Genetics of kidney disorders in Phelan-McDermid syndrome: evidence from 357 registry participants.

BACKGROUND: Phelan-McDermid syndrome (PMS) is a rare genetic disorder caused by SHANK3 pathogenic variants or chromosomal rearrangements affecting the chromosome 22q13 region. Previous research found that kidney disorders, primarily congenital anomalies of the kidney and urinary tract, are common in people with PMS, yet research into candidate genes has been hampered by small study sizes and lack of attention to these problems. METHODS: We used a cohort of 357 people from the Phelan-McDermid Syndrome Foundation International Registry to investigate the prevalence of kidney disorders in PMS using a cross-sectional design and to identify 22q13 genes contributing to these disorders. RESULTS: Kidney disorders reported included vesicoureteral reflux (n = 37), hydronephrosis (n = 36), dysplastic kidneys (n = 19), increased kidney size (n = 19), polycystic kidneys (15 cases), and kidney stones (n = 4). Out of 315 subjects with a 22q13 deletion, 101 (32%) had at least one kidney disorder, while only one out of 42 (2%) individuals with a SHANK3 pathogenic variant had a kidney disorder (increased kidney size). We identified two genomic regions that were significantly associated with having a kidney disorder with the peak associations observed near positions approximately 5 Mb and 400 Kb from the telomere. CONCLUSIONS: The candidate genes for kidney disorders include FBLN1, WNT7B, UPK3A, CELSR1, and PLXNB2. This study demonstrates the utility of patient registries for uncovering genetic contributions to rare diseases. Future work should focus on functional studies for these genes to assess their potential pathogenic contribution to the different subsets of kidney disorders.

Prenatal diagnosis of polycystic renal diseases: diagnostic yield, novel disease-causing variants, and genotype-phenotype correlations.

BACKGROUND: Polycystic renal disease is a frequent congenital anomaly of the kidneys, but research using chromosomal microarray analysis and exome sequencing in fetuses with polycystic renal disease remains sparse, with most studies focusing on the multisystem or genitourinary system. OBJECTIVE: This study aimed to assess the detection rate of detectable genetic causes of fetal polycystic renal disease at different levels, novel disease-causing variants, and genotype-phenotype correlations. STUDY DESIGN: This study included 220 fetal polycystic renal disease cases from January 2014 to June 2022. Cases were divided into the following 3 groups: isolated multicystic dysplastic kidneys, nonisolated multicystic dysplastic kidneys, and suspected polycystic kidney disease group. We reviewed data on maternal demographics, ultrasonographic results, chromosomal microarray analysis/exome sequencing results, and pregnancy outcomes. RESULTS: In our cohort, chromosomal microarray analysis identified 19 (8.6%) fetuses carrying chromosomal abnormalities, and the most common copy number variation was 17q12 microdeletion (7/220; 3.2%). Furthermore, 94 families chose to perform trio-exome sequencing testing, and 21 fetuses (22.3%) were found to harbor pathogenic/likely pathogenic variants. There was a significant difference in the live birth rate among the 3 groups (91/130 vs 46/80 vs 1/10; P<.001). Among 138 live birth cases, 106 (78.5%) underwent postnatal ultrasound review, of which 95 (89.6%) had a consistent prenatal-postnatal ultrasound diagnosis. CONCLUSION: For both isolated and nonisolated polycystic renal disease, our data showed high detection efficiency with both testing tools. The detection of novel pathogenic variants expands the known disease spectrum of polycystic renal disease-associated genes while enriching our understanding of the genotype-phenotype correlation. Therefore, we consider it feasible to perform chromosomal microarray analysis+exome sequencing testing in fetal polycystic renal disease. Moreover, prenatal-postnatal ultrasound concordance was greater, the live birth rate was higher, and prognosis was better when known genetic disorders were excluded, indicating that genetic testing results significantly influenced pregnancy decisions.

Prevalence of polycystic kidney disease in Persian and Persian-related cats in western Mexico.

