The chromosomal location and expression of SLC39A4, together with mutational analysis of eight families affected with acrodermatitis enteropathica, suggest that SLC39A4 is centrally involved in the pathogenesis of this condition.
The chromosomal location and expression of SLC39A4, together with mutational analysis of eight families affected with acrodermatitis enteropathica, suggest that SLC39A4 is centrally involved in the pathogenesis of this condition.
The human Zip4 gene (Slc39a4) is mutated in the rare recessive genetic disorder of zinc metabolism acrodermatitis enteropathica, but the physiological functions of Zip4 are not well understood.
The possible functional effect of the Leu372Val substitution, together with two pathological mutations at the same codon (Leu372Pro and Leu372Arg) that cause acrodermatitis enteropathica (a disease phenotype characterized by extreme zinc deficiency), was investigated by transient overexpression of human ZIP4 protein in HeLa cells.
The possible functional effect of the Leu372Val substitution, together with two pathological mutations at the same codon (Leu372Pro and Leu372Arg) that cause acrodermatitis enteropathica (a disease phenotype characterized by extreme zinc deficiency), was investigated by transient overexpression of human ZIP4 protein in HeLa cells.
Therefore, normal and AE fibroblasts were grown in normal medium containing physiological levels of Zn (16 micromol/L) for approximately 24 h. The medium was replaced by normal medium (16 micromol/L Zn), Zn-depleted medium (1.5 micromol/L Zn), or Zn-supplemented medium (200 micromol/L Zn) for another 24 h. Regardless of the Zn concentration of the growth medium, the AE fibroblasts contained significantly less Zn than normal fibroblasts grown in comparable medium.
Therefore, to assess human ZnT4 as a candidate gene/protein in acrodermatitis enteropathica or related disorders, we characterized the intron-exon organization of the human ZNT4 gene, which comprises seven distinct exons spanning approximately 38.7 kb.
These studies strongly suggest that wasting and lethality in acrodermatitis enteropathica patients reflects the loss-of-function of the intestine zinc transporter ZIP4, which leads to abnormal Paneth cell gene expression, disruption of the intestinal stem cell niche, and diminished function of the intestinal mucosa.
To investigate the effects of these mutations on function of the Zip4 transporter, we introduced six AE-associated missense mutations into the orthologous mouse ZIP4 gene for functional expression in cultured cells.
We also report the mutational analysis of human SLC30A4 in ten families with acrodermatitis enteropathica, which enabled us to exclude this gene from any involvement in the disorder of the patients examined.
We and others have recently identified the human gene encoding an intestinal zinc transporter of the ZIP family, SLC39A4, as the mutated gene in acrodermatitis enteropathica (AE).
We and others have recently identified the human gene encoding an intestinal zinc transporter of the ZIP family, SLC39A4, as the mutated gene in acrodermatitis enteropathica (AE).
We describe a novel homozygous mutation, 1191insC, in SLC39A4 in a patient from Sierra Leone and suggest that AE should be considered within the differential diagnosis for acrodermatitis in children from Sierra Leone.
We describe a novel homozygous mutation, 1191insC, in SLC39A4 in a patient from Sierra Leone and suggest that AE should be considered within the differential diagnosis for acrodermatitis in children from Sierra Leone.
We report a case of AE presenting with only periorificial and acral dermatitis in which genetic testing revealed two novel compound heterozygous missense mutations for SLC39A4.