Acute Kidney Injury in Pediatric Patients with COVID-19; Clinical Features and Outcome.

INTRODUCTION: Renal disorders have been reported as the underlying cause as well as complications of critical COVID-19 in pediatric patients. The purpose of this study was to investigate the pattern of kidney involvement, particularly acute kidney injury (AKI), among pediatric patients with COVID-19. METHODS: In this prospective study, hospitalized pediatric patients with a clinical diagnosis of COVID-19 were enrolled. Demographic, clinical, and laboratory findings were collected and analyzed using a mixed method of qualitative and quantitative approaches and descriptive statistics. RESULTS: One hundred and eighty-seven patients, including 120 (64.2%) males and 67 (35.8%) females with COVID-19 with a median age (interquartile range) of 60 (24 to 114) months were enrolled in this study. Most patients (n = 108, 58.1%) had one or two underlying comorbidities, mainly malnutrition (77.4%), neurologic/learning disorders (21.4%), and malignancy (10.2%). According to the Kidney Disease Improving Global Outcomes (KDIGO) classification, AKI was detected in 38.5% of patients (stage 1: 55.6%, stage 2: 36.1%, and stage 3: 8.3%) at presentation or during hospitalization. Nine patients (4.8%) required hemodialysis and 16 (8.6%) eventually died. There was no significant association between AKI and admission to the pediatric intensive care unit (PICU) (P > .05), a multisystem inflammatory syndrome in children (MIS-C) (P > .05), comorbidities (P > .05), and mortality rate (P > .05). CONCLUSION: Kidneys are among the major organs affected by COVID-19. Although kidney abnormalities resolve in the majority of pediatric COVID-19 infections, particular attention should be paid to serum creatinine and electrolyte levels in patients affected by COVID-19, particularly children with a history of malnutrition and kidney disorders.  DOI: 10.52547/ijkd.7151.

Revisiting the Management of Pediatric Kidney Transplants, A Multicenter Analysis

The newest Kidney Disease Improving Global Outcomes (KDIGO) guideline recommendations were investigated mainly for the care of adult kidney transplant recipients, but no guideline exists for the management of pediatric transplant recipients. This review provides update recommendations in the management of pediatric kidney transplantation. Four electronic databases, PubMed, EMBASE, Google Scholar, and Web of Science were searched systematically for the last two decades, using Mesh terms in English language. The Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach was used for grading the quality of the overall evidence and the strength of recommendations for each outcome across the studies. The overall quality of evidence categorized as high (A), moderate (B), low (C), or poor (D). The strength of a recommendation was determined as level 1 (recommended) or level 2 (suggested). The ungraded statements were determined on the basis of common sense to provide general advice. Of the 317 citations which were screened for the evidence review, 62 were included in data extraction. The included studies were randomized controlled trials, prospective cohorts and cross-sectional, descriptive, and review studies. Of the 115 statements, 56 (48.6%) were graded 1 (we recommend), 34 (29.5%) were graded 2 (we suggest), and 25 (21.7%) were ungraded statements. Altogether, only 22 (19.1%) of recommendations reached the "A" or "B" levels of quality of evidence. The pediatric kidney transplant recipients are different from adult recipients regarding the primary kidney diseases, surgical techniques, drug metabolism, adherence to medications, growth and neurocognitive development and immunization needs prior to transplantation.  DOI: 10.52547/ijkd.7179.

Oral Coenzyme Q10 supplementation leads to better preservation of kidney function in steroid-resistant nephrotic syndrome due to primary Coenzyme Q10 deficiency.

Primary Coenzyme Q10 (CoQ10) deficiency is an ultra-rare disorder caused by defects in genes involved in CoQ10 biosynthesis leading to multidrug-resistant nephrotic syndrome as the hallmark kidney manifestation. Promising early results have been reported anecdotally with oral CoQ10 supplementation. However, the long-term efficacy and optimal prescription remain to be established. In a global effort, we collected and analyzed information from 116 patients who received CoQ10 supplements for primary CoQ10 deficiency due to biallelic pathogenic variants in either the COQ2, COQ6 or COQ8B genes. Median duration of follow up on treatment was two years. The effect of treatment on proteinuria was assessed, and kidney survival was analyzed in 41 patients younger than 18 years with chronic kidney disease stage 1-4 at the start of treatment compared with that of an untreated cohort matched by genotype, age, kidney function, and proteinuria. CoQ10 supplementation was associated with a substantial and significant sustained reduction of proteinuria by 88% at 12 months. Complete remission of proteinuria was more frequently observed in COQ6 disease. CoQ10 supplementation led to significantly better preservation of kidney function (5-year kidney failure-free survival 62% vs. 19%) with an improvement in general condition and neurological manifestations. Side effects of treatment were uncommon and mild. Thus, our findings indicate that all patients diagnosed with primary CoQ10 deficiency should receive early and life-long CoQ10 supplementation to decelerate the progression of kidney disease and prevent further damage to other organs.