OBJECTIVES: Autosomal dominant polycystic kidney disease (ADPKD), the most frequently diagnosed hereditary disease affecting Persian cats, is caused by a cytosine-to-adenine transversion (10063C>A) in PKD1, the gene that codes for polycystin-1. The objective of this study was to provide a preliminary estimate of the frequency of the pathogenic 10063C>A single nucleotide polymorphism (SNP) of PKD1 in Persian and Persian-related cat breeds in western Mexico. METHODS: Blood samples were collected from 104 cats (89 Persian, seven Persian crossbreed, five Siamese and three Himalayan cats). Genotyping was performed with our proposed PCR restriction fragment length polymorphism (RFLP) assay, as well as a previously established PCR-RFLP method for validation. The genotypes of control cats were corroborated by a commercial veterinary genetics laboratory. RESULTS: Our proposed PCR-RFLP assay and the validated PCR-RFLP methodology indicated that 24/104 (23.1%) cats in this study were heterozygous carriers of the 10063C>A SNP, including 23/89 Persian cats (25.8%) and 1/7 Persian crossbreed cats (14.3%). No Siamese or Himalayan cats were carriers. There were no discrepancies between the results obtained with our proposed assay and those obtained with the validation method or with commercial laboratory results. CONCLUSIONS AND RELEVANCE: The carrier frequency of the PKD1 10063C>A SNP in Persian and Persian-related cat breeds in western Mexico was found to be 23.1%. ADPKD frequencies among cat populations in Mexico have not been published previously. Genotyping assays can be used to facilitate the selection of breeding stocks by local breeders and veterinarians to avoid propagation of ADPKD.

Diagnosis and risk factors for intracranial aneurysms in autosomal polycystic kidney disease: a cross-sectional study from the Genkyst cohort.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is associated with an increased risk for developing intracranial aneurysms (IAs). We aimed to evaluate the frequency of diagnosis of IAs in the cross-sectional, population-based, Genkyst cohort, to describe ADPKD-associated IAs and to analyse the risk factors associated with the occurrence of IAs in ADPKD patients. METHODS: A cross-sectional study was performed in 26 nephrology centres from the western part of France. All patients underwent genetic testing for PKD1/PKD2 and other cystogenes. RESULTS: Among the 2449 Genkyst participants, 114 (4.65%) had a previous diagnosis of ruptured or unruptured IAs at inclusion, and ∼47% of them had a positive familial history for IAs. Most aneurysms were small and saccular and located in the anterior circulation; 26.3% of the patients had multiple IAs. The cumulative probabilities of a previous diagnosis of IAs were 3.9%, 6.2% and 8.1% at 50, 60 and 70 years, respectively. While this risk appeared to be similar in male and female individuals <50 years, after that age, the risk continued to increase more markedly in female patients, reaching 10.8% versus 5.4% at 70 years. The diagnosis rate of IAs was >2-fold higher in PKD1 compared with PKD2, with no influence of PKD1 mutation type or location. In multivariate analysis, female sex, hypertension <35 years, smoking and PKD1 genotype were associated with an increased risk for diagnosis of IAs. CONCLUSIONS: This study presents epidemiological data reflecting real-life clinical practice. The increased risk for IAs in postmenopausal women suggests a possible protective role of oestrogen.

Polycystic kidney disease increases the stoke incidence in Taiwan: A retrospective population-based cohort study using National Health Insurance Database.

