Barakat syndrome.

Barakat syndrome, also known as HDR syndrome, is a clinically heterogenous, autosomal dominant rare genetic disease, which frequency is unknown. It is primarily caused by deletion of chromosome 10p14 or mutation of GATA3 gene, located on chromosome 10. Although this syndrome is phenotypically defined by its triad of HDR: hypoparathyroidism (H), deafness (D), renal disease (R), the literature identifies cases with different components, consisting of HD, DR, HR (1). The syndrome was first described by Amin J. Barakat et al. in 1977 in siblings with hypocalcemia and proteinuria (2). So far, about 180 cases have been reported in the worldwide medical literature (3). In this report we present our own case report of patient with Barakat syndrome with hypoparathyrodism, unilateral deafness and renal impairment.

A case of HDR syndrome coexisting with tetralogy of Fallot, with a novel GATA3 mutation, which manifested as a renal abscess.

HDR syndrome is characterized by the triad of primary hypoparathyroidism, sensorineural hearing loss and renal malformation with widely variable manifestations. It is an autosomal dominant inherited disease caused by a mutation of the GATA3 (NM_001002295.2), which is located on chromosome 10p14. Congenital heart disease, such as tetralogy of Fallot, a typical complication of DiGeorge syndrome, is a rare complication of HDR syndrome. We herein report a case of HDR syndrome coexisting tetralogy of Fallot with a novel mutation, c.964C > T (p.Gln322*). This case suggested that the screening of renal involvement should be carefully performed in patients with a phenotypic combination of hypoparathyroidism and sensorineural hearing loss, to facilitate the early diagnosis of HDR syndrome. In addition, when the deletion of chromosome 22q11.2 is not detected by a fluorescence in situ hybridization analysis in patients exhibiting the partial phenotype of DiGeorge syndrome, the possibility of HDR syndrome should be considered and the renal function should be repeatedly evaluated.

Early Nephrosis Detection Based on Deep Learning with Clinical Time-Series Data.

Nephrosis is disease characterized by abnormal protein loss from impaired kidney. We constructed early prediction model using machine learning from clinical time series data, that can predict onset of nephrosis for more than one month. Long short-term memory capable of recognizing temporal sequential data patterns, was adopted as early prediction model for nephrosis. We verified our proposed prediction model has higher accuracy compared with those of baseline classifiers by 5-fold cross validation.

Novel homozygous OSGEP gene pathogenic variants in two unrelated patients with Galloway-Mowat syndrome: case report and review of the literature.

BACKGROUND: Galloway-Mowat syndrome (GAMOS) is a rare autosomal recessive disorder characterized by early-onset nephrotic syndrome and microcephaly with brain anomalies. WDR73 pathogenic variants were described as the first genetic cause of GAMOS and, very recently, four novel causative genes, OSGEP, LAGE3, TP53RK, and TPRKB, have been identified. CASE PRESENTATION: We present the clinical and genetic characteristics of two unrelated infants with clinical suspicion of GAMOS who were born from consanguineous parents. Both patients showed a similar clinical presentation, with early-onset nephrotic syndrome, microcephaly, brain atrophy, developmental delay, axial hypotonia, and early fatality. We identified two novel likely disease-causing variants in the OSGEP gene. These two cases, in conjunction with the findings of a literature review, indicate that OSGEP pathogenic variants are associated with an earlier onset of nephrotic syndrome and shorter life expectancy than WDR73 pathogenic variants. CONCLUSIONS: Our findings expand the spectrum of pathogenic variants in the OSGEP gene and, taken in conjunction with the results of the literature review, suggest that the OSGEP gene should be considered the main known monogenic cause of GAMOS. Early genetic diagnosis of GAMOS is of paramount importance for genetic counseling and family planning.

Panel sequencing distinguishes monogenic forms of nephritis from nephrosis in children.

