Copper is an essential trace element for sustaining life.
However, copper in excess is highly toxic. Although little is known about the control of copper homeostasis in mammals, recent investigations in yeast have demonstrated the involvement of various genes in copper transport and these genes provide good starting points for studies in higher organisms. Both genes encode transmembrane P-type ATPases involved in copper export. NICC is an hereditary and fatal form of infantile liver cirrhosis found with high frequency in the Tyrol. The regional localization and high frequency of NICC in the Tyrol suggests a founder effect, i.e. the patients are descendants of a common ancestor who introduced an autosomal recessive mutation into the population many generations ago.