Prevalence of neonatal idiopathic hypocalcaemia and recurrent infections/immunodeficiency among individuals with suspicious of 22q11.2 deletion syndrome

Abstract

The Syndrome 22q11.2 Deletion Syndrome (22q11.2DS) is the most common chromosomal microdeletion in humans and has wide clinical variability. Its association with idiopathic neonatal hypocalcaemia is related with an imperfection in the development of the third and fourth branchial arcs, leading to hypoplasia or aplasia of the parathyroid and harming the production of the PTH. Immunodeficiency in 22q11.2 DS occurs due to aplasia or hypoplasia of the thymus with problems in the process of production of lymphocytes T. The severity of the immune deficiency varies, as well as its frequency. Despite of these two important manifestations of this condition, the clinical heterogeneity of this condition may results on delay of the diagnosis, compromising the global management and the genetic counseling. In 2013, clinical criteria for the suspicion of 22q11.2 DS was published by this group of research, which had based the construction of specific module for diagnostic support in the application CranFlow (CranFlow- BDDEL22q11.2 - Brazilian database on 22q11.2 deletion syndrome). It registers cases suspicious and allows the addition of the clinical signals during the follow-up. The aim of this study is to contribute for the diagnosis of the 22q11.2 DS by the determination of the prevalence of neonatal hypocalcaemia and recurrent infections/immunodeficiency in cases with suspicion of 22q11.2DS. It will be used the data from CranFlow- BDDEL22q11.2, which now has around 250 cases already registered. The analysis of the data will be descriptive. Comparison between negatives and positives cases for de 22q11.2 DS will be made using the program Epi Info" Version 3.5.1. This approach will bring useful information to improve the identification of pediatric patients with 22q11.2. (AU)