Echocardiographic Indices in Pediatric Chronic Kidney Disease.

INTRODUCTION: Cardiovascular disease (CVD) may accompany chronic kidney disease (CKD), resulting in additional complications and increased death rate. This study was performed to evaluate cardiac structure and function and several risk factors in hospitalized CKD children. METHODS: Seventy-four children with CKD were enrolled in this cross-sectional descriptive study. Two-dimensional and M-mode ultrasonography, Doppler flow velocity and Tissue Doppler Imaging (TDI) were used to evaluate cardiac chamber size, left ventricular mass (LVM) and echocardiographic indices of ventricular function. RESULTS: Advanced stages of CKD showed statistically insignificant increased LVM and LVM indexed to height2.7 (LVMI), and mildly reduced diastolic function. Hypertensive patients had an insignificant increase in the incidence of left ventricular hypertrophy (LVH) defined as LVMI greater than 95th percentile for age and sex and LVH2 as LVMI2 more than 95 gr/m2 for girls and more than 115gr/ m2 for boys older than 8 years. Patients with LVH had lower left ventricular ejection fraction (LVEF) and abnormal right ventricular (RV) function based on the tricuspid valve systolic velocity (TV S') survey. LVH2 cases, however, revealed decreased LV systolic function according to ejection fraction (EF) and abnormal mitral valve systolic velocity (MV S'). CONCLUSION: LVH related to hypertension and mild systolic and diastolic dysfunction were more prevalent in advanced CKD cases, however TDI showed no statistically significant difference in the prevalence of MV S' and TV S'. We recommend strict blood pressure control and prevention of renal function deterioration as effective tools for cardiac protection in CKD children.  DOI: 10.52547/ijkd.6643.

Variation of the clinical spectrum and genotype-phenotype associations in Coenzyme Q10 deficiency associated glomerulopathy.

Primary Coenzyme Q10 deficiency is a rare mitochondriopathy with a wide spectrum of organ involvement, including steroid-resistant nephrotic syndrome mainly associated with disease-causing variants in the genes COQ2, COQ6 or COQ8B. We performed a systematic literature review, PodoNet, mitoNET, and CCGKDD registries queries and an online survey, collecting comprehensive clinical and genetic data of 251 patients spanning 173 published (47 updated) and 78 new cases. Kidney disease was first diagnosed at median age 1.0, 1.2 and 9.8 years in individuals with disease-causing variants in COQ2, COQ6 and COQ8B, respectively. Isolated kidney involvement at diagnosis occurred in 34% of COQ2, 10.8% of COQ6 and 70.7% of COQ8B variant individuals. Classic infantile multiorgan involvement comprised 22% of the COQ2 variant cohort while 47% of them developed neurological symptoms at median age 2.7 years. The association of steroid-resistant nephrotic syndrome and sensorineural hearing loss was confirmed as the distinctive phenotype of COQ6 variants, with hearing impairment manifesting at average age three years. None of the patients with COQ8B variants, but 50% of patients with COQ2 and COQ6 variants progressed to kidney failure by age five. At adult age, kidney survival was equally poor (20-25%) across all disorders. A number of sequence variants, including putative local founder mutations, had divergent clinical presentations, in terms of onset age, kidney and non-kidney manifestations and kidney survival. Milder kidney phenotype was present in those with biallelic truncating variants within the COQ8B variant cohort. Thus, significant intra- and inter-familial phenotype variability was observed, suggesting both genetic and non-genetic modifiers of disease severity.

Comparison Between eGFR by Schwartz Formula with Measured GFR by Radionuclide Diethylenetriamine Pentaacetic Acid Scan (Tc99 DTPA scan), in Patients Undergoing Chemotherapy with Nephrotoxic Drugs.

