A research group led by an associate professor at the Graduate School of Life Sciences, Kyoto University, has confirmed multiple mutations that have not been reported in Japan among the genetic mutations that cause low-zinc breast milk that causes growth disorders in infants. Announced that it was done.It suggests that infant zinc deficiency due to zinc deficiency in breast milk is more common than previously predicted.
Zinc is essential for vital activities, albeit in trace amounts, and infants in particular need more zinc to grow than adults.Zinc deficiency in infants causes symptoms such as dermatitis and failure to thrive, which is a serious problem especially for preterm and low weight infants.
Immediately after breastfeeding, breast milk contains zinc that meets the baby's needs, but a lack of this zinc causes the baby to have transient infantile zinc deficiency (TNZD) and must be treated with replacement.Previous studies have shown that mutations in the zinc transporter ZnT2 gene, which secretes zinc into breast milk in the mammary gland, reduce the amount of zinc, but due to the small number of case reports, the incidence of mutations, etc. Was unknown.
In this study, we analyzed genomic DNA in the blood of mothers who developed TNZD.As a result, we found different and unreported mutations on the ZnT2 gene in all mothers.Further culture and analysis revealed that all of the gene mutations found deprived ZnT2 of its zinc-transporting function and caused low-zinc breast milk.From the results of the research, it can be inferred that the number and types of gene mutations that cause TNZD are higher than previously expected.
As breastfeeding is promoted worldwide, the number of cases of TNZD is expected to increase further.The research group said, "Infant zinc deficiency due to low zinc breast milk may occur more than expected in Japan," and cautions are given in advancing breastfeeding, and information on mutations in genes that cause TNZD is accumulated. We would like to proceed with the analysis and use it to prevent zinc deficiency in infants.The results of this research were published in "Pediatric Research".