Academy of Medical Sciences of I.R. Iran Archives of Iranian Medicine 1029-2977 24 10 2021 10 01 The PTRHD1 Mutation in Intellectual Disability 747 751 10.34172/aim.2021.110 EN Sara Cheraghi https://orcid.org/0000-0003-2490-2757 Sahar Moghbelinejad Hossein Najmabadi Kimia Kahrizi Reza Najafipour https://orcid.org/0000-0001-6042-8314 Journal Article 10.34172/aim.2021.110 2021 01 02 2021 02 20 Background: Intellectual disability (ID) is a heterogonous disorder with complex etiology. The frequency of autosomal recessive inheritance defects was elevated in a consanguineous family. Methods: In this study, high-throughput DNA sequencing was performed in an Iranian consanguineous family with two affected individuals to find potential causative variants. Whole-exome sequencing was carried out on the proband and Sanger sequencing was implemented for validation of the likely causative variant in the family members. Results: A novel homozygous missense mutation (p.Arg122Trp) was detected in the PTRHD1 gene. Conclusion: PTRHD1 has been recently introduced as a candidate ID and Parkinsonism causing gene. Our findings are in agreement with the clinical spectrum of PTRHD1 mutations; however, our affected individuals suffer from ID manifestations.