Transplacental transfer of cobalt: Evidence from a study of mothers and their neonates in the African Copperbelt.

BACKGROUND: Transfer of the trace metal cobalt (Co) from mother to foetus has not been documented in populations with high environmental exposure to Co, as is the case in the African Copperbelt mining region. We analysed data obtained from 246 mother-infant pairs included (at delivery) in a previously published case-control study on birth defects, done in Lubumbashi (Democratic Republic of Congo) between March 1, 2013, and Feb 28, 2015. METHODS: Co was measured by Inductively Coupled Plasma Mass Spectrometry in maternal blood, maternal urine, umbilical cord blood and placental tissue, as available. RESULTS: The Co concentrations [geometric mean (GM) with interquartile range (IQR)] in maternal blood (GM 1.77 µg/L, IQR 1.07-2.93) and urine (GM 7.42 µg/g creatinine, IQR 4.41-11.0) were highly correlated (Spearman r = 0.71, n = 166; p < 0.001) and considerably higher than reference values determined for general populations elsewhere in the world. The concentrations of Co in umbilical cord blood (GM 2.41 µg/L) were higher (Wilcoxon test, p < 0.001) than in maternal blood (GM 1.37 µg/L), with a correlation between both values (Spearman r = 0.34; n = 127, p < 0.001). Co concentrations in placental tissue (geometric mean 0.02 µg/g wet weight) correlated with concentrations in maternal blood (Spearman r = 0.50, n = 86, p < 0.001) and in neonatal blood (Spearman r = 0.23, n = 83, p = 0.039). CONCLUSION: This first study of maternal and neonatal Co concentrations in the African Copperbelt provides strong evidence of a high transfer of Co from mother to foetus.

Wolf-Hirschhorn Syndrome: Clinical and Genetic Data from a First Case Diagnosed in Central Africa.

Wolf-Hirschhorn syndrome (WHS) is a multiple congenital anomaly-intellectual disability syndrome caused by a deletion involving chromosome 4p16.3. We report clinical and genetic findings of the first WHS patient diagnosed in central Africa. This boy who presented with cleft palate, microcephaly, severe growth delay, and intellectual disability was 12 years old. Typical craniofacial features were present, though the characteristic "Greek helmet" appearance of the nose was less evident, probably reflecting a variable expression related to the genetic background. The clinical diagnosis of WHS was confirmed by array CGH, which revealed a terminal 4p16.3 deletion of 3.47 Mb, typically associated with a milder phenotype, contributing to the long survival of this child in a developing country.