Vitamin D-dependent rickets (VDDR) type 1: case series of two siblings with a CYP27B1 mutation and review of the literature / Raquitismo dependente de vitamina D: tipo 1: série de casos de dois irmãos com mutação CYP27B1 e revisão da literatura

Abstract Two siblings presented with clinical and biochemical features of rickets, initially suspected as hypophosphatemic rickets. There was no improvement initially, hence the siblings were reinvestigated and later diagnosed as having vitamin D-dependent rickets (VDDR) type 1 due to a rare mutation in the CYP27B1 gene encoding the 1α-hydroxylase enzyme. Both siblings improved with calcitriol supplementation. The initial presentation of VDDR is often confusing and algorithmic evaluation helps in diagnosis. We also present a brief review of the literature, including genetics.

Resumo Dois irmãos apresentaram características clínicas e bioquímicas do raquitismo, com suspeita clínica inicial de raquitismo hipofosfatêmico. Não houve melhora no início, portanto os irmãos foram reavaliados e, posteriormente, diagnosticados com raquitismo dependente de vitamina D (VDDR) tipo 1 devido a uma rara mutação no gene CYP27B1, que codifica a enzima 1a-hidroxilase. Ambos os irmãos melhoraram com a suplementação de calcitriol. A apresentação inicial do VDDR geralmente é confusa e a avaliação algorítmica ajuda no diagnóstico. Também apresentamos uma breve revisão da literatura, incluindo genética.

Nuclear Imaging in Pediatric Kidney Diseases

Renal scintigraphy is a useful tool in diagnosis and management of various nephro-urological conditions. Tc-99m dimercaptosuccinicacid renal scintigraphy (Tc-99m-DMSA), Tc-99m mercaptoacetyltriglycine (Tc-99m-MAG3) or Tc-99m diethylenetriaminepentaaceticacid (Tc-99m-DTPA) dynamic renal scintigraphy, and Radionuclide micturating cystography are the common scans used in children withkidney diseases. These studies are minimally invasive, easily available, and offer both anatomic details and functional informationrequired for thorough evaluation. At the same time, it is essential to have appropriate knowledge to interpret these studies and be awareof their limitations and pitfalls. The advent of Positron emission tomography-computed tomography/magnetic resonance imaging (PET-CT/MRI) has broadened the scope of nuclear medicine. This article focuses on the technique, interpretation, indication and recentpractice guidelines of renal scintigraphy in children with kidney diseases.