<?xml version="1.0" encoding="ISO-8859-1"?><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<front>
<journal-meta>
<journal-id>0035-0052</journal-id>
<journal-title><![CDATA[Revista mexicana de pediatría]]></journal-title>
<abbrev-journal-title><![CDATA[Rev. mex. pediatr.]]></abbrev-journal-title>
<issn>0035-0052</issn>
<publisher>
<publisher-name><![CDATA[Sociedad Mexicana de Pediatría A.C.]]></publisher-name>
</publisher>
</journal-meta>
<article-meta>
<article-id>S0035-00522025000400156</article-id>
<article-id pub-id-type="doi">10.35366/121827</article-id>
<title-group>
<article-title xml:lang="es"><![CDATA[Espectro clínico y molecular del síndrome de Imerslund-Gräsbeck]]></article-title>
<article-title xml:lang="en"><![CDATA[Clinical and molecular spectrum of Imerslund-Gräsbeck syndrome]]></article-title>
</title-group>
<contrib-group>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Bindi]]></surname>
<given-names><![CDATA[Verónica]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
<xref ref-type="aff" rid="Aaf"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Crespo]]></surname>
<given-names><![CDATA[Carolina]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Eiroa]]></surname>
<given-names><![CDATA[Hernán]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Gravina]]></surname>
<given-names><![CDATA[Luis Pablo]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
<contrib contrib-type="author">
<name>
<surname><![CDATA[Rossetti]]></surname>
<given-names><![CDATA[Estefanía]]></given-names>
</name>
<xref ref-type="aff" rid="Aff"/>
</contrib>
</contrib-group>
<aff id="Af1">
<institution><![CDATA[,Hospital de Pediatría Juan P. Garrahan Departamento de Errores Congénitos del Metabolismo ]]></institution>
<addr-line><![CDATA[Buenos Aires ]]></addr-line>
<country>Argentina</country>
</aff>
<aff id="Af2">
<institution><![CDATA[,Hospital de Pediatría Juan P. Garrahan Laboratorio de Biología Molecular Departamento de Genética]]></institution>
<addr-line><![CDATA[Buenos Aires ]]></addr-line>
<country>Argentina</country>
</aff>
<aff id="Af3">
<institution><![CDATA[,Hospital de Pediatría Juan P. Garrahan Departamento de Hematología ]]></institution>
<addr-line><![CDATA[Buenos Aires ]]></addr-line>
<country>Argentina</country>
</aff>
<pub-date pub-type="pub">
<day>00</day>
<month>08</month>
<year>2025</year>
</pub-date>
<pub-date pub-type="epub">
<day>00</day>
<month>08</month>
<year>2025</year>
</pub-date>
<volume>92</volume>
<numero>4</numero>
<fpage>156</fpage>
<lpage>161</lpage>
<copyright-statement/>
<copyright-year/>
<self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_arttext&amp;pid=S0035-00522025000400156&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_abstract&amp;pid=S0035-00522025000400156&amp;lng=en&amp;nrm=iso"></self-uri><self-uri xlink:href="http://www.scielo.org.mx/scielo.php?script=sci_pdf&amp;pid=S0035-00522025000400156&amp;lng=en&amp;nrm=iso"></self-uri><abstract abstract-type="short" xml:lang="es"><p><![CDATA[Resumen:  Introducción:  el síndrome de Imerslund-Gräsbeck (IGS) es un trastorno autosómico recesivo causado por variantes patogénicas en los genes CUBN o AMN, que provocan malabsorción de vitamina B12 (cobalamina). Estos pacientes tienen anemia, síntomas gastrointestinales y retraso del crecimiento.  Descripción de los casos:  presentamos cuatro pacientes argentinos, cuyo cuadro clínico se caracterizó por fatiga, palidez, retraso en el neurodesarrollo, diarrea y vómito. Tres tenían anemia megaloblástica y uno anemia macrocítica. Todos con deficiencia de vitamina B12 (niveles séricos &lt; 125 pg/mL), además de proteinuria persistente. La mediana de edad para el inicio de manifestaciones fue a los 21 meses, y de nueve años cuando se estableció el diagnóstico. Por estudio genético, se identificó una nueva variante en CUBN (c.2450G&gt;A; p.Cys817Tyr) en tres pacientes, mientras que el cuarto paciente tenía una deleción intrónica homocigota en AMN (c.1006+34_1007-31del). El tratamiento fue con cobalamina parenteral u oral, con lo que hubo mejoría progresiva.  Conclusiones:  en pacientes con anemia y deficiencia de vitamina B12, se debe considerar al IGS como parte del diagnóstico diferencial. La identificación concomitante de proteinuria puede ayudar a su identificación.]]></p></abstract>
<abstract abstract-type="short" xml:lang="en"><p><![CDATA[Abstract:  Introduction:  Imerslund-Gräsbeck syndrome (IGS) is an autosomal recessive disorder caused by pathogenic variants in the CUBN or AMN genes, leading to malabsorption of vitamin B12 (cobalamin). Patients with IGS have anemia, gastrointestinal symptoms, and growth retardation.  Description of cases:  we present four Argentinian patients with IGS, whose clinical presentation was characterized by fatigue, pallor, neurodevelopmental delay, diarrhea, and vomiting. Three had megaloblastic anemia and one had macrocytic anemia. All had vitamin B12 deficiency (serum levels &lt; 125 pg/mL), as well as persistent proteinuria. The median age of onset was 21 months, and the median age at diagnosis was nine years. A novel homozygous variant in CUBN (c.2450G&gt;A; p.Cys817Tyr) was identified in three patients, while the fourth patient carried a homozygous intronic deletion in AMN (c.1006+34_1007-31del). The treatment was with parenteral or oral cobalamin, with progressive improvement.  Conclusions:  in patients with anemia and vitamin B12 deficiency, IGS should be considered as part of the differential diagnosis. The concomitant identification of proteinuria may aid in its detection.]]></p></abstract>
<kwd-group>
<kwd lng="es"><![CDATA[deficiencia de cobalamina]]></kwd>
<kwd lng="es"><![CDATA[vitamina B12]]></kwd>
<kwd lng="es"><![CDATA[síndrome de Imerslund-Gräsbeck]]></kwd>
<kwd lng="es"><![CDATA[anemia megaloblástica]]></kwd>
<kwd lng="es"><![CDATA[niños]]></kwd>
<kwd lng="en"><![CDATA[cobalamin deficiency]]></kwd>
<kwd lng="en"><![CDATA[vitamin B12]]></kwd>
<kwd lng="en"><![CDATA[Imerslund-Gräsbeck syndrome]]></kwd>
<kwd lng="en"><![CDATA[megaloblastic anemia]]></kwd>
<kwd lng="en"><![CDATA[children]]></kwd>
</kwd-group>
</article-meta>
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