African American polycystic kidney patients receive higher risk kidneys, but do not face increased risk for graft failure or post-transplant mortality.

African Americans (AA) are disproportionately affected by end-stage renal disease (ESRD) and have worse outcomes following renal transplantation. Autosomal dominant polycystic kidney disease (ADPKD) is the most common genetic condition leading to ESRD necessitating transplant. We explored this population with respect to race by conducting a retrospective analysis of the UNOS database between 2005 and 2019. Our study included 10,842 (AA n = 1661; non-AA n = 9181) transplant recipients whose primary diagnosis was ADPKD. We further stratified the AA ADPKD population with respect to blood groups (AA blood type B n = 295 vs AA non-B blood type n = 1366), and also compared this cohort to AAs with a diagnosis of DM (n = 16,706) to identify unique trends in the ADPKD population. We analyzed recipient and donor characteristics, generated survival curves, and conducted multivariate analyses. African American ADPKD patients waited longer for transplants (924 days vs 747 days P < .001), and were more likely to be on dialysis (76% vs 62%; p < .001). This same group was also more likely to have AA donors (21% vs 9%; p < .001) and marginally higher KDPI kidneys (0.48 vs 0.45; p < .001). AA race was a risk factor for delayed graft function (DGF), increasing the chance of DGF by 45% (OR 1.45 95% CI 1.26-1.67; p < .001). AA race was not associated with graft failure (HR 1.10 95% CI 0.95-1.28; p = .21) or patient mortality (HR 0.84 95% CI 0.69-1.03; p = .09). Racial disparities exist in the ADPKD population. They should be continually studied and addressed to improve transplant equity.

Syndromic ciliopathies: From single gene to multi gene analysis by SNP arrays and next generation sequencing.

Joubert syndrome (JS) and related disorders (JSRD), Meckel syndrome (MKS) and Bardet-Biedl syndrome (BBS) are autosomal recessive ciliopathies with a broad clinical and genetic overlap. In our multiethnic cohort of 88 MKS, 61 JS/JSRD and 66 BBS families we performed genetic analyses and were able to determine mutation frequencies and detection rates for the most frequently mutated MKS genes. On the basis of determined mutation frequencies, a next generation gene panel for JS/JSRD and MKS was established. Furthermore 35 patients from 26 unrelated consanguineous families were investigated by SNP array-based homozygosity mapping and subsequent DNA sequencing of known candidate genes according to runs of homozygosity size in descending order. This led to the identification of the causative homozygous mutation in 62% of unrelated index cases. Based on our data we discuss various strategies for diagnostic mutation detection in the syndromic ciliopathies JS/JSRD, MKS and BBS.

Etiology of chronic renal failure in Jenin district, Palestine.

A study was conducted on chronic renal failure patients treated by medications or by hemodialysis at The Martyr Dr. Khalil Sulaiman Hospital in Jenin city, Palestine, from 1/8/2005 to 1/8/2006 to know the underlying etiology of chronic renal failure. The subjects included were 84 patients. The information was obtained from files of the patients. The diagnosis was based on medical history, laboratory tests, X-rays, CT scans, ultrasound and renal biopsies. The results showed that the three most common causes of chronic renal failure in Jenin district were diabetes mellitus (33.32%), hypertension (16.7%), and chronic glomerulonephritis (13.1%). Inherited kidney diseases formed an important percentage (17.85%) and included primary hyperoxaluria (10.71%), Alport's syndrome (5.95%), and adult polycystic kidney disease (1.19%). These results differ from what is found in most developing countries including many Arab countries where the principal causes of chronic renal failure are chronic glomerulonephritis and interstitial nephritis. The high prevalence of inherited kidney diseases in some families (primary hyperoxaluria and Alport's) syndrome may be explained by the very high prevalence of consanguineous marriage especially among cousins in these families.

Descriptive epidemiology of selected heritable birth defects in Texas.

BACKGROUND: Few population-based studies exist on descriptive epidemiologic characteristics of rare heritable birth defects. The number of birth defect cases in the Texas Birth Defects Registry (one of the largest active birth defects surveillance systems in the world) enabled us to examine six different heritable disorders (aqueductal stenosis, infantile polycystic kidney disease, achondroplasia, thanatophoric dwarfism, chondrodysplasia/dwarfism not otherwise specified (NOS), and osteogenesis imperfecta) for a variety of descriptive demographic variables. METHODS: The Texas Birth Defects Registry was used to identify infants or fetuses with heritable birth defects. Crude prevalence rates were calculated and Poisson regression was used to test the association of each demographic variable (e.g., maternal age) with each of the selected genetic birth defects. RESULTS: White non-Hispanics exhibited higher rates of achondroplasia and osteogenesis imperfecta than other race/ethnic groups. Lower maternal education level and to a lesser extent, paternal education level, was associated with higher rates of several disorders. The birth prevalence rate for achondroplasia decreased from 1999 through 2006. CONCLUSION: The use of a large birth defects registry provides a sufficient count of cases to perform some basic epidemiologic analysis on selected rare heritable birth defects.

