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Introduction: Hereditary spastic paraplegia is a rare disease with different inheritance patterns. The prevalence of this disease is about 1.8 per 100 thousand people. Most of the affected patients are the result of consanguineous marriages. Weakness and muscle spasm is the main manifestation of this disease. The purpose of this study was to investigate the mutation analysis of a person with hereditary spastic paraplegia by the whole exome sequencing method.
Methods: Peripheral blood samples were obtained from a person suffering from gait disorder and lower limb spasm with autosomal recessive inheritance pattern. DNA extraction and whole exome sequencing was performed. After analyzing the data related to the whole exome sequence, the disease-causing mutation in the affected person was confirm using Sanger sequencing method. Also, parents were investigated to separate mutation and carrier status. This study was approved by Arak University of Medical Sciences (code IR.ARAKMU.REC.1401.039). Ethical principles have been followed in accordance with the guidelines of the National Ethics Committee and COPE regulations.
Results: In the present study, a homozygous pathogenic mutation (NM_030954.4): c.304T>C (p.Cys102Arg) in the RNF170 gene was identified in the patient, therefor, hereditary spastic paraplegia type 85 was confirmed in him. Also, the parents of the affected person were heterozygous for the mutation.
Conclusions: Homozygous mutation in RNF170 gene was detected using whole exome sequencing method. A mutation in this gene causes hereditary spastic paraplegia. Considering the consanguineous marriage of carrier parents, this finding can be used for preventive measures in future children.

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Introduction: Oculocutaneous Albinism is a hereditary disease with an autosomal recessive pattern. The incidence of this disease is about 1 in every 17 thousand births. Most of the affected people in Iran are the result of consanguineous marriages. White hair, fair skin, and reduction of iris pigments are the main manifestations of this disease. Also, exposure to sunlight increases the susceptibility of these patients to skin cancer. This study aimed to investigate the genetic cause of a person with Oculocutaneous Albinism by whole exome sequencing.
Methods: A 6cc peripheral blood sample was obtained from a child with oculocutaneous Albinism with an autosomal recessive inheritance pattern. DNA extraction and whole exome sequencing were performed. After analyzing the exome sequencing data, the pathogenic mutation was identified. Then, the Sanger sequencing method was used to confirm and segregate.
Results: The affected case showed homozygous pathogenic mutation (NM_000372.5): c.286dupA p.(Met96AsnfsTer73) in exon 1 of the TYR gene. Oculocutaneous albinism IA was determined according to the mutated gene. Also, the parents of the affected person were heterozygous for the mutation.
Conclusions: The mutation causing oculocutaneous albinism was identified in the affected person using the high-efficiency whole exome sequencing method and then confirming the mutation through Sanger sequencing. Considering the parents' consanguineous marriage of the parents, this finding can be used for preventive measures in the future.