A novel mutation in the SLC40A1 gene associated with reduced iron export in vitro.

Ferroportin disease is an inherited disorder of iron metabolism and is caused by mutations in the ferroportin gene (SLC40A1). We present a patient with hyperferritinemia, iron overload in the liver with reticuloendothelial distribution and also in the spleen, and under treatment with erythropheresis. A molecular study of the genes involved in iron metabolism (HFE, HJV, HAMP, TFR2, SLC40A1) was undertaken. In vitro functional studies of the novel mutation found in the SLC40A1 gene was performed. The patient was heterozygous for a novel mutation, c.386T>C (p.L129P) in the SLC40A1 gene; some of his relatives were also heterozygous for this mutation. In vitro functional studies of the L129P mutation on ferroportin showed it impairs its capacity to export iron from cells but does not alter its sensitivity to hepcidin. These findings and the iron overload phenotype of the patient suggest that the novel mutation c.386T>C (p.L129P) in the SLC40A1 gene has incomplete penetrance and causes the classical form of ferroportin disease.

Mutations in the HFE, TFR2, and SLC40A1 genes in patients with hemochromatosis.

Hereditary hemochromatosis causes iron overload and is associated with a variety of genetic and phenotypic conditions. Early diagnosis is important so that effective treatment can be administered and the risk of tissue damage avoided. Most patients are homozygous for the c.845G>A (p.C282Y) mutation in the HFE gene; however, rare forms of genetic iron overload must be diagnosed using a specific genetic analysis. We studied the genotype of 5 patients who had hyperferritinemia and an iron overload phenotype, but not classic mutations in the HFE gene. Two patients were undergoing phlebotomy and had no iron overload, 1 with metabolic syndrome and no phlebotomy had mild iron overload, and 2 patients had severe iron overload despite phlebotomy. The patients' first-degree relatives also underwent the analysis. We found 5 not previously published mutations: c.-408_-406delCAA in HFE, c.1118G>A (p.G373D), c.1473G>A (p.E491E) and c.2085G>C (p.S695S) in TFR2; and c.-428_-427GG>TT in SLC40A1. Moreover, we found 3 previously published mutations: c.221C>T (p.R71X) in HFE; c.1127C>A (p.A376D) in TFR2; and c.539T>C (p.I180T) in SLC40A1. Four patients were double heterozygous or compound heterozygous for the mutations mentioned above, and the patient with metabolic syndrome was heterozygous for a mutation in the TFR2 gene. Our findings show that hereditary hemochromatosis is clinically and genetically heterogeneous and that acquired factors may modify or determine the phenotype.

Mutaciones en los genes HFE y TFR2 en un paciente español con hemocromatosis / Mutations in HFE and TFR2 genes in a Spanish patient with hemochromatosis

La enfermedad por sobrecarga de hierro está originada por diversas anomalías genéticas. El estudio genético de esta enfermedad confirma su carácter hereditario y nos permite ofrecer consejo genético a los familiares en primer grado. Hemos realizado resonancia magnética y biopsia de hígado en un paciente asintomático con más de 1.000 mg/l de ferritina en suero, y hemos analizado los genes implicados en el metabolismo del hierro. El fenotipo de sobrecarga de hierro se confirmó por la presencia de un patrón de depósito de hierro en el hígado con predominio periportal que sugiere la existencia de una enfermedad genética. En el caso que presentamos, el estudio genético reveló que el paciente es doble heterocigoto para las mutaciones c.187C>G (p.H63D) y c.840C>G (p.F280L) en los genes HFE y receptor 2 de transferrina (TFR2), respectivamente(AU)

Iron overload disease has a wide variety of genotypes. The genetic study of this disease confirms its hereditary nature and enables us to provide genetic counseling for first-degree relatives. We performed magnetic resonance imaging and liver biopsy in an asymptomatic patient with more than 1,000 mg/L of serum ferritin and studied the genes involved in this condition. The phenotype of iron overload is confirmed by a predominantly periportal pattern of iron deposits in the liver suggestive of genetic disease. In the case we present the molecular study revealed a double heterozygosity for the mutations c.187C>G (p.H63D) and c.840C>G (p.F280L) in the HFE and transferrin receptor 2 (TFR2) genes, respectively(AU)

Hiperferritinemia, ferropenia y síndrome metabólico en un paciente con una nueva mutación en el gen TFR2 y otra en el gen FTL. Estudio familiar / Hyperferritinemia, ferropenia and metabolic syndrome in a patient with a new mutation of gene TFR2 and another in gene FTL. A family study

