Clinical course and outcome after kidney transplantation in patients with C3 glomerulonephritis due to CFHR5 nephropathy.

Background: Complement factor H-related protein 5 (CFHR5) nephropathy is an inherited renal disease characterized by microscopic and synpharyngitic macroscopic haematuria, C3 glomerulonephritis and renal failure. It is caused by an internal duplication of exons 2-3 within the CFHR5 gene resulting in dysregulation of the alternative complement pathway. The clinical characteristics and outcomes of transplanted patients with this rare familial nephropathy remain unknown.

COL4A5 and LAMA5 variants co-inherited in familial hematuria: digenic inheritance or genetic modifier effect?

Background: About 40-50% of patients with familial microscopic hematuria (FMH) caused by thin basement membrane nephropathy (TBMN) inherit heterozygous mutations in collagen IV genes (COL4A3, COL4A4). On long follow-up, the full phenotypic spectrum of these patients varies a lot, ranging from isolated MH or MH plus low-grade proteinuria to chronic renal failure of variable degree, including end-stage renal disease (ESRD).

Methods: Here, we performed Whole Exome Sequencing (WES) in patients of six families, presenting with autosomal dominant FMH, with or without progression to proteinuria and loss of renal function, all previously found negative for severe collagen IV mutations.

A functional variant in NEPH3 gene confers high risk of renal failure in primary hematuric glomerulopathies. Evidence for predisposition to microalbuminuria in the general population.

Background: Recent data emphasize that thin basement membrane nephropathy (TBMN) should not be viewed as a form of benign familial hematuria since chronic renal failure (CRF) and even end-stage renal disease (ESRD), is a possible development for a subset of patients on long-term follow-up, through the onset of focal and segmental glomerulosclerosis (FSGS). We hypothesize that genetic modifiers may explain this variability of symptoms.

Methods: We looked in silico for potentially deleterious functional SNPs, using very strict criteria, in all the genes significantly expressed in the slit diaphragm (SD).

Molecular and Clinical Investigation of Cystinuria in the Greek-Cypriot Population.

Background And Aims: Cystinuria represents 3% of nephrolithiasis in humans. Two genes have been identified as the main genetic causes of cystinuria, SLC3A1 and SLC7A9, with an autosomal recessive mode of inheritance. In the present study, we studied for the first time, genetically and clinically, all the cystinuric families identified so far in the Greek-Cypriot population.

Frequency of COL4A3/COL4A4 mutations amongst families segregating glomerular microscopic hematuria and evidence for activation of the unfolded protein response. Focal and segmental glomerulosclerosis is a frequent development during ageing.

Familial glomerular hematuria(s) comprise a genetically heterogeneous group of conditions which include Alport Syndrome (AS) and thin basement membrane nephropathy (TBMN). Here we investigated 57 Greek-Cypriot families presenting glomerular microscopic hematuria (GMH), with or without proteinuria or chronic kidney function decline, but excluded classical AS. We specifically searched the COL4A3/A4 genes and identified 8 heterozygous mutations in 16 families (28,1%).

Epistatic role of the MYH9/APOL1 region on familial hematuria genes.

Familial hematuria (FH) is explained by at least four different genes (see below). About 50% of patients develop late proteinuria and chronic kidney disease (CKD). We hypothesized that MYH9/APOL1, two closely linked genes associated with CKD, may be associated with adverse progression in FH.

C3 glomerulonephritis/CFHR5 nephropathy is an endemic disease in Cyprus: clinical and molecular findings in 21 families.

Microscopic haematuria is the presenting symptom of several conditions, either heritable or acquired. A well-recognized familial condition is Alport syndrome, either of X-linked or autosomal recessive inheritance, as well as thin basement membrane nephropathy (TBMN) because of heterozygous collagen IV mutations. Even though microscopic haematuria of TBMN was long considered as a benign disease with excellent prognosis, more recent data suggest that development of chronic kidney disease (CKD) and even end-stage kidney disease (ESKD) is not a rare finding, perhaps owing to the cofounding role of modifier genes and other factors.

A miR-1207-5p binding site polymorphism abolishes regulation of HBEGF and is associated with disease severity in CFHR5 nephropathy.

