Primary hyperoxaluria type 1 (PH1) is caused by a deficiency of the liver peroxisomal enzyme alanine:glyoxylate-aminotransferase (AGT), which catalyzes the conversion of glyoxylate to glycine. When AGT activity is absent, glyoxylate is converted to oxalate, which forms insoluble calcium oxalate crystals that accumulate in the kidney and other organs. Individuals with PH1 are at risk for recurrent nephrolithiasis (deposition of calcium oxalate in the renal pelvis / urinary tract), nephrocalcinosis (deposition of calcium oxalate in the renal parenchyma), or end-stage renal disease (ESRD). Age at onset of symptoms ranges from infancy to the sixth decade. Approximately 10% of affected individuals present in infancy or early childhood with nephrocalcinosis, with or without nephrolithiasis, and failure to thrive related to renal failure. The majority of individuals with PH1 present in childhood or early adolescence, usually with symptomatic nephrolithiasis and normal or reduced kidney function. The remainder of affected individuals present in adulthood with recurrent renal stones and a mild-to-moderate reduction in kidney function. The natural history of untreated PH1 is one of progressive decline in renal function as a result of calcium oxalate deposits in kidney tissue and complications of nephrolithiasis (e.g., obstruction and infection) with eventual progression to oxalosis (widespread tissue deposition of calcium oxalate) and death from ESRD and/or complications of oxalosis.

An autoimmune disorder characterized by the association of primary biliary cirrhosis with limited cutaneous systemic sclerosis. Onset occurs between 30-65 years. Occurs sporadically, but rare familial cases with an unknown inheritance pattern have been observed. There is no cure and management is mainly supportive.

Cole disease (COLED) is a rare autosomal dominant disorder characterized by congenital or early-onset punctate keratoderma associated with irregularly shaped hypopigmented macules, which are typically found over the arms and legs but not the trunk or acral regions. Skin biopsies of palmoplantar lesions show nonspecific changes including hyperorthokeratosis, hypergranulosis, and acanthosis. Hypopigmented areas of skin, however, reveal a reduction in melanin content in keratinocytes but not in melanocytes, as well as hyperkeratosis and a normal number of melanocytes. Ultrastructurally, melanocytes show a disproportionately large number of melanosomes in the cytoplasm and dendrites, whereas keratinocytes show a paucity of these organelles, suggestive of impaired melanosome transfer (summary by Eytan et al., 2013). Some patients also exhibit calcinosis cutis or early-onset calcific tendinopathy (Eytan et al., 2013).