BACKGROUND: Few studies documented incidence rates of different types of stroke among patients with polycystic kidney disease (PKD). METHODS: We conducted a retrospective cohort study based on the National Health Insurance (NHI) Database of Taiwan. The PKD cohort comprised patients aged≥20 years diagnosed with PKD using inpatient claims from 1998 to 2011, excluding prior stroke. The reference cohort was established by inpatients without PKD using 1:4 frequency-matched with age, gender, and baseline comorbidities. The two cohorts were followed-up until stroke hospitalization, death, withdrawal from the NHI program, or the end of 2012. To account for competing risks of death, we used multivariable competing risks regression models to estimate sub-distribution hazard ratio (SHR) adjusted for age, gender, baseline comorbidities and end stage renal disease. RESULTS: 7837 PKD patients and 31,211 reference subjects were followed up through 2012. A total of 955 cases of stroke were identified in the PKD cohort, including 441 ischemic stroke (IS), 289 intracranial hemorrhage (ICH), 73 subarachnoid hemorrhage (SAH) and 232 other stroke. The incidence rates of overall stroke, IS, ICH, and SAH were 21.3, 10.2, 6.8, and 1.7 per 1000 person-years, respectively. The SHR for overall stroke was 1.39 [95% confidence interval (CI) 1.28-1.50]. SAH had the highest SHR, 4.55 [95% CI 3.26-6.37], followed by ICH (1.84), other stroke (1.24), and IS (1.22). CONCLUSION: This study illustrated the incidence rates of stroke among inpatient of PKD. The PKD patients had a significantly increased risk of all kinds of stroke after adjusting baseline comorbidities.

Etiology and impact on outcomes of polycystic kidney disease in abdominal aortic aneurysm.

PURPOSE: We investigated the etiology and impact on outcomes of polycystic kidney disease in patients with abdominal aortic aneurysm. METHODS: Eight-hundred patients who underwent open (n = 603) or endovascular aortic repair (n = 197) were divided into three groups: no cyst (n = 204), non-polycystic kidney (n = 503), and polycystic kidney (≥ 5 cysts in the bilateral kidneys, n = 93). The characteristics and outcomes were compared among the groups. RESULTS: In the polycystic kidney group, the age was increased and the proportions of patients with male sex, hypertension, and estimated glomerular filtration rate < 30 mL/min/1.73 m2 were greater. The overall hospital mortality rates were similar. The incidence of acute kidney injury after elective open aortic repair was increased in the polycystic kidney group (12%, 17%, and 29%, P = 0.020). In the polycystic kidney group, 80 patients did not have renal enlargement or a family history of renal disease, while 13 (corresponding to 1.6% [13/800] of the overall patients), had renal enlargement, suggesting the possibility of hereditary polycystic kidney disease. CONCLUSIONS: In our cohort, 1.6% of the patients with abdominal aortic aneurysm who underwent surgery were at risk of hereditary polycystic kidney disease. Polycystic kidney disease was associated with acute kidney injury after open aortic repair.

Pathologic characterization of renal epithelial neoplasms arising in nonfunctioning kidneys.

Nonfunctioning kidneys secondary to various etiologies display different histopathological features. Studies focused on incidence and types of renal neoplasms using the new World Health Organization and International Society of Urological Pathology classification system in various types of nonfunctioning kidneys are very limited. We identified 311 nephrectomies of nonfunctioning kidneys and categorized them into 5 categories: acquired cystic kidney disease (ACKD, n = 61); end-stage renal disease, nonspecific (ESRD, n = 63); adult polycystic kidney disease (APKD, n = 49); failed transplant kidney (FTK, n = 96); and those caused by obstructive conditions in the kidney (OCK, n = 42). ACKD (70%) and ESRD (43%) had higher cancer incidences than the other 3 groups (APKD = 2%, FTK = 0%, and OCK = 5%). Besides clear cell renal cell carcinoma (RCC) and papillary RCC, clear cell papillary RCC had a much higher incidence within ACKD patients (13/61) compared to other groups. ACKD-associated RCC was only identified in ACKD patients. ACKD patients had significantly longer dialysis duration compared to ESRD, APKD, and FTK. Although they had similar risk for clear cell RCC and papillary RCC, ACKD patients had a much higher risk for ACKD-associated RCC and clear cell papillary RCC than ESRD patients. Although most RCCs arising in these nonfunctioning kidneys were early pT1 stage, 6 ACKD patients and 3 ESRD patients had higher-stage diseases, which can be fatal if not treated appropriately. Therefore, precise clinicopathological classification of these nonfunctioning kidneys is important for predicting kidney cancer risk. These results indicate the need for active monitoring of the patients with high-risk nonfunctioning kidney diseases and appropriate surgical treatment when necessary.

