Mardi Ali, Heidary Hamed, Mousavi Seyyed Mohammad, Khazaei Ghasem, Taghizadeh Eskandar
Department of Medical Genetics, Ali Asghar Hospital, Iran University of Medical Sciences, Tehran, Iran.
Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran.
Iran J Public Health. 2021 Sep;50(9):1897-1901. doi: 10.18502/ijph.v50i9.7063.
Cystinuria is an autosomal recessive disorder in which the renal reabsorption of cystine, arginine, lysine and ornithine are disturbed. The two genes, the pathogenic forms of which are responsible for the disorder, are SLC7A9 and SLC3A1. In this study, we describe a disease that has a new c.916A> T variant (p. K306 *) in exon 5 of the SLC3A1 gene. This variant results in the NMD phenomenon in which the protein product is not produced because of mRNA destruction. In 2020, blood sample of a 41-yr-old man from east Azerbaijan, Iran together with his parents were collected to be studied. PCR and direct sequencing were performed to detect the possible SLC3A1 variant. Whole-gene sequence analysis done by Mutation surveyor Software revealed a novel nonsense homozygous variant in exon 5 of the gene. Parental Sequence Analysis shows that they are heterozygous. According to ACMG guideline, this variant is considered as pathogen. Finding serious mutations can allow rapid screening for cystinuria by analyzing common mutations. It should also be considered as a pathogenic variant in patients' cystinuria.
胱氨酸尿症是一种常染色体隐性疾病，其中胱氨酸、精氨酸、赖氨酸和鸟氨酸的肾脏重吸收受到干扰。导致该疾病的两种致病基因是SLC7A9和SLC3A1。在本研究中，我们描述了一种疾病，其在SLC3A1基因的第5外显子中有一个新的c.916A>T变体（p.K306*）。该变体导致无义介导的mRNA降解（NMD）现象，即由于mRNA被破坏而无法产生蛋白质产物。2020年，采集了一名来自伊朗东阿塞拜疆省的41岁男性及其父母的血样进行研究。进行聚合酶链反应（PCR）和直接测序以检测可能的SLC3A1变体。通过Mutation surveyor软件进行的全基因序列分析揭示了该基因第5外显子中一个新的纯合无义变体。亲代序列分析显示他们是杂合子。根据美国医学遗传学与基因组学学会（ACMG）的指南，该变体被认为是致病性的。发现严重突变可以通过分析常见突变来快速筛查胱氨酸尿症。它也应被视为患者胱氨酸尿症中的致病变体。
