exons of the OPN1LW and OPN1MW genes, respectively. The localization and composition of Alu elements most likely involved in the mutation event are shown as arrowheads. Physical coordinates refer to Genbank entry NC_000023.11