Polycystic kidney disease.

Cystic kidneys are common causes of end-stage renal disease, both in children and in adults. Autosomal dominant polycystic kidney disease (ADPKD) and autosomal recessive polycystic kidney disease (ARPKD) are cilia-related disorders and the two main forms of monogenic cystic kidney diseases. ADPKD is a common disease that mostly presents in adults, whereas ARPKD is a rarer and often more severe form of polycystic kidney disease (PKD) that usually presents perinatally or in early childhood. Cell biological and clinical research approaches have expanded our knowledge of the pathogenesis of ADPKD and ARPKD and revealed some mechanistic overlap between them. A reduced 'dosage' of PKD proteins is thought to disturb cell homeostasis and converging signalling pathways, such as Ca2+, cAMP, mechanistic target of rapamycin, WNT, vascular endothelial growth factor and Hippo signalling, and could explain the more severe clinical course in some patients with PKD. Genetic diagnosis might benefit families and improve the clinical management of patients, which might be enhanced even further with emerging therapeutic options. However, many important questions about the pathogenesis of PKD remain. In this Primer, we provide an overview of the current knowledge of PKD and its treatment.

Congenital and acquired diseases related to stone formation.

PURPOSE OF REVIEW: To summarize the latest findings of congenital and acquired diseases related to stone formation and help understanding the multitude of cofactors related to urolithiasis. RECENT FINDINGS: Urolithiasis is related to a broad spectrum of congenital and acquired diseases and its management varies according to the stone type, underlying disease or recurrence rate, but it also changes according to recent findings and developments. As prevalence of urolithiasis is constantly increasing, identification of high-risk stone formers and early treatment is essential. Therefore, genetic evaluation like whole exome sequencing becomes a pertinent part of further diagnostics. SUMMARY: Stone formation is a very heterogeneous pathomechanism. This prompt us to look at every patient individually particularly in high-risk patients, including stone and 24-h-urine analysis and additional diagnostic work-up based on stone type or underlying disease.

Epidemiology of end-stage renal disease in Dubai: Single-center data.

Hemodialysis (HD) was first established in Dubai in the year 1980 and was in its full capacity by the year 1983. Since then, the HD population has been growing rapidly. This report represents the demographic data and clinical characteristics of our HD patients during the period between January 2012 and October 2016. Diabetic nephropathy (57%) and hypertension (12.4%) are emerging as the most common causes of end-stage renal disease (ESRD) in our data, followed by undetermined causes in those who presented as ESRD (10.9%), and then by rejected transplant in 4.6%. Obstructive uropathy in our data was 4.37% among all causes. The causes were primary glomerulonephritis (only proven cases in kidney biopsy were counted) in 3.6%, adult polycystic kidney disease in 2.43%, and lupus nephritis in 1.45% of cases. The prevalence of ESRD in the current study was 152 patients per million population per year.

First report of Polycystic kidney disease occurrence in Persian cats in Serbia.

Polycystic kidney disease (PKD) is an inherited autosomal disorder in cats, mostly diagnosed in Persian cats. Renal cysts can be diagnosed by ultrasound, but cats must be at least 16 weeks old. The goals of this study were to assess the occurrence of PKD in Serbia using a randomly selected group of Persian cats, to compare the diagnostic efficacy of ultrasound and genetic tests, and to measure haematological and selected biochemical parameters. We examined 70 cats of Persian breed, between 4 months and 8 years of age. Complete blood count and selected biochemical parameters were measured, renal ultrasound was performed. Swabs of the oral cavity were obtained for genetic testing. Percentage of PKD positive cats identified by genetic testing was 48.6%, whilst only 18.6% were detected through ultrasound. Animals that were polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) positive and ultrasound negative ranged from 4 months to 3.5 years. All haematological and biochemical parameters were within the the normal range values in all examined cats. Genetic methods proved to be the most effective for reliable and early diagnosis of PKD in Persian cats. DNA analysis can be used right after birth, and excludes the need for other diagnostic procedures, such as ultrasound.

