Gene 2016 Oct 9;591(1):214-226. Epub 2016 Jul 9.
Department of Medical Genetics, Faculty of Medicine, Umm Al-Qura University, P.O. Box 715, Makkah 21955, Saudi Arabia; Science and Technology Unit, Umm Al -Qura University, P.O. Box 715, Makkah 21955, Saudi Arabia. Electronic address:
Autosomal recessive polycystic kidney disease (ARPKD) a rare genetic disorder, described by formation of cysts in the kidney. A targeted customized sequencing of genes implicated in ARPKD phenotype was performed to identify candidate variants using the Ion torrent PGM next-generation sequencing. The results identified likely pathogenic disease causing variants during the validation process. Four potential pathogenic variants [c.4870C>T, p.(Arg1624Trp)], [c.5725C>T, p.(Arg1909Trp)], c.1736C>T, p.(Thr579Met)] and [(c.10628T>G), p.(Leu3543Trp)] were observed in PKHD1 gene among 12 out of 18 samples. The rest of the patient samples also showed few variants in ADPKD (Autosomal Dominant Polycystic Kidney Disease) disease causing genes PKD1 and PKD2 i.e. [c.12433G>A, p.(Val4145Ile)] and [c.1445T>G, p.(Phe482Cys)], respectively. All causative variants were validated by capillary sequencing, confirming the presence of a novel homozygous variants [c.10628T>G, p.(Leu3543Trp)] found in exon 61 of a male proband. All potentially deleterious variants identified in PKHD1, PKD1, and PKD2 gene, also exhibited pathologically or clinically significance based on the computational predictions involved in predicting the impact of non-synonymous SNPs (nsSNPs) on protein function such as Sorting Intolerant From Tolerant (SIFT) and Polymorphism Phenotyping (PolyPhen2). SIFT classified 50% of our nsSNPs as "deleterious", while PolyPhen2 identified 45% of our nsSNPs as "Probably damaged" and the results from both programs were largely complementary. Taken together, these results suggest that the NGS strategies provide a fast, accurate and cost-effective molecular diagnostic tool for identifying mutations in targeted genes sequence analysis.