Publications by authors named "Cecilia Mellado"

Article Synopsis
  • KMT2C and KMT2D are important enzymes that modify genes, with KMT2C haploinsufficiency recently linked to Kleefstra syndrome 2, a neurodevelopmental disorder (NDD) with unknown clinical details.
  • A study involving 98 individuals found that most pathogenic variants in KMT2C span nearly all its exons, making variant interpretation difficult; the study also established a KMT2C DNA methylation signature for better classification of the disorder.
  • Key features of KMT2C-related NDD include developmental delays, intellectual disabilities, and distinct facial characteristics, setting it apart from similar conditions like Kleefstra and Kabuki syndromes, indicating the need for its renaming and
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Article Synopsis
  • More children are surviving now thanks to better healthcare, but deaths from birth defects are becoming a bigger problem, especially in low-income countries.
  • There has been some effort to focus on birth defects at global meetings, but support for this has decreased lately, which is a concern.
  • Birth defects currently cause a significant number of deaths in young children and can lead to lifelong health problems, so it's important for countries to improve healthcare to prevent these issues.
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Takayasu arteritis (TA) is a large-vessel vasculitis that rarely presents in infancy. Casitas B-lineage lymphoma (CBL) syndrome is a rare genetic disorder due to heterozygous CBL gene germline pathogenic variants that is characterized by a predisposition to develop juvenile myelomonocytic leukemia (JMML). Vasculitis, including TA, has been reported in several patients.

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Robinow syndrome is characterized by a triad of craniofacial dysmorphisms, disproportionate-limb short stature, and genital hypoplasia. A significant degree of phenotypic variability seems to correlate with different genes/loci. Disturbances of the noncanonical WNT-pathway have been identified as the main cause of the syndrome.

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Background: In 2000, Chile's Ministry of Health mandated fortification of wheat flour with folic acid at a concentration of 2.2 mg/kg to prevent neural tube defects (NTDs), resulting in a 50% reduction in NTD prevalence. Concerns about possible collateral effects of high folic acid intake led, in 2009, to decrease the folic acid fortification to 1.

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Objective: The Latin American Network of Congenital Malformations: ReLAMC was established in 2017 to provide accurate congenital anomaly surveillance. This study used data from ReLAMC registries to quantify the prevalence of microcephaly from 2010 to 2017 (before, during and after the Zika virus epidemic).

Design: Nine ReLAMC congenital anomaly registries provided case-level data or aggregate data for any live births, still births or terminations of pregnancy with microcephaly.

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Skeletal dysplasias (SD) are disturbances in growth due to defects intrinsic to the bone and/or cartilage, usually affecting multiple bones and having a progressive character. In this article, we review the state of clinical and research SD resources available in Latin America, including three specific countries (Brazil, Argentina, and Chile), that have established multidisciplinary clinics for the care of these patients. From the epidemiological point of view, the SD prevalence of 3.

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Germline pathogenic variants in the gene are a well-established cause of hereditary diffuse gastric cancer (HDGC) syndrome. The aim of this study was to characterize mutations associated with HDGC from Chile, a country with one of the highest incidence and mortality rates in the world for gastric cancer (GC). Here, we prospectively include probands with family history/early onset of diffuse-type of GC.

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Pseudohypoparathyroidism (PHP) is a group of rare genetic disorders that share organ targeted resistance to the action of parathyroid hormone (PTH) as a common feature. Biochemically, they may present with hypocalcemia, hyperphosphatemia and elevated PTH. Some forms present with a specific phenotype: short stature, round facies, short neck, obesity, brachydactyly and subcutaneous calcifications, called Albrigth's Hereditary Osteodystrophy (AHO).

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Introduction: The Genetic Branch of the Chilean Society of Paediatrics, given the draft Law governing the decriminalisation of abortion on three grounds, focusing on the second ground, which considers the "embryo or foetus suffering from a congenital structural anomaly or a genetic disorder incompatible with life outside the womb", met to discuss the scientific evidence according to which congenital anomalies (CA) may be included in this draft law.

Methodology: Experts in clinical genetics focused on 10 CA, reviewed the literature evidence, and met to discuss it.

Results: It was agreed not to use the term "incompatible with life outside the womb", as there are exceptions and longer survivals, and change to "congenital anomaly of poor prognosis (CAPP)".

