@article {496, title = {Monoallelic Mutations to DNAJB11 Cause Atypical Autosomal-Dominant Polycystic Kidney Disease.}, journal = {Am J Hum Genet}, volume = {102}, year = {2018}, month = {2018 05 03}, pages = {832-844}, abstract = {

Autosomal-dominant polycystic kidney disease (ADPKD) is characterized by the progressive development of kidney cysts, often resulting in end-stage renal disease (ESRD). This disorder is genetically heterogeneous with \~{}7\% of families genetically unresolved. We performed whole-exome sequencing (WES) in two multiplex ADPKD-like pedigrees, and we analyzed a further 591 genetically unresolved, phenotypically similar families by targeted next-generation sequencing of 65 candidate genes. WES identified a DNAJB11 missense variant (p.Pro54Arg) in two family members presenting with non-enlarged polycystic kidneys and a frameshifting change (c.166_167insTT) in a second family with small renal and liver cysts. DNAJB11 is a co-factor of BiP, a key chaperone in the endoplasmic reticulum controlling folding, trafficking, and degradation of secreted and membrane proteins. Five additional multigenerational families carrying DNAJB11 mutations were identified by the targeted analysis. The clinical phenotype was consistent in the 23 affected members, with non-enlarged cystic kidneys that often evolved to kidney atrophy; 7 subjects reached ESRD from 59 to 89 years. The lack of kidney enlargement, histologically evident interstitial fibrosis in non-cystic parenchyma, and recurring episodes of gout (one family) suggested partial phenotypic overlap with autosomal-dominant tubulointerstitial diseases (ADTKD). Characterization of DNAJB11-null cells and kidney samples from affected individuals revealed a pathogenesis associated with maturation and trafficking defects involving the ADPKD protein, PC1, and ADTKD proteins, such as UMOD. DNAJB11-associated disease is a phenotypic hybrid of ADPKD and ADTKD, characterized by normal-sized cystic kidneys and progressive interstitial fibrosis resulting in late-onset ESRD.

}, keywords = {Adult, Aged, Aged, 80 and over, Alleles, Amino Acid Sequence, Base Sequence, Epithelial Cells, Family, Female, HSP40 Heat-Shock Proteins, Humans, Loop of Henle, Male, Middle Aged, Mutation, Pedigree, Polycystic Kidney, Autosomal Dominant, TRPP Cation Channels, Uromodulin, Whole Exome Sequencing, Young Adult}, issn = {1537-6605}, doi = {10.1016/j.ajhg.2018.03.013}, author = {Cornec-Le Gall, Emilie and Olson, Rory J and Besse, Whitney and Heyer, Christina M and Gainullin, Vladimir G and Smith, Jessica M and Audr{\'e}zet, Marie-Pierre and Hopp, Katharina and Porath, Binu and Shi, Beili and Baheti, Saurabh and Senum, Sarah R and Arroyo, Jennifer and Madsen, Charles D and F{\'e}rec, Claude and Joly, Dominique and Jouret, Fran{\c c}ois and Fikri-Benbrahim, Oussamah and Charasse, Christophe and Coulibaly, Jean-Marie and Yu, Alan S and Khalili, Korosh and Pei, York and Somlo, Stefan and Le Meur, Yannick and Torres, Vicente E and Harris, Peter C} } @article {447, title = {A noncoding variant in GANAB explains isolated polycystic liver disease (PCLD) in a large family.}, journal = {Hum Mutat}, volume = {39}, year = {2018}, month = {2018 03}, pages = {378-382}, abstract = {

Expanded mutation detection and novel gene discovery for isolated polycystic liver disease (PCLD) are necessary as 50\% of cases do not have identified mutations in the seven published disease genes. We investigated a family with five affected siblings for which no loss-of-function variants were identified by whole exome sequencing analysis. SNP genotyping and linkage analysis narrowed the candidate regions to \~{}8\% of the genome, which included two published PCLD genes in close proximity to each other, GANAB and LRP5. Based on these findings, we re-evaluated the exome sequencing data and identified a novel intronic nine base pair deletion in the vicinity of the GANAB exon 24 splice donor that had initially been discarded by the sequence analysis pipelines. We used a minigene assay to show that this deletion leads to skipping of exon 24 in cell lines and primary human cholangiocytes. These findings prompt genomic evaluation beyond the coding region to enhance mutation detection in PCLD and to avoid premature implication of other genes in linkage disequilibrium.