INTRODUCTION: Children with malignancy who are under treatment with nephrotoxic drugs are at risk of renal dysfunction. Due to increased life expectancy, evaluation of drug toxicity is now of higher importance than before. The aim of this study is to compare two methods of GFR measurement. METHODS: An analytical study on children with malignancy undergoing chemotherapy with nephrotoxic drugs (cisplatin, carboplatin, cyclophosphamide, ifosfamind, etoposide) during 2016 and 2017 in Mofid Children Hospital was done. Demographic information, anthropometric measurements, type of malignancy, type of chemotherapy medication and also lab tests including CBC and the biochemistry indices were recorded. The GFR of each patient was calculated using Schwartz formula and DTPA scanning. The rates were compared and the difference was analyzed statistically. RESULTS: According to Schwartz formula, 24% of patients needed dose adjustment, while based on DTPA scanning, this rate was 6%. Comparing these two measures by paired T-test, showed a significant statistical difference (P < .05). Schwartz formula had 25.5% more positive results of predicting the need for dose adjustment. The two measured GFRs for each person were evaluated in terms of compatibility and correlation based on Kappa statistical method, which were incompatible and had significant difference (P < .05). CONCLUSION: Using evaluative methods including Schwartz formula cannot demonstrate renal dysfunctions reliability in patients taking nephrotoxic chemotherapy drugs. Eventually if the GFR measurement method overestimates patients with renal dysfunction, the patients will not be able to make adequate use of the therapeutic effects of chemotherapy with the appropriate dosage.

Urinary System and Renal Involvement in Children With Cystic Fibrosis.

INTRODUCTION: A few data on the prevalence of renal involvement in cystic fibrosis and its spectrum in childhood is available. In the present study, we conducted a prospective study on children who had cystic fibrosis and evaluated their renal involvement. In fact, the aim of the study was to provide data on the clinical consequences of proper identification of kidney disease in a group of children with cystic fibrosis. METHODS: This prospective study was conducted on 55 consecutive patients with previous diagnosis of cystic fibrosis during a threeyear period and at least 3 months to over 5 years or more follow-up. The inclusion criteria was the diagnosis of cystic fibrosis which was made by clinical presentation of cystic fibrosis and laboratory results. Initially, patients' medical records were reviewed and relevant data were collected. A 24-hour urine collection (or a random urine sampling in very young infants) was used to assess crystalluria and renal function was evaluated by blood sampling. RESULTS: Totally, 55 patients with cystic fibrosis were admitted in two hospitals with the mean age of 8.22 ± 5.66 years. GFR totally reduced in 34.5%. The overall prevalence of hypercalciuria was estimated to be 60%, while hyperoxaluria, hypocitraturia, and hyperuricosuria in 41.8%, 24.5%, and 47.3%; respectively. CONCLUSION: Crystalluria is a common consequence of cystic fibrosis in childhood. The prevailing crystalluric finding includes hypercalciuria followed by hyperuricosuria, and hyperoxaluria. During disease GFR may be decreased due to several reasons such as nephrotoxic drugs usage.

Thyroid Dysfunction in Children with Idiopathic Nephrotic Syndrome Attending a Paediatric Hospital in Qazvin, Iran.

OBJECTIVES: Nephrotic syndrome is a glomerular disease characterised by a loss of albumin and high-molecular-weight proteins such as thyroxine-binding globulin and thyroid hormones, potentially resulting in subclinical or even overt hypothyroidism. This study aimed to compare thyroid hormone levels between nephrotic children and healthy controls as well as between nephrotic children in the active phase of the disease and those in remission. METHODS: This case-control study was conducted between March 2016 and 2018 at a paediatric hospital in Qazvin, Iran. A total of 73 nephrotic children comprised the case group-including 49 with active disease and 24 in remission-while the control group included 74 healthy children. Thyroid function was assessed according to levels of thyroid-stimulating hormone (TSH), free triiodothyronine (T3), free thyroxine (T4), total T4, total T3 and anti-thyroid peroxidase. RESULTS: All of the controls had normal total T4 levels. Elevated TSH levels were more frequent in nephrotic children compared to controls (34.2% versus 10.8%; P = 0.001). A significantly lower number of patients with active disease were euthyroid compared to those in remission (51% versus 95.8%; P = 0.001). Moreover, 7 (9.5%) of patients in the active and no patient in remission phase had abnormal total T4 levels (P <0.001), while 14.3% and 0% had highly elevated TSH levels (P = 0.002). CONCLUSION: Due to the prevalence of subclinical and even overt hypothyroidism, thyroid screening tests may be required for nephrotic children. However, further research is needed to confirm these findings.

