Supplementary Material for: Two Novel <b><i>HOGA1</i></b> Splicing Mutations Identified in a Chinese Patient with Primary Hyperoxaluria Type 3

<b><i>Background:</i></b> Twenty-six <i>HOGA1</i> mutations have been reported in primary hyperoxaluria (PH) type 3 (PH3) patients with c.700 + 5G>T accounting for about 50% of the total alleles. However, PH3 has never been described in Asians. <b><i>Methods:</i></b> A Chinese child with early-onset nephrolithiasis was suspected of having PH. We searched for <i>AGXT</i>, <i>GRHPR</i> and <i>HOGA1</i> gene mutations in this patient and his parents. All coding regions, including intron-exon boundaries, were analyzed using PCR followed by direct sequence analysis. <b><i>Results:</i></b> Two heterozygous mutations not previously described in the literature about <i>HOGA1</i> were identified (compound heterozygous). One mutation was a successive 2 bp substitution at the last nucleotide of exon 6 and at the first nucleotide of intron 6, respectively (c.834_834 + 1GG>TT), while the other one was a guanine to adenine substitution of the last nucleotide of exon 6 (c.834G>A). Direct sequencing analysis failed to find these mutations in 100 unrelated healthy subjects and the functional role on splicing of both variants found in this study was confirmed by a minigene assay based on the pSPL3 exon trapping vector. In addition, we found a SNP in this family (c.715G>A, p.V239I). There were no mutations detected in <i>AGXT</i> and <i>GRHPR</i>. <b><i>Conclusion:</i></b> Two novel <i>HOGA1</i> mutations were identified in association with PH3. This is the first description and investigation on mutant gene analysis of PH3 in an Asian.