Hepatorenal fibrocystic diseases in children.

BACKGROUND: Hepatorenal fibrocystic diseases (HRFCDs) are a group of monogenic disorders characterized by developmental abnormalities involving the liver and kidney. In this study, we performed genotype and phenotype analyses of children with HRFCDs to determine the distribution of underlying diseases. METHODS: A total of 36 children with HRFCDs were recruited, with genetic tests being performed in 22 patients and 14 patients diagnosed clinically as having autosomal recessive polycystic kidney disease (ARPKD). RESULTS: In children with HRFCDs, ARPKD was the most common disease, found in 16/36 (44.4 %), followed by nephronophthisis 13 (NPHP13) in 11/36 (30.6 %) and Meckel-Gruber syndrome type 3 (MKS3) in 4/36 (11.1 %). Renal function deteriorated faster in children with NPHP13. The main hepatic pathology was Caroli disease in the NPHP13 patients, while most other patients had Caroli syndrome or congenital hepatic fibrosis. Of note, three of four MKS3 patients had an accompanying choledochal cyst. No ARPKD patient had other organ involvement, while several NPHP13 patients had ocular and/or neurodevelopmental involvement. In contrast, all MKS3 patients had severe ocular and neurodevelopmental involvement. CONCLUSIONS: NPHP13 is a major disease in the HRFCD category, and thorough evaluation of its clinical features, including kidney, liver and other organ involvement, may aid in the differential diagnosis of HRFCD.

Meckel-Gruber Syndrome: a population-based study on prevalence, prenatal diagnosis, clinical features, and survival in Europe.

Meckel-Gruber Syndrome is a rare autosomal recessive lethal ciliopathy characterized by the triad of cystic renal dysplasia, occipital encephalocele and postaxial polydactyly. We present the largest population-based epidemiological study to date using data provided by the European Surveillance of Congenital Anomalies (EUROCAT) network. The study population consisted of 191 cases of MKS identified between January 1990 and December 2011 in 34 European registries. The mean prevalence was 2.6 per 100,000 births in a subset of registries with good ascertainment. The prevalence was stable over time, but regional differences were observed. There were 145 (75.9%) terminations of pregnancy after prenatal diagnosis, 13 (6.8%) fetal deaths, 33 (17.3%) live births. In addition to cystic kidneys (97.7%), encephalocele (83.8%) and polydactyly (87.3%), frequent features include other central nervous system anomalies (51.4%), fibrotic/cystic changes of the liver (65.5% of cases with post mortem examination) and orofacial clefts (31.8%). Various other anomalies were present in 64 (37%) patients. As nowadays most patients are detected very early in pregnancy when liver or kidney changes may not yet be developed or may be difficult to assess, none of the anomalies should be considered obligatory for the diagnosis. Most cases (90.2%) are diagnosed prenatally at 14.3 ± 2.6 (range 11-36) gestational weeks and pregnancies are mainly terminated, reducing the number of LB to one-fifth of the total prevalence rate. Early diagnosis is important for timely counseling of affected couples regarding the option of pregnancy termination and prenatal genetic testing in future pregnancies.

Causes of mortality in anuran amphibians from an ex situ survival assurance colony in Panama.