Effect of ACE gene polymorphism on age at renal death in polycystic kidney disease in Japan.

Polycystic kidney disease (PKD) is one of the most common genetic disorders and a major cause of renal death or end-stage renal disease (ESRD) requiring regular hemodialysis. The responsible genes recently have been cloned; however, genetic factors influencing the rate of progression to ESRD in patients with PKD have yet to be defined. Several studies have shown increased activity of the renin-angiotensin system (RAS) in patients with PKD. In addition, genetic polymorphisms of the RAS have been associated with the development of cardiovascular diseases. Therefore, these polymorphisms are good candidates for disease-modifying genetic factors or markers in PKD. In two previous reports of white subjects with a cumulative survival analysis, it was suggested that patients with P:KD1 homozygous for the deletion allele of the angiotensin-converting enzyme (ACE) gene are at increased risk for early renal death. To confirm this hypothesis in Japanese subjects, 103 individuals with PKD were genotyped for several components of the RAS, ie, ACE insertion/deletion (I/D) polymorphism, angiotensinogen (AGT) M235T, and angiotensin II type 1 receptor (AT1) A1166C. Seventy-six of the 103 patients (73.8%) reached ESRD at an average age of 52.1 +/- 11.3 years. The frequencies of each genotype of the genes were similar to those expected from Hardy-Weinberg equilibrium. There was a tendency to an excess of patients homozygous for the D allele in patients with ESRD (DD in patients with ESRD, 11.8%; DD in patients without ESRD, 3.7%; chi-square, 1.505; P: = 0.22). Cumulative renal survival was significantly less in those with the DD genotype compared with ID/II genotypes. Estimated mean renal survival was 46.4 years (95% confidence interval, 39.5 to 53.3) in subjects with the DD genotype and 57.2 years (95% confidence interval, 54.2 to 60.2) in ID/II genotypes (chi-square, 7.76; P: = 0.0053). There was no association between age at onset of ESRD and either M235T or A1166C polymorphism. These findings suggest that Japanese patients with PKD homozygous for the D allele of the ACE gene are at increased risk for developing ESRD at an early age.

Autosomal dominant polycystic kidney disease in blacks: clinical course and effects of sickle-cell hemoglobin.

Autosomal dominant polycystic kidney disease (ADPKD) is a frequent cause of ESRD, but its frequency in blacks has not been well delineated and its course and the effects of sickle hemoglobin in this disease in blacks have not been previously reported. The occurrence of ADPKD in blacks and whites was determined in two ESRD populations: all ESRD patients seen over a 16-yr period in one area of Southeast Tennessee and all ESRD patients in 15 hemodialysis units in Tennessee and Atlanta, GA. The frequency of sickle hemoglobin was determined and compared in a group of nonrelated blacks with ESRD with and without ADPKD. The age at onset of ESRD and factors that might affect ADPKD such as gender, hypertension, and hemoglobin type were examined. ADPKD was a less frequent cause of ESRD in blacks than whites (1.4 versus 6.8%). However, after adjusting for the population rate, the incidence rates in blacks and whites were similar (0.48 and 0.47 of 100,000). There was a higher incidence of sickle hemoglobin in nonrelated blacks with ADPKD versus other black ESRD patients (50 versus 7.5%; P < 0.005). Blacks had an earlier onset of ESRD than whites (43.2 versus 55.4 yr; P < 0.0001), as did blacks with sickle-cell trait versus blacks without (38.2 versus 48.1 yr; P < 0.003). In this population, hypertension and gender had no effect on the onset of ESRD. ADPKD accounted for a smaller percentage of blacks than whites with ESRD because of the high percentage of blacks with renal disease from other causes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult polycystic kidney disease in a kindred of West Indian origin exhibits linkage with the 3'HVR probe on chromosome 16.

In a large pedigree of Caribbean origin with adult polycystic kidney disease, linkage has been established to the 3'HVR probe on chromosome 16. Although there are five different fathers in this pedigree, only one of whom was available for DNA analysis, the polymorphic nature of 3'HVR has enabled gene tracking to be carried out. The same allele cosegregates with the disease in every affected family member.

A new approach to the treatment of polycystic kidneys.

Maximum conservativism was the watchword up to 1979 in dealing with polycystic disease. In the period 1979 to 1985 a total of 45 patients were subjected to 80 instances of polycystic resection whereby larger cysts were removed by excision, smaller ones by ignipuncture, with particular attention to extirpation of the perihilar cysts. Post-operative incidence of hypertension dropped from 33 to 3%. The method described is rated as one of the feasible expedients to deal with polycystic disease in the early compensated stage.