Edrees Burhan M, Athar Mohammad, Al-Allaf Faisal A, Taher Mohiuddin M, Khan Wajahatullah, Bouazzaoui Abdellatif, Al-Harbi Naffaa, Safar Ramzia, Al-Edressi Howaida, Alansary Khawala, Anazi Abulkareem, Altayeb Naji, Ahmed Muawia A, Abduljaleel Zainularifeen
Department of Medical Genetics, Faculty of Medicine, Umm Al-Qura University, P.O. Box 715, Makkah 21955, Saudi Arabia; King Fahad Medical City, P.O. Box 59046, Riyadh 11525, Saudi Arabia.
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.
Gene. 2016 Oct 10;591(1):214-226. doi: 10.1016/j.gene.2016.07.021. Epub 2016 Jul 9.
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.
常染色体隐性多囊肾病(ARPKD)是一种罕见的遗传性疾病,其特征为肾脏中形成囊肿。利用Ion torrent PGM下一代测序技术,对与ARPKD表型相关的基因进行了靶向定制测序,以识别候选变异。结果在验证过程中确定了可能致病的疾病变异。在18个样本中的12个样本的PKHD1基因中观察到四个潜在的致病变异,分别为[c.4870C>T, p.(Arg1624Trp)]、[c.5725C>T, p.(Arg1909Trp)]、c.1736C>T, p.(Thr579Met)]和[(c.10628T>G), p.(Leu3543Trp)]。其余患者样本在常染色体显性多囊肾病(ADPKD)致病基因PKD1和PKD2中也显示出少量变异,分别为[c.12433G>A, p.(Val4145Ile)]和[c.1445T>G, p.(Phe482Cys)]。所有致病变异均通过毛细管测序进行了验证,证实了在一名男性先证者的第61外显子中发现的一种新的纯合变异[c.10628T>G, p.(Leu3543Trp)]。基于预测非同义单核苷酸多态性(nsSNPs)对蛋白质功能影响的计算预测,如从耐受中筛选不耐受(SIFT)和多态性表型分析(PolyPhen2),在PKHD1、PKD1和PKD2基因中鉴定出的所有潜在有害变异也具有病理或临床意义。SIFT将我们50%的nsSNPs分类为“有害”,而PolyPhen2将我们45%的nsSNPs鉴定为“可能受损”,两个程序的结果在很大程度上是互补的。综上所述,这些结果表明,NGS策略为在靶向基因序列分析中识别突变提供了一种快速、准确且经济高效的分子诊断工具。