3. Methods and results
The written informed consent was obtained from the parents and their adult relatives for blood collection and molecular testing. The genomic DNA was extracted from the peripheral blood for defining the carrier status of the involved subjects. Sequence analysis of the entire coding region of the IQCB1/ NPHP5 gene was performed as described previously [22] and showed that the proband and his affected sister werehomozygous carriers for the c.1241-1242delTC in exon 12 of the gene (Fig. 2). We confirmed the mutation in the proband and family members using the same standard sequencing protocol, which utilised the following forward and reverse primers respectively: