Adenine phosphoribosyltransferase deficiency in man

Molecular variation in relation to purine metabolism

“…In this family the propositus also had hyperuricaemia, but the reduced APRT activity and the latter trait appeared to segregate independently in the family. The levels of APRT activity in the erythrocytes were similar to those observed in the first family studied, but Fox, Meade, and Kelley (1973) found that the activities of this enzyme in the leucocytes and cultured fibroblasts were normal. They were able to show that the residual APRT activity had normal heat stability and a normal half life in vivo.…”

“…These authors concluded that the condition was probably due to the operation of a mutant autosomal gene. Fox, Meade, and Kelley (1973) have described a second family with eight affected members over three generations. In this family the propositus also had hyperuricaemia, but the reduced APRT activity and the latter trait appeared to segregate independently in the family.…”

Dihydroxyadenine Urolithiasis in Children with Partial Deficiency of Adenine Phosphoribosyltransferase

“…The incidence in the population of a partial APRT deficiency has been estimated to be 0.4-1% in three sepa rate studies [12][13][14], Therefore, it seems likely that this abnormality is more common than generally considered. Although analysis of the pattern of APRT deficiency in previous reports suggests an autosomal mode of inher itance [15][16][17], this disorder is not definitely established as a primary genetic inborn error in all cases [7,14], Including our cases we have found 52 cases with partial APRT defi ciency in the literature [1,6,7,[14][15][16][17][18][19], Hyperuricemia and gout are commonly found in previously reported cases, but most of the investigators have suggested that par tial APRT deficiency has usually been an incidental finding during screening for defi ciency of HGPRT or the investigation of gout and that no characteristic clinical syndrome has been found in association with the en zyme deficiency. However, it is of great inter est that 6 of these subjects had urolithiasis of which the composition has been identified as dihydroxyadenine in 4 cases [6,7], A review of the literature to date indicates that most of the partial APRT deficiencies have been demonstrated to have a level of this enzyme higher than 20% of normal value.…”

Enzymology of Gout

“…Although some of these patients have been noted to be hyperuricemic, there does not appear to be a direct relationship between heterozygosity for adenine phosphoribosyltransferase and an aberration in purine metabolism (159). At present no disease has been unequivocally associated with this enzyme defect; however, no subjects who are homozygous for the disorder have yet been described.…”

“…Patients from four different families who are heterozygous for a deficiency of adenine phosphoribosyltransferase have been described (158)(159)(160)(161). Although some of these patients have been noted to be hyperuricemic, there does not appear to be a direct relationship between heterozygosity for adenine phosphoribosyltransferase and an aberration in purine metabolism (159).…”