Vitamin D deficiency and its impact on asthma severity in asthmatic children.

BACKGROUND: Despite obtaining evidences on association between vitamin D and development of lung in fetus, little is known about vitamin D level and its impact on severity of asthma in children. The present study aimed to assess the relationship between the asthma severity and vitamin D deficiency in asthmatic children. METHODS: This case-control study was conducted on 106 individuals including asthmatic (n = 53) and healthy children (n = 53) who referred to Mofid hospital in Tehran in 2013. The level of serum vitamin D in both groups was measured by radioimmunoassay method at the reference lab and was categorized as sufficient (> 30 ng/ml), insufficient (20 to 30 ng/ml), or deficient (< 20 ng/ml). The control status of asthma in patients group was classified as controlled, partially controlled, and uncontrolled. RESULTS: In the groups with and without asthma, the prevalence of vitamin D deficiency was 73.6 and 49.1%, and the prevalence of vitamin D insufficiency was 18.9 and 18.9%, while normal vitamin D level was revealed in 7.5 and 32.1%, respectively with a significant difference (p = 0.005). Using the multivariate logistic regression analysis, the presence of asthma was associated with reduced level of vitamin D (OR = 1.068, 95% CI: 1.027-1.110, P = 0.001). In this context, the risk for asthma in the children with vitamin D deficiency was 6.3 times of those with normal vitamin D level. Although the presence of asthma was strongly associated with reduced level of vitamin D in serum, neither severity of asthma nor control status of asthma were associated with vitamin D deficiency. CONCLUSION: The presence of vitamin D deficiency effectively predict increased risk for childhood asthma; however the severity or control status of this event may not be predicted by confirming vitamin D deficiency.

Serum and Urine Leptin Concentrations in Children Before and After Treatment of Urinary Tract Infection.

INTRODUCTION: Urinary tract infection (UTI) among children is sometimes associated with anorexia and sometimes failure to thrive. Appetite-regulating hormones may be a causative factor. Leptin regulates appetite, food intake, and body weight via hypothalamic melanocortin-4 receptor. Leptin is also a potential cytokine for inflammation. The aim of this study was to evaluate serum and urine leptin before and after treatment of children with UTI. MATERIALS AND METHODS: In this before-after study, serum and urine leptin were measured in 40 patients with UTI at admission and 5 days after treatment. Pyelonephritis was suggested by signs and symptoms and confirmed with positive urine culture and dimercaptosuccinic acid renal scintigraphy. Other measurements included urinalysis, urine culture, urine creatinine level, complete blood count, erythrocyte sedimentation rate, C-reactive protein level and serum levels of urea, creatinine, glucose, cholesterol, and triglyceride. RESULTS: The mean serum leptin level was 6.85 ± 18.90 ng/mL before the treatment and 8.29 ± 18.30 ng/mL after the treatment, the difference of which was not significant (P = .64). There were significant correlations between serum leptin and age, weight, and C-reactive protein. Urine leptin levels were reduced significantly from 0.75 ± 0.82 ng/mL to 0.46 ± 0.27 ng/mL after the treatment (P = .03). A significant correlation was observed between urine leptin level with age and weight. CONCLUSIONS: Serum leptin level did not change significantly after treatment of UTI, but urine leptin significantly decreased. Serum leptin level was higher in patients with anorexia in comparison with children with normal appetite; however, the difference was not significant.

The value of direct radionuclide cystography in the detection of vesicoureteral reflux in children with normal voiding cystourethrography.

BACKGROUND: Vesicoureteral reflux (VUR) is one of the most important risk factors for urinary tract infection (UTI). Diagnosis and treatment of VUR is important to prevent irreversible complications, such as renal scarring and chronic renal failure. This study was conducted to assess the value of direct radionuclide cystography (DRNC) in the detection of VUR in children with UTI and a normal voiding cystourethrography (VCUG). METHODS: DRNC was performed in 35 children with a normal VCUG after an episode of febrile UTI who had hydronephrosis or hydroureter, abnormal acute dimercaptosuccinic acid (DMSA) scan results and/or febrile UTI recurrence. This study was conducted in the nephrology department of Mofid Children's Hospital, Tehran (Iran). RESULTS: The results were statistically analyzed. Among the 70 ureters studied, 33 (49.1 %) were observed to have VUR. Of these, 17 (51.5 %) had mild, 14 (42.4 %) moderate, and 2 (6.1 %) severe reflux. A significant relationship was observed between DRNC results and DMSA renal scan findings (P < 0.05). CONCLUSIONS: Based on our results, we suggest that DRNC may reveal VUR despite a normal VCUG in children with hydronephrosis, abnormal acute DMSA, and/or recurrent febrile UTI.