BACKGROUND: Alport syndrome (AS) and atypical hemolytic-uremic syndrome (aHUS) are rare forms of chronic kidney disease (CKD) that can lead to a severe decline of renal function. Steroid-resistant nephrotic syndrome (SRNS) is more common than AS and aHUS and causes 10% of childhood-onset CKD. In recent years, multiple monogenic causes of AS, aHUS and SRNS have been identified, but their relative prevalence has yet to be studied together in a typical pediatric cohort of children with proteinuria and hematuria. We hypothesized that identification of causative mutations by whole exome sequencing (WES) in known monogenic nephritis and nephrosis genes would allow distinguishing nephritis from nephrosis in a typical pediatric group of patients with both proteinuria and hematuria at any level. METHODS: We therefore conducted an exon sequencing (WES) analysis for 11 AS, aHUS and thrombotic thrombocytopenic purpura-causing genes in an international cohort of 371 patients from 362 families presenting with both proteinuria and hematuria before age 25 years. In parallel, we conducted either WES or high-throughput exon sequencing for 23 SRNS-causing genes in all patients. RESULTS: We detected pathogenic mutations in 18 of the 34 genes analyzed, leading to a molecular diagnosis in 14.1% of families (51 of 362). Disease-causing mutations were detected in 3 AS-causing genes (4.7%), 3 aHUS-causing genes (1.4%) and 12 NS-causing genes (8.0%). We observed a much higher mutation detection rate for monogenic forms of CKD in consanguineous families (35.7% versus 10.1%). CONCLUSIONS: We present the first estimate of relative frequency of inherited AS, aHUS and NS in a typical pediatric cohort with proteinuria and hematuria. Important therapeutic and preventative measures may result from mutational analysis in individuals with proteinuria and hematuria.

Familial congenital choanal atresia with GATA3 associated hypoparathyroidism-deafness-renal dysplasia syndrome unidentified on auditory brainstem response.

Hypoparathyroidism-deafness-renal dysplasia (HDR) syndrome is a rare autosomal dominant disorder primarily caused by GATA3 haploinsufficiency and is challenging to diagnose in early childhood. We report a Japanese family with HDR syndrome and congenital choanal atresia. The 6-year-old female proband was diagnosed with epilepsy at the age of three. Under carbamazepine monotherapy, the patient presented hypoparathyroidism accompanied by severe hypocalcemia. Subsequently, renal ultrasound analysis revealed bilateral multicystic dysplastic kidneys. Because she had difficulty hearing, we sequenced GATA3 and determined that she had a c.708_709insC (p.Ser237Glnfs*66) allelic variant in exon 3. As a result, we found a family of this disease. Each family member, including her grandfather, mother, and two siblings, had HDR syndrome of varying clinical penetrance. We found a craniofacial anomaly, congenital choanal atresia, which was inherited as an autosomal dominant trait. Hypocalcemia coupled with vitamin D deficiency, triggered by carbamazepine treatment, ultimately revealed the proband's childhood- onset HDR syndrome. Pure-tone audiometry revealed different severities of deafness as well as the progression of sensory hearing loss. However, auditory brainstem response for hearing screening is probably insufficient for ascertaining HDR syndrome in the early stages of life. We presented new clinical clues to diagnose the HDR syndrome.

A Unique Genomic Variant of HDR Syndrome in Newborn.

BACKGROUND: HDR syndrome (also known as Barakat syndrome) is a rare genetic disorder due to deletions/mutations on specific regions of zinc-finger transcription factor (GATA3) gene. CASE CHARACTERISTICS: A male preterm infant presented with multiple dysmorphic features characterized by small for gestational age, hypognathia and facial abnormalities. OBSERVATION: Investigations revealed hypocalcemia and low parathyroid hormone levels and bilateral sensorineural deafness. OUTCOME: Chromosomal microarray analysis revealed a combination of deletion on chromosome 10p (10p15.3p14) with loss of GATA3 gene and duplication of chromosome 20p (20p13p12.3) as a result of unbalanced 10:20 translocation. MESSAGE: Detecting this syndrome at neonatal age is very important because it allows early intervention to minimize future clinical problems.

