To understand the current situation with the genetic epidemiology of primary congenital glaucoma (PCG) in the world, as well as to identify genotype-phenotype correlations, 87 publications were analyzed from the Pubmed and elibrary databases, mainly the latest 5 years. This publication presents the first part of the analysis, covering Arab and African countries, Turkey, the USA, Brazil, Australia and New Zealand. The second part of the review, which will be published in early 2024, will focus on data from East and South Asia, Western Europe and Russia. The highest incidence of PCG is typical for Arab countries, which is associated with the presence of a significant number of consanguineous marriages in these countries. In most countries, boys predominated among patients with PCG, and the process was often bilateral. In Australia female patients predominate. The PCG phenotype is more severe in patients with CYP1B1 mutations (early onset, bilateral involvement) than in patients without mutations, and in patients with consanguineous parents than in children from unrelated marriages. Among the genetic causes of PCG in different populations, the most common (from 30 to 86 % of cases) in Arab countries, Brazil and Turkey are mutations in the CYP1B1 gene. The spectrum of mutations varies depending on the region. In Australia and New Zealand, biallelic mutations were identified in the CYP1B1, CPAMD8 and COL18A1 genes, as well as heterozygous mutations in the TEK, FOXC1 and ANGPT1. Mutations in rare genes were also found in patients with PCG from Lebanon (ANGPT1 (p.K186N), Mauritania (NTF4 (c.601T>G, p.Cys201Gly) and WDR36 (c.2078A>G, p.Asn693Ser)). In the USA, the influence of the thrombospondin gene (THBS1) on the development of PCG is being studied. Based on the results of genetic and epidemiological studies, specific treatment, rehabilitation and preventive programs can be developed, which will determine the success of PCG therapy in children, preserving their visual functions.