BackgroundCystinuria is an inherited metabolic disease that is caused by defects in two genes, SLC3A1 and SLC7A9, which result in a renal reabsorptive defect of cystine and other dibasic amino acids, including ornithine, arginine, and lysine. Patients usually present with recurrent renal calculi and may develop renal impairment. Medical management includes high fluid intake and chelating agents. To the best of our knowledge, this is the first study describing cystinuria in Saudi Arabia.MethodsA retrospective chart review for cystinuria patients from the genetic and nephrology divisions between 2010 to 2015. All patients were investigated, diagnosed and treated at King Abdulaziz Medical City in Saudi Arabia.ResultsEight patients were identified from five unrelated families. The age of onset ranged from birth to 14 years. The female to male ratio was 1.7:1. Two new variants in the SLC3A1 and SLC9A7 genes were discovered. All of the detected mutations were missense variants in three different exons, such as c.1711 T > A (p.Cys571Ser) (exon 10), c.1166C > T p.Thr389Met (exon 11) and c.1400 T > A p.Met467Lys (exon 8). Additionally, 37.5% of our patients developed arterial hypertension and 25% had urinary tract infection, but none had renal impairment. No significant clinical differences were detected in this study between type A (SLC3A1 variants) and type B cystinuria (SLC7A9 variant). Two cases were diagnosed based on clinical information, biochemical testing and a positive family history as all of the molecular testing for cystinuria was negative.ConclusionCystinuria has wide genetic heterogeneity with a poor genotype/phenotype correlation. Negative molecular investigations should not rule out the disease if clinical and biochemical investigations support the diagnosis. A larger data registry is essential to better describe the cystinuria genotype/phenotype in Saudi Arabia.

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BackgroundMulticystic dysplastic kidney (MCDK) is a type of kidney dysplasia consisting of many irregular, varioussized cysts divided by dysplastic renal tissue, which negatively impacts kidney function. MCDK is one of the most common renal congenital disorders seen in antenatal ultrasounds. The typical prognosis of MCDK is complete or partial involution that starts antenatally and continues postnatally. The aim of the study was to shed light on the overall outcome of patients with MCDK. MethodsWe retrospectively collected data on MCDK patients from 2016 until 2022 at King Abdulaziz Medical City, Ministry of National Guard Health Affairs in Saudi Arabia, Riyadh. The data included the recording of epidemiological data, radiological and laboratory reports, and the presence of urological or non-urologically associated anomalies. ResultsA total of 57 patients with MCDK were reviewed. Seven of them were excluded due to the diagnosis of bilateral MCDK, which was incompatible with life. Of the remaining 50 patients, the right kidney was affected in 52% of them. Most patients were diagnosed antenatally (98%). The mean duration of follow-up for the study was 48 months. Vesicoureteral reflux (VUR) was detected in 22% of the total sample. Overall, 90% of the patients underwent kidney involution. A small percentage had genitourinary anomalies (20%), while a larger percentage (48%) had extrarenal abnormalities. ConclusionMulticystic dysplastic kidney disease is relatively common in children. The prognosis is affected by the presence of genitourinary and non-genitourinary anomalies. Patients have an overall good prognosis with conservative management. Antenatal screening, diagnosis, and long-term nephrological follow-up are essential for the optimal management of patients.

Extracorporeal membrane oxygenation (ECMO) is considered a recognized lifesaving support for patients with cardiorespiratory failure. Acute kidney injury (AKI) and fluid overload are significant morbidity factors resulting in serious complications. The inline hemofilter system (IHS) and the continuous renal replacement therapy (CRRT) machine are different methods of renal replacement therapy for patients with ECMO. IHS is the alternate, safe dialysis modality of choice because it is user-friendly, inexpensive, and efficiently removes fluid overload and renal diffusive clearance. We report on a 20-day-old male neonate with multiple congenital cardiac defects who needed venoarterial ECMO and had AKI necessitating renal replacement therapy using IHS. The patient had stable electrolyte parameters, good ultrafiltration, and efficient diffusive clearance. He was decannulated from ECMO therapy after 9 days without any related complications. Therefore, neonatal IHS is a safe and efficient alternative approach to AKI.