Kohl Stefan, Hwang Daw-Yang, Dworschak Gabriel C, Hilger Alina C, Saisawat Pawaree, Vivante Asaf, Stajic Natasa, Bogdanovic Radovan, Reutter Heiko M, Kehinde Elijah O, Tasic Velibor, Hildebrandt Friedhelm
Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts;
Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts; Division of Nephrology, Department of Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan;
J Am Soc Nephrol. 2014 Sep;25(9):1917-22. doi: 10.1681/ASN.2013101103. Epub 2014 Apr 3.
Congenital anomalies of the kidney and urinary tract (CAKUT) account for approximately 40% of children with ESRD in the United States. Hitherto, mutations in 23 genes have been described as causing autosomal dominant isolated CAKUT in humans. However, >90% of cases of isolated CAKUT still remain without a molecular diagnosis. Here, we hypothesized that genes mutated in recessive mouse models with the specific CAKUT phenotype of unilateral renal agenesis may also be mutated in humans with isolated CAKUT. We applied next-generation sequencing technology for targeted exon sequencing of 12 recessive murine candidate genes in 574 individuals with isolated CAKUT from 590 families. In 15 of 590 families, we identified recessive mutations in the genes FRAS1, FREM2, GRIP1, FREM1, ITGA8, and GREM1, all of which function in the interaction of the ureteric bud and the metanephric mesenchyme. We show that isolated CAKUT may be caused partially by mutations in recessive genes. Our results also indicate that biallelic missense mutations in the Fraser/MOTA/BNAR spectrum genes cause isolated CAKUT, whereas truncating mutations are found in the multiorgan form of Fraser syndrome. The newly identified recessive biallelic mutations in these six genes represent the molecular cause of isolated CAKUT in 2.5% of the 590 affected families in this study.
先天性肾脏和尿路畸形(CAKUT)在美国约占终末期肾病儿童的40%。迄今为止,已有23个基因的突变被描述为可导致人类常染色体显性遗传的孤立性CAKUT。然而,超过90%的孤立性CAKUT病例仍未得到分子诊断。在此,我们推测,在具有单侧肾发育不全这一特定CAKUT表型的隐性小鼠模型中发生突变的基因,在患有孤立性CAKUT的人类中也可能发生突变。我们应用新一代测序技术,对来自590个家庭的574例患有孤立性CAKUT的个体的12个隐性小鼠候选基因进行靶向外显子测序。在590个家庭中的15个家庭里,我们在FRAS1、FREM2、GRIP1、FREM1、ITGA8和GREM1基因中鉴定出隐性突变,所有这些基因在输尿管芽和后肾间充质的相互作用中发挥作用。我们表明,孤立性CAKUT可能部分由隐性基因的突变引起。我们的结果还表明,Fraser/MOTA/BNAR谱系基因中的双等位基因错义突变会导致孤立性CAKUT,而截短突变则见于Fraser综合征的多器官形式。在这六个基因中新鉴定出的隐性双等位基因突变代表了本研究中590个受影响家庭中2.5%的孤立性CAKUT的分子病因。