It is, therefore, conceivable that the impaired DNA damage response in Clspn+/− females is analogous to DNA damage caused by alcohol consumption, obesity and smoking while primordial germ cells are being laid down in the foetal ovary, an effect which could be confounded by damage to the mitochondrial genome, and therefore only passed on by the mother [38]. This evidence concerns the gene CLSPN and obesity due to melanocortin 4 receptor deficiency.