SMN1 and Zinc deficiency: It was also shown in rats that zinc deficiency in the dam results in foetuses with heart anomalies because of the alterations in the expression and distribution of several proteins involved in its development, including human natural killer-1 (HNK-1), Connexin-43 (Cx43), survival of motor neuron 1 (SMA), GATA-4 and FOG-2 [69].