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BACKGROUND: Dense deposit disease (DDD), a subtype of complement factor 3 glomerulopathy (C3G), is a rare entity associated with dysregulation of the alternative complement pathway. It usually affects children, with a 50% likelihood of progression to end-stage renal disease within ten years of diagnosis. Description of the case: We report the case of an adolescent male with acute nephritic syndrome and nephrotic range proteinuria, initially diagnosed as acute post-streptococcal glomerulonephritis (APSGN). Despite his spontaneous improvement, renal biopsy, performed due to a persistently low C3 level for over 18 weeks, confirmed the diagnosis of DDD. Complement and genetic studies showed high levels of C3-nephritic factor and risk polymorphisms for developing the disease. He was treated with prednisolone and mycophenolate mofetil (MMF). At the last follow-up, 15 months from onset, the serum creatinine level and 24h-hour total protein excretion were normal. CONCLUSION: C3G (including the DDD subtype) should be suspected in apparent APSGN with atypical clinical features at presentation/follow-up, even in the case of spontaneous improvement. Timely and accurate diagnosis, based on histopathological, complement, and genetic studies, is important to initiate the appropriate treatment aimed at preventing or slowing the disease progression. HIPPOKRATIA 2020, 24(4): 191-193.

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BACKGROUND: Down syndrome (DS) is the most common aneuploidy in live-born individuals and it is well recognized with various phenotypic expressions. Although an extra chromosome 21 is the genetic cause for DS, specific phenotypic features may result from the duplication of smaller regions of the chromosome and more studies need to define genotypic and phenotypic correlations. CASE REPORT: We report on a 26 year old male with partial trisomy 21 presenting mild clinical symptoms relative to DS including borderline intellectual disability. In particular, the face and the presence of hypotonia and keratoconus were suggestive for the DS although the condition remained unnoticed until his adult age array comparative genomic hybridization (aCGH) revealed a 10.1 Mb duplication in 21q22.13q22.3 and a small deletion of 2.2 Mb on chromosomal band 7q36 arising from a paternal translocation t(7;21). The 21q duplication encompasses the gene DYRK1. CONCLUSION: Our data support the evidence of specific regions on distal 21q whose duplication results in phenotypes recalling the typical DS face. Although the duplication region contains DYRK1, which has previously been implicated in the causation of DS, our patient has a borderline IQ confirming that their duplication is not sufficient to cause the full DS phenotype.

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Tetrasomy 9p is a rare chromosomal syndrome and about 30% of known cases exhibit mosaicism. Approximately 50 of the reported cases with tetrasomy 9p mosaicism show a characteristic facial appearance, growth failure, and developmental delay. However, 3 patients with mosaicism for isochromosome 9p and a normal phenotype have also been reported. We report 2 additional cases of clinically normal young females with tetrasomy 9p mosaicism, one of whom also exhibited X chromosome aneuploidy mosaicism leading to an overall of 6 different cell lines. STR analysis performed on this complex mosaic case indicated that the extra isochromosome was of maternal origin while the X chromosome aneuploidy was of paternal origin, indicating a postzygotic event.

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Children born small (SGA) or large (LGA) for gestational age are prone to develop insulin resistance (IR) during childhood. Visfatin, a hormone with insulin-mimetic actions, has been associated with IR. This study was designed to examine whether serum level of visfatin is correlated with metabolic indices of IR, in prepuberty in association with the intrauterine growth pattern. The following parameters were evaluated at a mean age of 6.5±1.2 years in 155 prepubertal children born appropriate for the gestational age (AGA) (n=63), or SGA (n=42), or LGA (n=50): serum levels of visfatin, adiponectin, leptin, fasting glucose (G(F)) and insulin (I(F)), the homeostasis model assessment IR index (HOMA-IR), plasma lipids, anthropometric indices at birth and the time of evaluation, and obesity indices [waist circumference (WC), body mass index (BMI) and skinfold thickness]. The mean serum level of visfatin was lower in the SGA than in the AGA and the LGA children (9±5.2 vs. 11.8±5.1 and 12.7±5.6 ng/ml, respectively, p<0.01). Girls had lower visfatin levels than boys (10.4±4.3 ng/ml vs. 12.5±6.7 ng/ml, p<0.05). Visfatin was not correlated with IR indices. In multiple regression analysis visfatin level was positively correlated with birth weight z-score (t=2.56, beta=0.24, p<0.01) and crown to heel z-score (t=2.46, beta=0.22, p=0.014), independent of age, gender, maternal weight before pregnancy, maternal weight gain during pregnancy, BMI z-score, WC z-score, serum leptin and adiponectin, and HOMA-IR. In conclusion serum visfatin level was lower in prepubertal SGA children but not correlated with IR indices. Low birth weight was an independent predictor of visfatin level.

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The short-term effects of corticosteroids (CS) administered intravenously (IV) on biochemical parameters of bone metabolism were followed in infants and children. Forty-nine patients from 2 months to 10 years of age, admitted to Pediatrics Department for bronchiolitis, viral-associated wheezing and croup, were treated with IV hydrocortisone or methylprednisolone (10 or 2 mg/Kg/day, respectively) for 3 days. Blood and fasting urine were collected on admission (day 1), 2 days later (day 3) and 12 days after the end of therapy (day 15). Fifty-one children of similar age and gender without respiratory problems or bone diseases were used as controls. On day 3, suppression of the bone formation markers osteocalcin (OC) (P < 0.001) and total alkaline phosphatase (ALP) (P < 0.05) was observed, but not of the bone resorption markers of hydroxyproline, pyridinoline and calcium excretion (UHyp/UCr, UPYD/UCr and UDPD/UCr, UCa/UCr). Significant decreases were indicated in serum phosphate (Pi) and the maximum renal tubular Pi reabsorption (TmP/GFR) compared to basal (P < 0.001). No significant changes were noticed in the circulating levels of calcium (Ca), parathyroid hormone (iPTH), 25OHD, 24,25(OH)2D, 1,25(OH)2D, the insulin-like growth factor-I (IGF-I) and its binding protein-3 (IGFBP-3). Two weeks after therapy, the increase of OC to higher than basal (P < 0.01) indicated a probable activation of the osteoblasts. Serum Pi and the TmP/GFR index values that had significantly decreased by day 3 returned to pretreatment levels by day 15. When assessing the effects of the CS in relation to age, no changes were detected in the levels of OC and total ALP in the <12-month-old children, but a fall of OC was observed in the >1-year-old group (P < 0.001). In contrast to the OC, the effects on serum and renal tubular reabsorption of phosphate were similar for both groups. In conclusion, short-term IV administered CS led to significant but reversible inhibition of bone formation markers, especially detectable in the >1-year-old children, without affecting the bone resorption ones. The adverse effects on phosphate metabolism were also significant, but temporal and irrespective of age.

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