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Background: With the epidemiological changes, the role of genetic factors as a cause of morbidity and mortality is increasing, changing disease patterns of patients admitted to pediatric hospitals.

Aim: To describe the prevalence of genetic diseases (GD) in patients admitted to a tertiary-care hospital Pediatric Service.

Material And Methods: The clinical records of consecutive admissions to a Pediatric Service of a clinical hospital in 2011 were reviewed.

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Background: Deletions in the SHOX gene are the most frequent genetic cause of Leri-Weill syndrome and Langer mesomelic dysplasia, which are also present in idiopathic short stature.

Aim: To describe the molecular and clinical findings observed in 23 of 45 non-consanguineous Chilean patients with different phenotypes related to SHOX deficiency.

Methods: Multiplex ligation-dependent probe amplification was used to detect the deletions; the SHOX coding region and deletion-flanking areas were sequenced to identify point mutations and single-nucleotide polymorphisms (SNPs).

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Backgrounds And Purpose: To correlate the extent of the leptomeningeal angiomatosis with clinical features in Sturge-Weber syndrome (SWS).

Methods: The study group consisted of 86 consecutive patients aged two months to 56 (mean 7.9 +/- 10.

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The combination of Dandy-Walker malformation, other central nervous system anomalies, and postaxial polydactyly has been reported previously in two pairs of siblings. We propose the name 'Pierquin syndrome' for this combination and we report a new patient with this disorder.

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Background: Neurological disturbances are common problems in children with Down Syndrome (DS).

Aim: To determine the prevalence of neurological disorders affecting children with Down Syndrome.

Patients And Methods: Review of medical records of 253 children aged from 1 day to 23 years affected with DS, attended at a public hospital and a University clinic.

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Familial hyperaldosteronism type I is caused by an unequal crossover of 11β-hydroxylase (CYP11B1) and aldosterone synthase (CYP11B2) genes, giving rise to a chimeric CYP11B1/CYP11B2 gene (CG). We describe a family carrying a CG with high levels of free 18-hydroxycortisol but low prevalence of primary aldosteronism (PA) and an atypical CG inheritance pattern in a family of 4 generations with 16 adults and 13 children, we measured the arterial blood pressure, serum aldosterone, and plasma renin activity and then calculated the serum aldosterone:plasma renin activity ratio and urinary free 18-hydroxycortisol. We identified the CG by long-extension PCR and predicted its inheritance pattern.

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Nowadays, the analysis of genetic markers is a very important and validated tool for the identification of individuals, and for paternity testing. To do so, highly variable regions of the human genome are analyzed, making it possible to obtain the genetic profile of an individual, and to distinguish between different individuals. The methodology used is basically the same all over the world, consisting in the analysis of 13 to 15 markers.

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Schizencephaly is a malformation of cortical development characterized by gray matter-lined clefts in the cerebral cortex and a range of neurological presentations. In some cases, there are features of septo-optic dysplasia concurrently with schizencephaly. The etiologies of both schizencephaly and septo-optic dysplasia are thought to be heterogeneous, but there is evidence that at least some cases have genetic origin.

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Frontonasal dysplasia is etiologically heterogeneous and various subsets are known. Pai syndrome is one subset, which is characterized by mild hypertelorism, midline cleft lip, nasal and facial polyps, pericallosal lipoma, ocular anomalies, and normal neuropsychological development. Here, we report seven South American patients and review earlier reported cases.

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To verify whether the decreasing neural tube defects birth prevalence rates in Chile are due to folic acid fortification or to pre-existing decreasing trends, we performed a population survey using a network of Estudio Colaborativo Latino Americano de Malformaciones Congenitas (ECLAMC, Latin American Collaborative Study of Congenital Malformations) maternity hospitals in Chile, between the years 1982 and 2002. Within each maternity hospital, birth prevalence rates of spina bifida and anencephaly were calculated from two pre-fortification periods (1982-1989 and 1990-2000), and from one fortified period (2001-2002). There was no historical trend for spina bifida birth prevalence rates before folic acid fortification, and there was a 51% (minimum 27%, maximum 66%) decrease in the birth prevalence rates of this anomaly in the fortified period.

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