Typical Features of Amelogenesis Imperfecta in Two Patients with Bartter’s Syndrome

Abstract

Background/Aims: Amelogenesis imperfecta (AI) is due to many inherited defects of enamel formation that affect the quantity and quality of enamel, leading to delay in tooth eruption and cosmetic consequences. AI has been described in association with nephrocalcinosis, which is called the enamel-renal syndrome. The aim of this case report is to describe typical features of AI in 2 patients with Bartter’s syndrome (BS) for the first time. Methods: -Eight patients with confirmed BS were systematically screened for dental abnormalities as part of protocol. Those with suggestive clinical features of AI were submitted to panoramic X-ray and decayed teeth were analyzed by scanning electron microscopy. Results: Typical features of AI were detected in 2 girls with BS. These 2 patients showed nephrocalcinosis, and diagnosis and adequate clinical control were delayed. Genetic analysis detected the mutation responsible for BS in 1 of these patients. In this case, BS was due to a homozygous mutation of exon 5 of the KCNJ1 gene resulting in a substitution of valine for alanine at the codon 214 (A214V). Conclusions: The finding of typical features of AI in BS might constitute preliminary evidence that abnormalities of the biomineralization process found in patients with renal tubular disorders might also affect calcium deposition in dental tissues.

Amelogenesis imperfecta in familial hypomagnesaemia and hypercalciuria with nephrocalcinosis caused byCLDN19gene mutations

“…Recently, ERS was linked to mutations in the FAM20A gene, which encodes a protein that stimulates kinase activity of FAM20C 43–46. Other molecular studies reported AI in patients affected by different diseases with kidney impairment such as Bartter syndrome due to potassium channel KCNJ1 mutation (#241200),47 Raine syndrome due to FAM20C mutations,48 polycystic kidney disease caused by a MSX2 mutation49 and more recently, FHHNC in patients carrying CLDN16 mutations 23. Additional studies without molecular data reported an AI phenotype in inherited kidney diseases such as renal osteodystrophy,50 distal renal tubular acidosis50 and FHHNC 51…”

Dental findings in Brazilian patients with Fanconi syndrome

“…4 Enamel alterations compatible with hipoplasic amelogenesis imperfecta were observed in two unrelated girls with Bartter syndrome by oral and electron microscopy examinations. 4 Bartter syndrome is another renal tubular disorder that normally affects mineral metabolism. 4 Taken together, our previous and present findings suggest that abnormalities of the biomineralization process found in patients with renal tubular disorders might also affect calcium deposition in dental tissues.…”

“…Dental alterations in renal disorders have been described in the literature . Enamel alterations compatible with hipoplasic amelogenesis imperfecta were observed in two unrelated girls with Bartter syndrome by oral and electron microscopy examinations . Bartter syndrome is another renal tubular disorder that normally affects mineral metabolism .…”

“…4 Bartter syndrome is another renal tubular disorder that normally affects mineral metabolism. 4 Taken together, our previous and present findings suggest that abnormalities of the biomineralization process found in patients with renal tubular disorders might also affect calcium deposition in dental tissues. 4 The genetic causes of primary FS remain unknown in most cases.…”

“…1 Alterations in mineral metabolism identified in renal tubular disorders might be associated with dental abnormalities, once dental enamel is the most mineralized tissue in human body. 4 Orofacial manifestations of primary FS were previously reported only by Morisaki in 1989, which described a case of the first offspring of healthy parents without consanguineous marriage with growth deficiency of craniofacial bones and dental alterations. 5 Thus, the aim of this study was to report, for the first time, dental abnormalities in two Brazilian patients with primary form of FS.…”