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Enamel renal syndrome (ERS) is a rare autosomal recessive disorder not fully characterized. Here we investigated ERS characteristics in 11 patients from 5 Brazilian families through clinical examination, imaging, renal ultrasonography, laboratory tests and DNA sequencing. The patients' age ranged from 6 to 25 years-old, and the presence of hypoplastic amelogenesis imperfecta, microdontia, intra-pulpal calcification, impacted posterior teeth with hyperplastic pericoronal follicles, gingival fibromatosis, ectopic calcifications on gingival and pericoronal tissues, and nephrocalcinosis were common findings to all patients. Only 4 patients showed abnormal laboratory tests (vitamin D, parathyroid hormone, phosphate, calcium). Intellectual disability and renal cysts were present in 2 patients each. Biallelic loss of function mutation in FAM20A gene, characterized by one base pair deletion in exon 11, resulting in a frameshift replacing a glutamine at codon 483 for a lysine and terminating at position 24 [NG_029809.1: c.1447delG; p.(Glu483Lysfs*24)], was detected in all patients, strongly suggesting a founder effect. Our results reinforce the distinct orofacial features of ERS, which are the clue for kidney examination and genetic testing. Early diagnosis is essential to minimize the deleterious effects related to ERS. Here we report the largest series of patients with ERS in a same population, and describe, for the first time, a founder mutation for FAM20A., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

Enamel-renal syndrome (OMIM #204690) is an uncommon disorder characterized by amelogenesis imperfecta and nephrocalcinosis and is caused by mutations in FAM20 A. We report 2 patients with enamel-renal syndrome who exhibited the typical features of this syndrome and a homozygous nonsense mutation in the FAM20 A gene (c.406 C>T), genetically confirming the diagnosis. They also exhibited 2 undescribed clinical features, hypertrichosis and hearing loss. Alterations in genes frequently associated with nonsyndromic hearing loss in the Brazilian population, including connexin 26 (GJB2), connexin 30 (GJB6) and mitochondrial 12 S rRNA (m.A1555 G mutation), were not found. These results suggest a putative function of FAM20 A in the development of the inner ear and in the formation of hair. The presence of nephrocalcinosis is a risk factor for renal impairment, and it is important to perform regular renal monitoring in order to avoid renal failure., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Neomycin is coupled on xanthan--a polysaccharide of microbial biosynthesis produced by Xanthomona campestris--through ionic complexation. The kinetics of neomycin release, in vitro, at pH = 8.2 is studied. A release of neomycin, following a zero order kinetics, is observed, regardless of the eluent flow-rate. The neomycin-xanthan complex, protected by a cellulosic membrane, behaves like a monolithic-type device. Diffusion coefficients--increasing with increasing the eluent flow-rate--are also calculated.