Tuberous sclerosis presenting with acute kidney failure, pyelonephritis, and polycystic kidney disease.

Tuberous sclerosis complex (TSC) is a multisystemic inherited autosomal dominant disease characterized by the development of hamartomas in the brain and kidneys. In about 2% of patients, polycystic kidney disease is present, which may result in different stages of renal insufficiency. Acute kidney failure has not been reported in infants with TSC. We report a female infant with TSC who was admitted to hospital with pyelonephritis, acute kidney injury, and polycystic kidney disease.

Diagnostic accuracy of renal pelvic dilatation in determining outcome of congenital hydronephrosis.

INTRODUCTIONS: The widespread use of prenatal ultrasonography results in increased recognition of congenital hydronephrosis, a therapeutic and diagnostic challenge. This study was conducted to investigate the natural course of prenatal hydronephrosis and the accuracy of postnatal APD in determining the outcome. MATERIALS AND METHODS: All newborns with prenatal hydronephrosis were followed up by ultrasonography after birth. Voiding cystoureterography, diethylene triaamine pentaacetic acid renal scintigraphy, and dimercaptosuccinic acid renal scintigraphy were done if indicated. The receiver operating characteristic curve was plotted to determine the best cutoff for the anterior-posterior pelvic diameter (APD) to distinguish surgical from spontaneously resolving group. RESULTS: Of 178 neonates, 42 (23%) required surgery. The area under the curve for APD to predict the need for surgery was 0.925 with an APD cutoff of 15 mm. The diagnostic value of APD for determining the need for surgery was determined by sensitivity and specificity of 95.2% and 73.5%, respectively. CONCLUSIONS: Postnatal APD on ultrasonography has a valuable diagnostic accuracy for requiring surgery and provides a useful guide for parental counseling.

Effects of interleukin 2 receptor blockers on patient and graft survival in renal-transplanted children.

BACKGROUND: Monoclonal antibodies block interleukin-2 receptors on alloantigen-reactive T-Lymphocytes and induce selective immunosuppression. It is postulated that induction therapy with these agents in pediatric transplantation may decrease acute rejection and improve graft survival with no significant side effect or increase in the incidence of viral infections. OBJECTIVES: The aim of this study was to examine the effects of interleukin 2 receptor blockers on patient and graft survival in renal-transplanted children. PATIENTS AND METHODS: One hundred and eighty six children aged 7-13 years who received renal transplantation in university-affiliated hospital between 2003 and 2012 were enrolled in the study. All patients received prednisolone, cyclosporine and mycophenolate mofetil or azathioprine as basic immunosuppressive therapy. Patients were divided into two groups according to receiving induction therapy with IL2-receptor blockers. We investigated for acute rejection episodes, Cytomegalovirus (CMV) and BK virus infection and one and three year's survival of the patients and the grafts. RESULTS: From 186 renal-transplanted children included in this study, 36 patients were in treated group (group 1) and 150 patients in control group (group 2). The mean age of the patients was 10.4 ± 2 years and 55.6% were males. In first six months of transplantation, eight patients in group one had one episode of acute rejection and no one had two episodes. Early acute rejection rate was 8.36 (22%). In the control group, 37 patients had one episode and three patients had two episodes of acute rejection (rejection rate 28.6%). Therefore, early acute rejection rates were lower in group one. Late acute rejection rates did not show any difference in group 1 and group 2 (27.7% vs. 27.3% respectively). There was lower prevalence of steroid-resistance rejection in group 1 patients (5.5%) compared with 6.6% in group 2, but it did not reach statistical significance. None of the patients in IL2-R blocker group died at one year follow-up (patient survival 100%). However, in control group, four (2.6%) patients died toward the end of first year (patient survival 97.4%). When patients in group 1 and group 2 were age and sex matched with equal number the difference was significant (P < 0.05). CONCLUSIONS: Induction therapy with IL2-R blockers reduced the rate of early acute rejection, but had no effect on late acute rejections. Patient and graft survival were better in treated group, but did not reach statistical significance. A longer period of follow-up may be required to discern a clear advantage for induction therapy with these agents.

