Autosomal and decreased intracellular calcium due to atypical adenosine

Autosomal recessive polycystic kidney disease is classed as one of a congenital hepatorenal  fibrocystic syndrome. This disease is causative of severe liver and kidney associated mortality in children. It is commonly diagnosed in utero or at birth due to a mutation in a single gene, polycystic kidney and hepatic disease 1 (PKHD1).it is less frequent than the autosomal dominant version of the disease. Foetuses are assessed based on their severity with the most severe exhibiting ‘potter-like’ oligiohydramnios phenotype and have potentially lethal pulmonary hypoplasia with grossly enlarged echogenic kidneys which can lead to delivery complications. Nearly 50% of neonates surviving the neonatal period within the first decade of life progress to ESRD.
The gene product PKHD1 is encoded by 67 exon mRNA and codes a portion called fibrocystin. Precise function of the protein and its exact role in the kidneys is unknown.This is due to the complexity of the protein itself as it is a large with multiple transcripts with participation in multiple mulltimeric protein complexes. Studies have shown that complete lack of this gene is fatal to the embryo which supports the indication of the protein’s essential use in utero. 
Although there is lack of knowledge of the function of this protein some common phenotypes have been established. These show the pathological features which exist in a cystic epithelial cell. There are 6 characteristics (use nature for these points /original article). Epidermal growth factor (EGF) and its receptors (EGFR) have abnormalities in their expression and function. This can be related to qualitative or quantitative problems. Proliferation and decreased intracellular calcium due to atypical adenosine cyclic monophosphate signalling. Abnormal primary cilia function and structure aswell as abnormal C-terminal Src kinase. Alterations are also shown in the cell-cell matrix and planar cell polarity. 
EGFR axis abnormalities lead to cyst formation via eptherlial hyperplasia proliferation and secretion. In figure 1 it is detalied how the abnormalities cause a change in the cilia from well differnated and no prolifative features to high rate of proliferation and apoptosis which is important as it relates to cyst formation. The eptlium of the kidney is shown to have over expression  such as increase mRNA or proliferation of receptor subsequently causing activation of signalling pathways such as mitogen-activated kinase (MAPK) pathway and mislocation of the receptors. MAKE FIGURE WIDER