Extending the ophthalmological phenotype of Galloway-Mowat syndrome with distinct retinal dysfunction: a report and review of ocular findings.

BACKGROUND: Galloway-Mowat syndrome (GMS) is a rare autosomal recessive condition first described in 1968 and characterized by microcephaly and infantile onset of central nervous system (CNS) abnormalities resulting in severely delayed psychomotor development, cerebellar atrophy, epilepsy, and ataxia, as well as renal abnormalities such as nephrotic syndrome, proteinuria, end-stage renal disease (ESRD), and hiatal hernia. CASE PRESENTATION: We describe a GMS case diagnosed with homozygous missense mutation in the WDR73 gene, with absence of renal abnormalities. We expanded the clinical phenotype of GMS with WDR73 gene defect to include retinal dysfunction with missense mutation and developmental dysplasia of the hip. We compared eye findings of our case to previously reported cases, and we present an electroretinogram (ERG) picture for the first time in the literature. CONCLUSION: We recommend that clinicians screen patients with GM syndrome for retinal dysfunction and that a skeletal survey should be done to detect developmental dysplasia of the hip (DDH) so as to provide for early intervention.

Barakat syndrome revisited.

Barakat syndrome also known as HDR syndrome (Online Mendelian Inheritance in Man [OMIM] 146255), was first described by Barakat et al. in . It is a rare genetic disorder characterized by the triad of hypoparathyroidism "H," sensorineural deafness "D," and renal disease "R." The defect is caused by deletions in chromosome 10p14 or mutations in the GATA3 gene. Although the syndrome has been phenotypically defined by this triad the literature identifies cases with different components with, or without GATA3 defects making the definition of the syndrome confusing. We analyzed 180 cases and attempted to define the phenotype of the syndrome and suggest guidelines for diagnosis. We suggest that the diagnosis could be confirmed in patients who have all three components, and in those who have two components with a positive family history. GATA3 testing is optional to establish the diagnosis in these patients. The syndrome should be considered in patients with isolated "D" where other causes of "D" have been excluded and those with isolated "R," especially if there is family history of any of these components. In these instances, confirmatory GATA3 testing is indicated to confirm the diagnosis. In patients with nonsurgical "H," where "D" and "R" have been conclusively ruled out GATA3 studies are not needed as none of these patients were shown to be GATA3 haploinsufficient. Only 64.4% of patients in our review had "HDR." Some findings might have not been recognized or may could have appeared later in life, but it is evident that this syndrome is genotypically heterogeneous.

The relationship between glomerular function and podocyte structure of pre-proteinuria and acute nephrosis in puromycin aminonucleoside-induced rat models: a comparative electron microscopic study.

Puromycin aminonucleoside (PA) has been generally utilized as model of podocyte injury followed by massive proteinuria, severe damage on endocytotic activity of epithelial cells and postmodification of endocytosed compounds. However, total PA nephrosis (PAN) mechanism cannot be understood. We aimed to study glomerular function, foot process degeneration and transport pathways of podocytes in pre-proteinuria and acute PAN rats. Eighteen male Wistar albino rats were divided into three groups: control, pre-proteinuria and acute nephrosis groups (n=6). PA was injected into pre-proteinuria group for three times and acute group for nine times. Proteinuria levels in urine, creatinine and albumin levels in blood were detected 24 hours after PA injections. Renal cortex samples were prepared for transmission electron microscopy. Proteinuria levels in acute group significantly elevated, whereas creatinine clearance, serum albumin levels and urine volumes diminished compared to control and pre-proteinuria groups. In pre-proteinuria group, hypertrophy and structurally rich cytoplasm were detected only within podocytes. Acute group had various protein absorption granules secreted from podocyte cytoplasm to the urinary space through exocytosis after lysosomal digestion; but not observed in pre-proteinuria group. The number of slit pores in pre-proteinuria group decreased, particularly related to fusion of foot processes, subsequently leading to proteinuria. We concluded that foot process fusion begins prior to development of proteinuria although their serum albumin and creatinine clearance levels do not differ significantly. Additionally, we suggested that in acute PAN, first affected glomerular cells could be podocytes and there could be a correlation between glomerular function and number of slit pores.