}, keywords = {Base Sequence, Cysts, DNA, Intergenic, Evolution, Molecular, Exons, Glucosidases, Humans, Liver Diseases, Low Density Lipoprotein Receptor-Related Protein-5, Mutation}, issn = {1098-1004}, doi = {10.1002/humu.23383}, author = {Besse, Whitney and Choi, Jungmin and Ahram, Dina and Mane, Shrikant and Sanna-Cherchi, Simone and Torres, Vicente and Somlo, Stefan} } @article {402, title = {Isolated polycystic liver disease genes define effectors of polycystin-1 function.}, journal = {J Clin Invest}, volume = {127}, year = {2017}, month = {2017 May 01}, pages = {1772-1785}, abstract = {

Dominantly inherited isolated polycystic liver disease (PCLD) consists of liver cysts that are radiologically and pathologically identical to those seen in autosomal dominant polycystic kidney disease, but without clinically relevant kidney cysts. The causative genes are known for fewer than 40\% of PCLD index cases. Here, we have used whole exome sequencing in a discovery cohort of 102 unrelated patients who were excluded for mutations in the 2 most common PCLD genes, PRKCSH and SEC63, to identify heterozygous loss-of-function mutations in 3 additional genes, ALG8, GANAB, and SEC61B. Similarly to PRKCSH and SEC63, these genes encode proteins that are integral to the protein biogenesis pathway in the endoplasmic reticulum. We inactivated these candidate genes in cell line models to show that loss of function of each results in defective maturation and trafficking of polycystin-1, the central determinant of cyst pathogenesis. Despite acting in a common pathway, each PCLD gene product demonstrated distinct effects on polycystin-1 biogenesis. We also found enrichment on a genome-wide basis of heterozygous mutations in the autosomal recessive polycystic kidney disease gene PKHD1, indicating that adult PKHD1 carriers can present with clinical PCLD. These findings define genetic and biochemical modulators of polycystin-1 function and provide a more complete definition of the spectrum of dominant human polycystic diseases.

}, keywords = {Adult, Animals, Cell Line, Transformed, Cysts, Endoplasmic Reticulum, Female, Genome-Wide Association Study, Glucosidases, Glucosyltransferases, Heterozygote, Humans, Intracellular Signaling Peptides and Proteins, Liver Diseases, Male, Membrane Proteins, Mice, Mutation, SEC Translocation Channels, TRPP Cation Channels}, issn = {1558-8238}, doi = {10.1172/JCI90129}, author = {Besse, Whitney and Dong, Ke and Choi, Jungmin and Punia, Sohan and Fedeles, Sorin V and Choi, Murim and Gallagher, Anna-Rachel and Huang, Emily B and Gulati, Ashima and Knight, James and Mane, Shrikant and Tahvanainen, Esa and Tahvanainen, Pia and Sanna-Cherchi, Simone and Lifton, Richard P and Watnick, Terry and Pei, York P and Torres, Vicente E and Somlo, Stefan} } @article {26, title = {Collapsing glomerulopathy in a young woman with APOL1 risk alleles following acute parvovirus B19 infection: a case report investigation.}, journal = {BMC Nephrol}, volume = {17}, year = {2016}, month = {2016 Sep 06}, pages = {125}, abstract = {

BACKGROUND: Collapsing Glomerulopathy (CG), also known as the collapsing variant of Focal Segmental Glomerulosclerosis (FSGS), is distinct in both its clinical severity and its pathophysiologic characteristics from other forms of FSGS. This lesion occurs disproportionally in patients carrying two APOL1 risk alleles, and is the classic histologic lesion resulting from Human Immunodeficiency Virus (HIV) infection of podocytes. Other viral infections, including parvovirus B19, and drugs such as interferon that perturb the immune system, have also been associated with CG. Despite significant advances, explaining such genetic and immune/infectious associations with causative mechanisms and supporting evidence has proven challenging.

CASE PRESENTATION: We report the case of a healthy (HIV-negative) pregnant 36~year-old Caribbean-American woman who presented with nephrotic syndrome and fetal demise in the setting of acute parvovirus B19 infection. A series of three renal biopsies and rapid clinical course showed progression from significant podocyte injury with mild light microscopy findings to classic viral-associated CG to ESRD in less than 3~months. Genetic analysis revealed two APOL1 G1 risk alleles.

CONCLUSIONS: This is the first published case report of CG in the setting of acute parvovirus infection in a patient with two APOL1 risk allelles, and parvoviral proteins identified in renal epithelium on kidney biopsy. These findings support the causative role of parvovirus B19 infection in the development of CG on the background of APOL1 genetic risk.

}, keywords = {Acute Disease, Adult, Alleles, Apolipoprotein L1, Female, Glomerulosclerosis, Focal Segmental, Humans, Kidney Failure, Chronic, Parvoviridae Infections, Parvovirus B19, Human, Pregnancy, Pregnancy Complications, Infectious}, issn = {1471-2369}, doi = {10.1186/s12882-016-0330-7}, author = {Besse, Whitney and Mansour, Sherry and Jatwani, Karan and Nast, Cynthia C and Brewster, Ursula C} }