Novel SLC30A2 mutations in the pathogenesis of transient neonatal zinc deficiency

Abstract

Importance Transient neonatal zinc deficiency (TNZD) occurs in breastfed infants due to abnormally low breast milk zinc levels. Mutations in the solute carrier family 30 member 2 ( SLC30A2 ) gene, which encodes the zinc transporter ZNT2, cause low zinc concentration in breast milk. Objective This study aimed to provide further insights into TNZD pathophysiology. Methods SLC30A2 sequencing was performed in three unrelated Japanese mothers, whose infants developed TNZD due to low‐zinc milk consumption. The effects of the identified mutations were examined using cell‐based assays and luciferase reporter analysis. Results Novel SLC30A2 mutations were identified in each mother. One harbored a heterozygous missense mutation in the ZNT2 zinc‐binding site, which resulted in defective zinc transport. The other two mothers exhibited multiple heterozygous mutations in the SLC30A2 promoter, the first mutations in the SLC30A2 regulatory region reported to date. Interpretation This report provides new genetic insights into TNZD pathogenesis in breastfed infants.

Analysis of similarities and differences between transient symptomatic zinc deficiency and acrodermatitis enteropathica in children: a case report of a Chinese Yi-ethnic infant

“…Preterm and low birth weight infantsare more susceptible to developing zinc deficiency than full-term infants due to their inadequate zinc stores, compromised ability to absorb zinc from the intestine and increased zinc requirements during catch-up growth [ 21 ]. PN is considered a risk factor of acquired zinc deficiency in numerousreports, associated with a lack of awareness and inadequate management of the importance of trace elements in PN, leading to an iatrogenic TSZD [ 22 , 23 ]. In the case we report, the simultaneous presence of aforementioned three risk factors -preterm, low birth weight, and a history of PN- result in severe zinc deficiency shortly after birth.…”