Fundamento y objetivo: La hiperferritinemia es un hallazgo común en la práctica clínica diaria que puede ser congénita o adquirida y no siempre se asocia con sobrecarga férrica. La hiperferritinemia genética puede acompañarse de sobrecarga, como en la hemocromatosis hereditaria, o cursar con cataratas sin sobrecarga, en ese caso es el síndrome hereditario de hiperferritinemia y cataratas. Por otra parte, el síndrome metabólico puede cursar con hiperferritinemia y sobrecarga leve-moderada pero sin aumento de saturación de transferrina. Presentamos una familia con hiperferritinemia.Pacientes y método: Estudio de una familia con hiperferritinemia dual, congénita y adquirida, con análisis de los genes implicados en el metabolismo del hierro. Resultados:Los pacientes con síndrome hereditario de hiperferritinemia y cataratas tienen la mutación c.-167C>T en heterocigosis en el gen FTL. El paciente con síndrome metabólico presenta, además, una nueva mutación en heterocigosis en el gen TFR2 (c.1259G>A, p.Arg420His). Conclusiones: La hiperferritinemia, habitualmente casual, supone para el clínico un reto diagnóstico por sus diversidades fenotípicas y genotípicas, siendo necesario aunar esfuerzos en investigación básica y clínica para la asistencia de los pacientes (AU)

Background and objetives: Hyperferritinemia is a common finding in clinical practice. This condition can be congenital or acquired, although it is not always associated with iron overload. Genetic hyperferritinemia is associated with iron overload, hereditary hemochromatosis, or cataracts that progress without iron overload (hereditary hyperferritinemia-cataract syndrome). Metabolic syndrome is associated with hyperferritinemia and mild iron overload, with no increase in transferrin saturation. We report a family with hyperferritinemia. Patients and methods: We present the study of a family with dual hyperferritinemia (congenital and acquired) and an analysis of the genes involved in iron metabolism. Results: Patients with hereditary hyperferritinemia-cataract syndrome have the mutation c.-167C>T in the FTL gene; patients with metabolic syndrome present a new mutation in the TFR2 gene (c.1259G>A, p.Arg420His).Conclusions: The phenotypic and genotypic diversity of hyperferritinemia makes it a diagnostic challenge for clinicians. Basic research and clinical research should be combined to ensure better patient care (AU)

[Hyperferritinemia, ferropenia and metabolic syndrome in a patient with a new mutation of gene TFR2 and another in gene FTL. A family study]. / Hiperferritinemia, ferropenia y síndrome metabólico en un paciente con una nueva mutación en el gen TFR2 y otra en el gen FTL. Estudio familiar.

BACKGROUND AND OBJECTIVES: Hyperferritinemia is a common finding in clinical practice. This condition can be congenital or acquired, although it is not always associated with iron overload. Genetic hyperferritinemia is associated with iron overload, hereditary hemochromatosis, or cataracts that progress without iron overload (hereditary hyperferritinemia-cataract syndrome). Metabolic syndrome is associated with hyperferritinemia and mild iron overload, with no increase in transferrin saturation. We report a family with hyperferritinemia. PATIENTS AND METHODS: We present the study of a family with dual hyperferritinemia (congenital and acquired) and an analysis of the genes involved in iron metabolism. RESULTS: Patients with hereditary hyperferritinemia-cataract syndrome have the mutation c.-167C>T in the FTL gene; patients with metabolic syndrome present a new mutation in the TFR2 gene (c.1259G>A, p.Arg420His). CONCLUSIONS: The phenotypic and genotypic diversity of hyperferritinemia makes it a diagnostic challenge for clinicians. Basic research and clinical research should be combined to ensure better patient care.

Two novel mutations in the SLC40A1 and HFE genes implicated in iron overload in a Spanish man.

The most common form of hemochromatosis is caused by mutations in the HFE gene. Rare forms of the disease are caused by mutations in other genes. We present a patient with hyperferritinemia and iron overload, and facial flushing. Magnetic resonance imaging was performed to measure hepatic iron overload, and a molecular study of the genes involved in iron metabolism was undertaken. The iron overload was similar to that observed in HFE hemochromatosis, and the patient was double heterozygous for two novel mutations, c.-20G>A and c.718A>G (p.K240E), in the HFE and ferroportin (FPN1 or SLC40A1) genes, respectively. Hyperferritinemia and facial flushing improved after phlebotomy. Two of the patient's children were also studied, and the daughter was heterozygous for the mutation in the SLC40A1 gene, although she did not have hyperferritinemia. The patient presented a mild iron overload phenotype probably because of the two novel mutations in the HFE and SLC40A1 genes.