The success of ex situ survival assurance populations as tools for amphibian conservation depends on the health and reproductive success of founder populations. Necropsy examination and histopathology of animals that die in assurance populations are useful for the identification of population-limiting disease problems and can help to direct applied research efforts in areas such as amphibian husbandry and nutrition. This study reviewed postmortem findings in 167 frogs from 13 species that died in a large Panamanian rescue and survival assurance population between 2006 and 2011. Common problems identified in long-term captive animals, especially in Atelopus species, were epithelial squamous metaplasia suggestive of vitamin A deficiency and a polycystic nephropathy resembling lesions seen in laboratory animals with electrolyte imbalances. Metabolic bone disease was a significant contributor to morbidity in captive-bred juvenile frogs of Gastrotheca cornuta, Hemiphractus fasciatus, and Hylomantis lemur. Findings common to multiple species included poor overall nutritional condition that was sometimes attributable to maladaptation to captive husbandry and epidermal hyperplasia and hyperkeratosis possibly reflecting environmental skin irritation. Infectious diseases and endoparasitism were most common in recently captured animals and included chytridiomycosis and Rhabdias sp. lungworms. Applied research efforts to improve sustainability of survival assurance populations should focus on elucidating optimal husbandry practices for diverse species, improving methods for nutritional supplementation of cultured insects and examination of the role of water composition in disease development.

Neonatal polycystic kidney disease.

This article provides an up-to-date comprehensive review and summary on neonatal polycystic kidney disease (PKD) with emphasis on the differential diagnosis, clinical manifestations, diagnostic techniques, and potential therapeutic approaches for the major causes of neonatal PKD, namely hereditary disease, including autosomal recessive and autosomal dominant PKD and nonhereditary PKD, with particular emphasis on multicystic dysplastic kidney. A brief overview of obstructive cystic dysplasia and simple and complex cysts is also included.

Filling the holes in cystic kidney disease research.

Kidney disease is a significant medical and public health problem. The National Institute of Diabetes and Digestive and Kidney Diseases recently asked the community to identify research objectives, which, if addressed, could improve understanding of basic kidney function and aid in prevention, treatment, and reversal of kidney disease. The Kidney Research National Dialogue invited interested parties to submit, discuss, and prioritize ideas using an interactive website; 1600 participants posted more than 300 ideas covering all areas of kidney disease, including the cystic kidney diseases. Although much is known about the genetics and pathogenesis of cystic diseases, there remain challenges to our understanding of the fundamental mechanisms of cyst formation, what genes act as modifiers to cause variable responses in different people, and how to detect and monitor disease progression. This article summarizes key research questions for cystic kidney diseases.

Prevalence and related factors of the absence of anemia among Chinese chronic hemodialysis patients: a multicenter cross-sectional study.

BACKGROUND: Some chronic hemodialysis (HD) patients can maintain normal hemoglobin levels without requiring erythropoiesis-stimulating agents (ESAs). However, the prevalence and the factors associated with this condition in Chinese chronic HD patients have not been reported. The aim of this study was to investigate clinical features, iron metabolism, and other characteristics to survey the prevalence rate and the related factors of this condition among Chinese chronic HD patients. METHODS: A total of 1,318 chronic HD patients participated in this study. The patients were classified into a non-ESA group (n = 11) and an ESA group (n = 1,307). The r-HuEPO-independent (non-ESA) HD patients were defined as having hemoglobin greater than 12 g/dl for more than 6 months without r-HuEPO injection, blood transfusion, or androgen therapy. Epidemiological and laboratory data were collected. Renal sonography was also performed on each patient to evaluate the formation of renal and liver cysts, and the number and size of the cysts were recorded. RESULTS: Approximately 0.84 % of all HD patients were found to be r-HuEPO independent. The non-ESA group had a higher proportion of men (79.6 vs. 58.3 %), a longer duration of renal replacement therapy (RRT) (8.6 ± 6.1 vs. 5.1 ± 3.3 years), a higher prevalence of adult polycystic kidney disease (APKD) (46.3 vs. 9.7 %), a higher prevalence of hepatitis C virus (HCV) liver disease (26.2 vs. 3.2 %, P < 0.01), and had older patients (63.3 ± 13.6 vs. 49.6 ± 13.5 years). Endogenous erythropoietin levels in the non-ESA group were significantly higher than those in the ESA group (61.8 ± 27.1 vs. 29.3 ± 11.7 mU/ml). Non-ESA patients had a significantly higher number of renal (38.1 vs. 13.2 %) and hepatic cysts (9.3 vs. 1.9 %), which were also larger in size (2.9 ± 1.6 vs. 1.3 ± 0.3 cm) compared with those of patients in the ESA group. No significant difference in iron metabolism was found between two groups. In the multivariate Cox analysis, the independent predictor factors for the absence of anemia in these HD patients were the number of renal cysts >6 cysts (95 % CI 1.058-1.405; P = 0.00), endogenous erythropoietin levels (95 % CI 1.139-1.361; P = 0.05), HCV+ liver disease (95 % CI 1.129-1.316; P = 0.01), and time on RRT (95 % CI 1.019-1.263; P = 0.05). CONCLUSIONS: To our knowledge, this study is the first to report on r-HuEPO independence among Chinese HD patients. The prevalence among Chinese chronic HD patients is significantly lower than that reported in the literature. Factors contributing to this condition are complex and multiple. The frequency of this condition is higher in men and in older patients with long-term RRT, in patients with HCV+ liver disease, and in APKD patients. This condition is associated with increased endogenous erythropoietin production and the presence of renal and hepatic cysts.