HDR syndrome with a novel mutation in GATA3 mimicking a congenital X-linked stapes gusher: a case report.

BACKGROUND: Hypoparathyroidism, sensorineural hearing loss, and renal disease (HDR) syndrome, also known as Barakat syndrome, is a rare genetic disorder with high phenotypic heterogeneity caused by haploinsufficiency of the GATA3 gene on chromosome 10p14-p15. For these reasons, the diagnosis of HDR syndrome is challenging and requires a high index of suspicion as well as genetic analysis. CASE PRESENTATION: A 14-month-old boy, with sensorineural hearing loss in both ears, showed typical radiological features of X-linked stapes gusher on preoperative temporal bone computed tomography (CT) for cochlear implantations. Then after his discharge from hospital, he suffered a hypocalcemic seizure and we discovered a renal cyst during investigation of hypocalcemia. He was finally diagnosed with HDR syndrome by clinical findings, which were confirmed by molecular genetic testing. Direct sequencing of the GATA3 gene showed a heterozygous 2-bp deletion (c.1201_1202delAT), which is predicted to cause a frameshift of the reading frame (p.Met401Valfs*106). CONCLUSIONS: To our knowledge, this is the first case of HDR syndrome with a novel de novo variant mimicking a congenital X-linked stapes gusher syndrome. Novel mutations and the diversity of clinical manifestations expand the genotypic and phenotypic spectrum of HDR syndrome. Diagnosis of HDR syndrome is still challenging, but clinicians should consider it in their differential diagnosis for children with a wide range of clinical manifestations including hypocalcemia induced seizures and deafness. We hope that this case will contribute to further understanding and studies of HDR-associated GATA3 mutations.

Galloway-mowat syndrome - unusual form of nephrotic syndrome in adolescent.

Galloway-Mowat syndrome (GMS), also acknowledged as Microcephaly-Hiatal hernia nephrotic syndrome, is an uncommon genetic disorder inherited as an autosomal recessive trait usually seen before two years of life. It is an exceptional multisystem genetic disorder with a collection of skeletal, neurological, facial, gastrointestinal, growth, and renal abnormalities. This case report describes GMS in a girl, suffering from developmental delay, stunted growth, and various dysmorphic features, in whom nephrotic syndrome became apparent at adolescent age.

Idiopathic nephrotic syndrome in South African children.

BACKGROUND: Different histo-pathological types and treatment response patterns of Idiopathic nephrotic syndrome (INS) have been associated with differences in ethnicity and geographical location. OBJECTIVE: To provide an update on the steroid response and renal histo-pathological pattern in children treated for INS. METHOD: Medical records of children with INS treated at the Charlotte Maxeke Johannesburg Academic Hospital were reviewed. RESULTS: Mean age was 5.3 years ± 2.8. The majority (68.1%) of the 163 children were of the black racial group. The highest rate of INS was seen in the 2-6 year age group (71.2%). The black racial group had the highest rate (42/111; 37.8%) of focal segmental glomerulosclerosis (FSGS), and the white race had the highest rate (9/14; 64.3%) of minimal change disease (MCD). Ninety four (57.7%) patients were steroid sensitive (SSNS) while 69 patients (42.3%) were steroid resistant (SRNS). Minimal change disease was the most common histo-pathological type seen in SSNS (60%), while FSGS was the most common observed in patients who had SRNS (65.2%). CONCLUSION: There appears to be a higher rate of FSGS in all the racial groups, and also a higher rate of MCD in the black race group, when compared to previous reports.

[Bile salt nephropathy/cholemic nephrosis]. / Néphropathie à cristaux biliaires/néphropathie cholémique.

