Mucopolysaccharidosis I (MPS I)
MPS I was the second most common type of MPS in the IMPRESsion study with 59 patients (22.7%). The two most common variants in theIDUA gene, c.1A>C and c.1598C>G, accounted for 25.4% (15/59) of the patients. Five out of the eleven patients harboring c.1A>C were from the city of Rasht in Gilan province, making this city a focal point for this variant. The rest of the patients were from the southwestern regions of Iran spanning across 5 provinces (Figure 5). This variant has previously been reported in studies conducted by Atceken et al. (2016) and Bertola et al. (2011), in patients from Turkey and Spain respectively. However, there has been no report suggestive of a founder effect for this variant.
c.1598C>G was discovered in 4 patients, three of them were from the Khorasan region in the northeast, and one was from Lorestan in the southwest of Iran (Figure 5). This variant has been discovered in Tunisian and Morroccan patients in multiple studies (Alif et al. 1999; Chkioua et al. 2011; Laradi et al. 2005), and according to Bertola et al. (2011) it has spread from North African countries to the mediterrinean regions accounting for 13% and 10% of the IDUAmutant alleles in Italy and Spain respectively.