Arachnoid cysts in tuberous sclerosis complex.

OBJECTIVE: Some clinical findings in tuberous sclerosis complex (TSC), such as hypomelanotic macules or angiofibromas are related to problems in development of the neural crest, which is also the origin of cranial leptomeninges. Arachnoid cysts have been reported in two TSC patients to date. The purpose of this study was to assess the prevalence and characteristics of arachnoid cysts in a large cohort of TSC. MATERIALS AND METHOD: We performed a review of brain MRIs of 220 TSC patients searching for arachnoid cysts. RESULTS: Arachnoid cysts were found in 12 (5.5%) (general population: 0.5%), including ten males (83.3%). Four patients (33.3%) had also autosomal dominant polycystic kidney disease (ADPKD) due to a contiguous deletion of the TSC2-PKD1 genes. Three patients (25%) had two or more arachnoid cysts, of whom two also had ADPKD. One patient with an arachnoid cyst did not have tubers, subependymal nodules or white matter migration lines. CONCLUSION: Our study suggests that arachnoid cysts are part of the clinical spectrum of TSC and may be also present in TSC patients without other typical TSC brain lesions.

Nationwide survey of Arima syndrome: revised diagnostic criteria from epidemiological analysis.

AIM: We have never known any epidemiological study of Arima syndrome since it was first described in 1971. To investigate the number of Arima syndrome patients and clarify the clinical differences between Arima syndrome and Joubert syndrome, we performed the first nationwide survey of Arima syndrome, and herein report its results. Furthermore, we revised the diagnostic criteria for Arima syndrome. METHODS: As a primary survey, we sent out self-administered questionnaires to most of the Japanese hospitals with a pediatric clinic, and facilities for persons with severe motor and intellectual disabilities, inquiring as to the number of patients having symptoms of Arima syndrome, including severe psychomotor delay, agenesis or hypoplasia of cerebellar vermis, renal dysfunction, visual dysfunction and with or without ptosis-like appearance. Next, as the second survey, we sent out detailed clinical questionnaires to the institutes having patients with two or more typical symptoms. RESULTS: The response rate of the primary survey was 72.7% of hospitals with pediatric clinic, 63.5% of national hospitals and 66.7% of municipal and private facilities. The number of patients with 5 typical symptoms was 13 and that with 2-4 symptoms was 32. The response rate of the secondary survey was 52% (23 patients). After reviewing clinical features of 23 patients, we identified 7 Arima syndrome patients and 16 Joubert syndrome patients. Progressive renal dysfunction was noticed in all Arima syndrome patients, but in 33% of those with Joubert syndrome. CONCLUSION: It is sometimes difficult to distinguish Arima syndrome from Joubert syndrome. Some clinicians described a patient with Joubert syndrome and its complications of visual dysfunction and renal dysfunction, whose current diagnosis was Arima syndrome. Thus, the diagnosis of the two syndromes may be confused. Here, we revised the diagnostic criteria for Arima syndrome.