SLC39A4 mutation in zinc deficiency patients.

ABSTRACT

OBJECTIVE: To analyze the clinical presentation and SLC39A4 mutations in zinc deficiency patients. MATERIAL AND METHOD: The authors conducted a cross-sectional study on all cases of zinc deficiency treated at Queen Sirikit National Institute of Child Health between January 2004 and December 2012. Demographic data, clinical manifestations, laboratory results, treatment and outcome were analyzed. Genetic, SLC39A4 for acrodermatitis enteropathic (AE), mutation analysis was performed in all cases. RESULTS: There were 15 cases, 10 males and 5 females. The age of onset was between 2 and 10 months (median 3 months). Duration of the disease ranged between 3 days and 17 months (median 2 months). Acral and periorificial dermatitis, diarrhea and alopecia were present in 15 cases (100%), 12 cases (80%) and 8 cases (53%) respectively. The characteristic triad of acral and periorificial dermatitis, diarrhea and alopecia was observed in only 6 patients (40%). Serum zinc level ranged between 10 and 111 mcg/dl (mean 49.69 ± 33.87 mcg/100 ml). Low serum zinc level was observed in 10 cases (67%). All of the patients were treated with zinc sulfate 5 mg/kg/day. All cutaneous lesions and diarrhea had resolved within 7 days of starting therapy. A genetic study of SLC39A4 gene in our 15 patients revealed that 3 patients had homozygous c.1878_1879ins21 (p.G627_T633dup) in exonl2. These three patients have to receive lifelong zinc supplementation to prevent recurrence of the disease. The other twelve patients, who did not carry the gene mutation, did not have symptoms after discontinuance of oral zinc therapy. This is the first report of genetically confirmed acrodermatitis enteropathic in Thailand. CONCLUSION: Acrodermatitis enteropathica is a rare disease, which needs lifelong zinc supplementation. A genetic study of SLC39A4 gene will confirm the diagnosis. Most of patients presenting with characteristic triad of acral and periorificial dermatitis, diarrhea and alopecia in Thailand were acquired zinc deficiency. Early recognition and treatment of the disease will decrease morbidity and mortality.