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1.
Int J Mol Sci ; 22(11)2021 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-34064225

RESUMO

Hereditary hyperferritinemia-cataract syndrome (HHCS) is a rare disease characterized by high serum ferritin levels, congenital bilateral cataracts, and the absence of tissue iron overload. This disorder is produced by mutations in the iron responsive element (IRE) located in the 5' untranslated regions (UTR) of the light ferritin (FTL) gene. A canonical IRE is a mRNA structure that interacts with the iron regulatory proteins (IRP1 and IRP2) to post-transcriptionally regulate the expression of proteins related to iron metabolism. Ferritin L and H are the proteins responsible for iron storage and intracellular distribution. Mutations in the FTL IRE abrogate the interaction of FTL mRNA with the IRPs, and de-repress the expression of FTL protein. Subsequently, there is an overproduction of ferritin that accumulates in serum (hyperferritinemia) and excess ferritin precipitates in the lens, producing cataracts. To illustrate this disease, we report two new families affected with hereditary hyperferritinemia-cataract syndrome with previous known mutations. In the diagnosis of congenital bilateral cataracts, HHCS should be taken into consideration and, therefore, it is important to test serum ferritin levels in patients with cataracts.


Assuntos
Catarata/congênito , Ferritinas/genética , Distúrbios do Metabolismo do Ferro/congênito , Adulto , Catarata/genética , Criança , Feminino , Humanos , Ferro/metabolismo , Distúrbios do Metabolismo do Ferro/genética , Proteínas Reguladoras de Ferro/genética , Mutação/genética
2.
IJTLD Open ; 1(4): 154-159, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38988408

RESUMO

BACKGROUND: Data on the prevalence of non-communicable diseases (NCDs) in TB household contacts (HHCs) are limited, yet important to inform integrated screening and care for NCD within contact investigations. It is also unclear if screening these contacts reveals more people with NCDs than individuals in the same neighbourhood. METHOD: We conducted a pilot cross-sectional study in South Africa and Tanzania, enrolling adult HHCs of TB and individuals in neighbourhood households (controls). We inquired about known NCD and systematically measured blood pressure, and tested for spot blood glucose and haemoglobin A1c. RESULTS: We enrolled 203 adult contacts of 111 persons with TB and 160 controls. Among contacts, respectively 12.2% (95% CI 8.3-17.6) and 39.7% (95% CI 33.1-46.7) had diabetes and hypertension, compared to 14.1% (95% CI 9.2-21.0) and 44.7% (95% CI 36.9-52.7) among controls. More than half of NCDs were newly identified. We did not find a significant difference in the prevalence of at least one NCD between the two groups (OR 0.85, 95% CI 0.50-1.45, adjusted for age and sex). CONCLUSIONS: We found a high prevalence of undiagnosed NCDs among contacts, suggesting a potential benefit of integrating NCD screening and care within contact investigations. Screening in the same community might similarly find undiagnosed NCDs.


CONTEXTE: Les données sur la prévalence des maladies non transmissibles (NCD, pour l'anglais « non-communicable diseases ¼) chez les contacts familiaux (HHC, pour l'anglais « household contacts ¼) de personnes atteintes de TB sont restreintes, mais elles revêtent une grande importance pour le dépistage et la prise en charge intégrée des NCD dans le cadre des enquêtes sur les contacts. De plus, on ignore si le dépistage de ces contacts permet de détecter davantage de personnes atteintes de NCD par rapport aux les individus résidant dans le même quartier. MÉTHODE: Nous avons réalisé une étude pilote transversale en Afrique du Sud et en Tanzanie, au cours de laquelle nous avons recruté des adultes HHC de personnes atteintes de TB et des individus vivant dans les ménages voisins (témoins). Nous les avons interrogés sur les NCD connues et avons systématiquement mesuré la pression artérielle, ainsi que réalisé des tests de de glycémie et d'hémoglobine glyquée. RÉSULTATS: Un total de 203 contacts adultes de 111 personnes atteintes de TB et 160 témoins ont été répertoriés. Parmi ces contacts, respectivement 12,2% (IC à 95% 8,3­17,6) et 39,7% (IC à 95% 33,1­46,7) souffraient de diabète et d'hypertension, contre 14,1% (IC à 95% 9,2­21,0) et 44,7% (IC à 95% 36,9­52,7) chez les témoins. Plus de la moitié des NCD ont été récemment découvertes. Aucune disparité significative n'a été observée dans la prévalence d'au moins une NCD entre les deux groupes (OR 0,85 ; 95% CI 0,50­1,45, ajusté pour l'âge et le sexe). CONCLUSIONS: Nous avons observé une fréquence élevée de NCDs non diagnostiquées parmi les contacts, ce qui indique qu'il pourrait être potentiellement bénéfique d'inclure le dépistage et les soins des NCD dans les enquêtes sur les contacts. Le dépistage au sein de la même communauté pourrait également révéler des NCD non diagnostiquées.