Bile cast nephropathy is a tubulo-interstitial nephropathy. Its diagnosis may be under-estimated. It develops in patients who have cholestatic jaundice, with high bilirubinemia. Bile salts are freely filtered through glomerulus. Under certain circumstances, it forms casts into the tubule and cause an acute tubular necrosis. The diagnosis evidence is histologic, but fulfilment of renal biopsy is often made difficult, because of the hemostatic abnormalities that patients with hepatocellular injury develop. The treatment is supportive and etiological. We report here the case of a patient who presented a drug-induced hepatic jaundice, complicated with acute kidney failure secondary to bile cast nephropathy. We present the histological diagnosis evidence.

Protein creatinine index: A possible predictor of nephropathy in hypertensives, in Northern India.

BACKGROUND: >33% of the hypertensive Indians develops nephropathy. Proteinuria is an early indicator of nephropathy. Gold standard for determining proteinuria is 24-hour urinary protein excretion which is a troublesome task with poor patient compliance. Protein creatinine index (PCI) in a random urine sample has been advocated by some researchers as an alternative approach. Aim of this study was to evaluate the association of PCI with the severity and duration of hypertension, in North Indian population. METHODS: 120 Stage-1 hypertensives, 120 stage-2 hypertensives, 40 pre-hypertensives and 40 normotensives were included in this study. 240 Hypertensive subjects were divided into 3 sub-groups based on duration: <5years (n=80), 5-10years (n=80) and >10years (n=80). Urinary protein was estimated by sulfosalicylic acid method and urinary creatinine was measured using modified Jaffe's method. PCI was measured as described by Shaw et al. Data was statistically analyzed by ANOVA and Pearson's correlation test using SPSS v20. RESULTS: PCI of stage-2 hypertensives (157.83±51.53) was significantly higher than normo-, pre- and stage-1 hypertensives. PCI of stage-1 hypertensives (134.15±46.04) was significantly higher than normotensives only. PCI of hypertensives for 5-10years (137.29±49.55) and >10years (181.85±47.42) was significant higher than controls and pre-hypertensives. PCI showed significantly stronger association with severity (r=0.595) and duration (r=0.745) of hypertension as compared to urinary protein and creatinine concentration. Data also suggest that the risk of renal injuries against the backdrop of raised blood pressure (BP) increases after 5years of hypertension. CONCLUSION: PCI can be used as a screening tool for early detection of hypertensive nephropathy. PCI monitoring should be incorporated in the routine checkup module of patients suffering from hypertension for >5years.

Expansion of phenotype and genotypic data in CRB2-related syndrome.

Sequence variants in CRB2 cause a syndrome with greatly elevated maternal serum alpha-fetoprotein and amniotic fluid alpha-fetoprotein levels, cerebral ventriculomegaly and renal findings similar to Finnish congenital nephrosis. All reported patients have been homozygotes or compound heterozygotes for sequence variants in the Crumbs, Drosophila, Homolog of, 2 (CRB2) genes. Variants affecting CRB2 function have also been identified in four families with steroid resistant nephrotic syndrome, but without any other known systemic findings. We ascertained five, previously unreported individuals with biallelic variants in CRB2 that were predicted to affect function. We compiled the clinical features of reported cases and reviewed available literature for cases with features suggestive of CRB2-related syndrome in order to better understand the phenotypic and genotypic manifestations. Phenotypic analyses showed that ventriculomegaly was a common clinical manifestation (9/11 confirmed cases), in contrast to the original reports, in which patients were ascertained due to renal disease. Two children had minor eye findings and one was diagnosed with a B-cell lymphoma. Further genetic analysis identified one family with two affected siblings who were both heterozygous for a variant in NPHS2 predicted to affect function and separate families with sequence variants in NPHS4 and BBS7 in addition to the CRB2 variants. Our report expands the clinical phenotype of CRB2-related syndrome and establishes ventriculomegaly and hydrocephalus as frequent manifestations. We found additional sequence variants in genes involved in kidney development and ciliopathies in patients with CRB2-related syndrome, suggesting that these variants may modify the phenotype.