​Background and objectives: Phenylketonuria (PKU) is a metabolic error which is caused by the deficiency of phenylalanine hydroxylase (PAH) inverting phenylalanine to tyrosine. This disease is the most common form of hyperphenyalaninaemia stow which is inherited in a form of a predominant autosomal. Therefore, the aim of this study was to investigate the distribution of occurrence of phenylketonuria disease in the world by using the systematic review and meta-analysis.

Material and Methods: The national and international databases such as Medline, CINAHL, Embase, PubMed and OVID, Google scholar, IranDOC, IranMedex, SID, Magiran, have been searched from 1990 onwards, without language restrictions and by using the key words: phenylketonuria, prevalence, incidence, congenital diseases. A total of 304 articles related with this topic were found. Finally, 62 studies were accepted. Data were analyzed by using Comprehensive Meta-Analysis software at 95% confidence level. The distribution of diseases was shown by using Geographic Information System software on the world map.

Results: The findings showed that in 100000 people, the best estimate of the disease prevalence of phenylketonuria is 11.83 (95% CI: 10.22- 13.44) and the best estimate of the incidence of this disease is 8.2 (95% CI: 6.37- 10.03) in the world. The distribution of phenylketonuria disease has the highest rate in Europe and Asia and lowest rate in Africa and America, respectively.

Conclusion: According to the findings of the present study, it can be said that there is a wide variety in the occurrence of phenylketonuria in the world and recent studies have confirmed his. Therefore, because of the irreversible consequences of the disease, the development of the appropriate training and control programs is recommended to reduce the occurrence of the disease.