en ژنتیک/ بیوتکنولوژی Genetics/ Biotechnology پژوهشي Research <div style="text-align: justify;"><strong>Background and Aims:</strong> Retinitis pigmentosa (RP) is the most common form of inherited retinal degeneration, photoreceptors loss of which in the retina causes visual loss. The purpose of the present study was to determine patterns of inheritance in RP patients in Yazd to help the health professional for designing suitable laboratory testing for the high risk families.<br> <strong>Materials and Methods:</strong> Thirty affected RP patients referred to the Genetics Clinic of Research and Clinical Center for Infertility, in Yazd Medical Sciences University from 2010-2016. Full medical and family histories were taken from all family members. Ophthalmology examinations were performed in members of the families including electroretinogram, fundus photography, visual-field measurements and spectral domain optical coherence tomography.<br> <strong>Results</strong>: In this study, the most commonly pattern was inheritance of autosomal recessive. The patients were diagnosed as having Usher syndrome, Bardet-Biedl syndrome and Posterior Column Ataxia with Retinitis Pigmentosa. The study also reported a patient with Kreans-Sayer syndrome, a mitochondrial disease.<br> <strong>Conclusions</strong>: We identified different inheritance patterns in RP patients. Identifying patterns of inheritance is important for pre-marriage and pre-conception genetic counselling.<br> &nbsp;</div> Bardet-Biedl syndrome, Patterns of inheritance, Retinitis pigmentosa 9 14 http://ijml.ssu.ac.ir/browse.php?a_code=A-10-359-1&slc_lang=en&sid=1 Fahimeh Beigi فهیمه بیگی f.beigi@ssu.ac.ir 0000-0002-6366-8927 No Department of Medical Genetics, Shahid Sadoughi University of Medical Sciences, Yazd, Iran گروه ژنتیک Mohammad Yahya Vahidi Mehrjardi محمد یحیی وحیدی مهرجردی mmvahidi@gmail.com 0000-0003-0535-1590 No Diabetes Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. مرکز تحقیقات ژنتیک Masoud Reza Manaviat مسعود رضا معنویت mr_manaviat@yahoo.com 0000-0001-9046-0948 No Department of Ophthalmology, Shahid Sadoughi University of Medical Science, Yazd, Iran. مرکز تحقیقات دیابت Hamid Reza Ashrafzadeh حمید رضا اشرف زاده Hr.ashrafzadeh@gmail.com 0000-0001-7138-9023 No Abortion Research Centre, Yazd Reproductive Sciences Institute, Shahid Sadoughi University of Medical Sciences, Yazd, Iran مرکز تحقیقات سقط مکرر Nasrin Ghasemi نسرین قاسمی nghasemi479@yahoo.com 0000-0002-1103-6004 Yes Department of Medical Genetics, Shahid Sadoughi University of Medical Sciences, Yazd, Iran. مرکز تحقیقات سقط مکرر