Heparin binding epidermal growth factor (HBEGF) is expressed in podocytes and was shown to play a role in glomerular physiology. MicroRNA binding sites on the 3'UTR of HBEGF were predicted using miRWalk algorithm and followed by DNA sequencing in 103 patients diagnosed with mild or severe glomerulopathy. A single nucleotide polymorphism, miRSNP C1936T (rs13385), was identified at the 3'UTR of HBEGF that corresponds to the second base of the hsa-miR-1207-5p seed region.

Evidence that NPHS2-R229Q predisposes to proteinuria and renal failure in familial hematuria.

Background: Familial hematuria (FH) is associated with at least two pathological entities: thin basement membrane nephropathy (TBMN), caused by heterozygous COL4A3/COL4A4 mutations, and C3 nephropathy caused by CFHR5 mutations. It is now known that TBMN patients develop proteinuria and changes of focal segmental glomerulosclerosis when biopsied. End-stage kidney disease (ESKD) is observed in 20% of carriers, at ages 50-70.

Familial C3 glomerulopathy associated with CFHR5 mutations: clinical characteristics of 91 patients in 16 pedigrees.

Background And Objectives: Complement factor H and related proteins (CFHR) are key regulators of the alternative complement pathway, where loss of function mutations lead to a glomerulopathy with isolated mesangial C3 deposits without immunoglobulins. Gale et al. (12) reported on 26 patients with the first familial, hematuric glomerulopathy caused by a founder mutation in the CFHR5 gene in patients of Cypriot descent living in the United Kingdom.

Founder mutations in the ATP6V1B1 gene explain most Cypriot cases of distal renal tubular acidosis: first prenatal diagnosis.

Aims: To investigate clinically and genetically all the distal renal tubular acidosis (dRTA) cases in Cyprus, to study one more family from Greece and to perform the first dRTA prenatal diagnosis. We also tried to find any association with sensorineural hearing loss (SNHL) onset and particular mutations.

Methods: Nine dRTA families from Cyprus and one from Greece were analyzed for mutations in ATP6V1B1 gene by DNA resequencing and PCR-RFLPs.

Identification of a mutation in complement factor H-related protein 5 in patients of Cypriot origin with glomerulonephritis.

Background: Complement is a key component of the innate immune system, and variation in genes that regulate its activation is associated with renal and other disease. We aimed to establish the genetic basis for a familial disorder of complement regulation associated with persistent microscopic haematuria, recurrent macroscopic haematuria, glomerulonephritis, and progressive renal failure.

Methods: We sought patients from the West London Renal and Transplant Centre (London, UK) with unusual renal disease and affected family members as a method of identification of new genetic causes of kidney disease.

Clinico-pathological correlations in 127 patients in 11 large pedigrees, segregating one of three heterozygous mutations in the COL4A3/ COL4A4 genes associated with familial haematuria and significant late progression to proteinuria and chronic kidney disease from focal segmental glomerulosclerosis.

Background: Heterozygous mutations in the COL4A3/ COL4A4 genes are currently thought to be responsible for familial benign microscopic haematuria and maintenance of normal long-term kidney function.

Methods: We report on 11 large Cypriot pedigrees with three such mutations. A total of 236 at-risk family members were genetically studied, and 127 (53.

COL4A3/COL4A4 mutations producing focal segmental glomerulosclerosis and renal failure in thin basement membrane nephropathy.

Mutations in the COL4A3/COL4A4 genes of type IV collagen have been found in approximately 40% of cases of thin basement membrane nephropathy, which is characterized by microscopic hematuria and is classically thought to cause proteinuria and chronic renal failure rarely. Here we report our observations of 116 subjects from 13 Cypriot families clinically affected with thin basement membrane nephropathy. These families first came to our attention because they segregated microscopic hematuria, mild proteinuria, and variable degrees of renal impairment, but a dual diagnosis of focal segmental glomerulosclerosis (FSGS) and thin basement membrane nephropathy was made in 20 biopsied cases.

A family with the branchio-oto-renal syndrome: clinical and genetic correlations.

Background: The branchio-oto-renal (BOR) syndrome is an autosomal dominant disease characterized by hearing loss of early onset, preauricular pits, branchial clefts, and early progressive chronic renal failure in up to 40% of family affected members. So far, it has not received due attention in the adult European nephrology literature and because of the combination of deafness with chronic renal failure it may be confused with the Alport syndrome. The BOR syndrome is caused by mutations in the EYA1 gene that maps on chromosome 8q13.