4.
J Mol Biol ; 425(18): 3301-10, 2013 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-23806658

RESUMO

IRP1 [iron regulatory protein (IRP) 1] is a bifunctional protein with mutually exclusive end-states. In one mode of operation, IRP1 binds iron-responsive element (IRE) stem-loops in messenger RNAs encoding proteins of iron metabolism to control their rate of translation. In its other mode, IRP1 serves as cytoplasmic aconitase to correlate iron availability with the energy and oxidative stress status of the cell. IRP1/IRE binding occurs through two separate interfaces, which together contribute about two-dozen hydrogen bonds. Five amino acids make base-specific contacts and are expected to contribute significantly to binding affinity and specificity of this protein:RNA interaction. In this mutagenesis study, each of the five base-specific amino acids was changed to alter binding at each site. Analysis of IRE binding affinity and translational repression activity of the resulting IRP1 mutants showed that four of the five contact points contribute uniquely to the overall binding affinity of the IRP1:IRE interaction, while one site was found to be unimportant. The stronger-than-expected effect on binding affinity of mutations at Lys379 and Ser681, residues that make contact with the conserved nucleotides G16 and C8, respectively, identified them as particularly critical for providing specificity and stability to IRP1:IRE complex formation. We also show that even though the base-specific RNA-binding residues are not part of the aconitase active site, their substitutions can affect the aconitase activity of holo-IRP1, positively or negatively.


Assuntos
Proteína 1 Reguladora do Ferro/metabolismo , Ferro/farmacologia , Nucleotídeos/metabolismo , Elementos de Resposta/genética , Animais , Sítios de Ligação/genética , Domínio Catalítico/genética , Regulação para Baixo/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Proteína 1 Reguladora do Ferro/química , Proteína 1 Reguladora do Ferro/genética , Proteína 1 Reguladora do Ferro/fisiologia , Modelos Moleculares , Mutagênese Sítio-Dirigida , Proteínas Mutantes/química , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Conformação de Ácido Nucleico , Nucleotídeos/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Coelhos , Saccharomyces cerevisiae , Especificidade por Substrato
5.
EJIFCC ; 23(2): 51-4, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27683412

RESUMO

BACKGROUND: In clinical medicine, ferritin is predominantly utilized as a serum marker of total body iron stores. In cases of iron deficiency and overload, serum ferritin serves a critical role in both diagnosis and management. Elevated serum and tissue ferritin are linked to coronary artery disease, malignancy, and poor outcomes following stem cell transplantation. Ferritin is directly implicated in less common but potentially devastating human diseases including sideroblastic anemias, neurodegenerative disorders, and hemophagocytic syndrome. METHOD: We report a case of congenital hyperferritinemia with serum iron within reference range, along with bronchopneumonia, acyanotic congenital heart disease, anemia, hypocalcaemia and dysmorphism in a 2 month old baby. Symptomatic treatment was given. RESULT: The baby was discharged after 7 days. In a stable condition and having gained some weight.He was diagnosed as a case of congenital hyperferritinemia as C reactive protein levels normalized but ferritin levels remained high and A37C mutation within the iron-responsive element of L-ferritin was detected. He was born to consanguineous parents, there was history of cataract in the family and his mother also had high serum ferritin levels. CONCLUSION: This case is an example of the detection of a rare genetic disorder in a child admitted with apparently innocuous symptoms of fever and inflammation. Our case underlines the importance of monitoring ferritin levels, along with other signs of inflammation in order to differentiate congenital hyperferritinemia from inflammatory cause.

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