{'fraction_non_alphanumeric': 0.031071983428275506, 'fraction_numerical': 0.01320559295701709, 'mean_word_length': 5.353618421052632, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Kidney donor with Down syndrome: A unique case of successful kidney transplantation

Dear Editor, Down syndrome is the most common chromosome abnormality among liveborn children. It is characterized by intellectual disability and various congenital malformations that can affect multiple organ systems, including the urinary tract and kidneys [1, 2]. We present the first case of kidney transplantation from a donor with Down syndrome. Institutional Ethics Committee approved the study. At the age of 16, the patient was diagnosed with advanced kidney disease. Thorough workup, including kidney biopsy, showed medullary cystic disease. Due to further progression of kidney failure, peritoneal dialysis was started, and after 3 years, he was switched to hemodialysis. After 7 months on hemodialysis, he received a kidney from a deceased donor. The donor was 24 years old female with Down syndrome with subarachnoidal bleeding. According to the donor report, there were no other concomitant abnormalities except mitral valve prolapse and chronic thyroiditis. Serum creatinine was 140 μmol/L, eGFR 45 mL/min/1.73 m, urine sediment revealed significant bacteriuria with a trace of erythrocytes and protein, and histological analysis of preimplantation biopsy showed moderate acute tubular necrosis while glomeruli, interstitium, and blood vessels were normal. ECHO finding revealed normal morphology of both kidneys. Immunosuppressive therapy included basiliximab induction with tacrolimus, MMF, and steroid maintenance. Primary graft function was established with no complications in the early and later posttransplant period. The incidence of renal and urinary tract anomalies in patients with Down syndrome is relatively low compared with other organ systems, especially cardiovascular. According to the meta-analysis of Mercer et al., renal and urological diseases are more likely to occur in patients with Down syndrome than in the general population, with a reported incidence of 3.5%–21.4% [1]. A variety of urinary tract and renal anomalies have been described. The coincidence of these anomalies and Down syndrome was first reported in 1960. The authors report on 141 Down syndrome autopsy cases with five cases of renal involvement, including renal agenesis and hypoplasia, horseshoe kidney, and urethral valve [1]. In a study by Ariel et al., 124 autopsy cases of Down syndrome were examined, and multiple urinary tract and renal anomalies were recorded. The authors noted renal hypoplasia (21.4%), glomerular microcysts (23.7%), and obstructive uropathy (6.5%). They also reported a higher incidence of simple renal cysts than reported in the healthy population (5.6% vs. 0.1%) [3]. Other urinary tract anomalies have also been reported, such as vesicoureteral reflux, posterior urethral valves, urethral stricture, and nonneurogenic bladder [1]. Various glomerulopathies have been reported through sporadic case reports [2]. However, no extensive studies are addressing the spectrum of glomerular lesions in these patients. Said et al. reported a series of 17 patients with Down syndrome who underwent renal biopsy. A broad spectrum of glomerular diseases was found, with IgA nephropathy and focal segmental glomerulosclerosis being the most common, five and four cases, respectively. There were two cases of membranoproliferative, postinfectious, and pauciimmune crescentic glomerulonephritis each, one membranous glomerulonephritis, and one lupus nephritis [4]. There are no reports on kidney donation from a patient with Down syndrome. We present the first case of successful kidney transplantation from a deceased donor with Down syndrome. Renal and urologic involvement is possible in patients with Down syndrome. In the absence of urinary tract or renal anomalies and kidney failure, these patients should be considered as potential kidney donors.