Urinary adrenomedullin level in children with acute pyelonephritis before and after treatment.

INTRODUCTION: Adrenomedullin (AM) is a 52-amino acid peptide that causes vasodilatation by increased synthesis of nitric oxide. Its production by different cells such as cardiac myocytes, smooth muscle, endothelial, and oncogenic cells is stimulated by inflammatory processes. It has been shown that in the presence of inflammation in the urinary system, concentration of AM increases. In this study, we measured urinary AM in children with acute pyelonephritis before and after treatment and compared its level with that in healthy children. MATERIALS AND METHODS: In a case-control study, 31 children with clinical and paraclinical documentation of pyelonephritis (case group) and 30 healthy children without pyelonephritis or other infections (control group) were studied. Urinary AM were measured on spot urine samples by high-performance liquid chromatography, and creatinine was measured by spectrophotometry to report the AM-creatinine ratio. RESULTS: Urinary AM-creatinine ratios were 61.3 +/- 119.4 pg/mg and 4.26 +/- 11.4 pg/mg, respectively, in the case and control groups (P = .01). After treatment of pyelonephritis in the patients of the case group, this ratio decreased to 13.1 +/- 21.9 (P = .048). The coefficient correlation between urinary AM and leukocytes count was 0.252 (P = .17). Urinary AM levels were 1896 +/- 1748 pg/dL and 391 +/- 477 pg/dL in the patients with 4+ versus negative C-reactive protein levels, respectively (P = .008). CONCLUSIONS: Urinary AM increases in the course of pyelonephritis and decreases significantly after treatment.

Protective effect of heparin and aspirin against vascular thrombosis in pediatric kidney transplants.

INTRODUCTION: This study was conducted to evaluate preventive effect of a combination of heparin and aspirin on vascular thrombosis and kidney transplant outcomes of pediatric kidney transplant recipients. MATERIALS AND METHODS: Twenty-four pediatric kidney transplant recipients received heparin, 50 U/kg, every 8 hours for 7 postoperative days, and aspirin, 5 mg/kg, thrice a week from day 3 of transplantation for 3 months. These patients were compared with a matched group of pediatric kidney allograft recipients in terms of development of thrombosis and serum creatinine level at 1 year postoperation. RESULTS: The mean age of patients was 9.4 ± 3.2 years. No vascular thrombosis was developed among the 24 patients with anticoagulant therapy, while in the control group, 5 grafts (7.9%) developed thrombosis (P = .19). Serum creatinine levels at 1 year were lower in the children with anticoagulant therapy as compared with the controls (P = .02). CONCLUSIONS: Our study revealed a reduction in kidney allograft thrombosis incidence in children who received heparin and aspirin after transplantation, which was clinically important although the difference was not statistically significant. Lower serum creatinine levels as compared with a historical cohort group were seen 1 year after transplant surgery. These findings are required to be confirmed by further studies.

Distal renal tubular acidosis and its relationship with hearing loss in children: preliminary report.

INTRODUCTION: In autosomal recessive distal renal tubular acidosis (DRTA), a substantial fraction of the patients have progressive bilateral sensorineural hearing loss. This coexistence is due to the mutations of a gene expressed both in the kidney and in the cochlea. The aim of this study was to assess the correlation between hearing loss and DRTA. MATERIALS AND METHODS: In this study, 51 children diagnosed with renal tubular acidosis were evaluated. Diagnosis of DRTA was based on clinical manifestations and detection of normal anion gap metabolic acidosis, urine pH higher than 5.5, and positive urinary anion gap. Audiometry was performed in children with DRTA and sequencing of the ATP6V1B1 gene was done for those with sensorineural hearing loss. RESULTS: Twenty-seven patients (52.9%) had DRTA, of whom 51.9% were younger than 1 year old, 55.6% were boys, and 44.4% were girls. Eleven patients (40.7%) had bilateral sensorineural hearing loss, consisting of 5 of 15 boys (33.3%) and 6 of 12 girls (50.0%). There was no correlation between hearing loss and gender. Three patients with hearing loss had mutation in the ATP6V1B1 gene (11.1% of patients with DRTA and 27.3% of patients with DRTA and hearing loss). CONCLUSIONS: This study indicated that a significant percentage of the children with DRTA had sensorineural hearing loss and mutation in ATP6V1B1 gene. It is recommended to investigate hearing impairment in all children with DRTA.