en Molecular Genetics & Genomics Molecular Genetics & Genomics مقاله موردی Case Report Chanarin-Dorfman syndrome (CDS) is a rare autosomal recessive metabolic disorder caused by mutations in gene encoding the domain-5 of &alpha;/&beta;-hydrolase enzyme (<em>ABHD5</em>). It is known as a natural lipid storage disorder arising from impaired lipid metabolism often characterized by hepatomegaly, myopathy, ataxia, non-bullous ichthyosiform erythroderma, hearing loss, and mental retardation. In the present study, we report two affected 28-month-old monozygotic twin boys as new cases of CDS. Genetic analysis was performed in patients, and the results showed a homozygote deletion in exon 4 of <em>ABHD5</em>. According to the the American College of Medical Genetics and Genomics, this variant is categorized as a pathogenic variant. Ichthyosiform, Hepatomegaly, Ichthyosis 415 419 http://ibj.pasteur.ac.ir/browse.php?a_code=A-10-1-716&slc_lang=en&sid=1 Shahrbanoo Nakhaei 0000-0003-2899-3780 No Department of Pediatrics, Faculty of Medicine, Ali Asghar Children Hospital, Iran University of Medical Sciences (IUMS), Tehran, Iran Hamed Heidary 0000-0002-9141-887x No Department of Pediatrics, Faculty of Medicine, Ali Asghar Children Hospital, Iran University of Medical Sciences (IUMS), Tehran, Iran Aliasghar Rahimian 0000-0003-2423-1455 No Department of Medical Biochemistry, Tehran University of Medical Sciences, Tehran, Iran Mahdi Vafadar 0000-0000-0000-0000 No Department of Pediatrics, Faculty of Medicine, Ali Asghar Children Hospital, Iran University of Medical Sciences (IUMS), Tehran, Iran Farzaneh Rohani 0000-0000-0000-0000 No Pediatric Growth and Development Research Center, Iran University of Medical Sciences, Tehran, Iran G.R. Bahoosh 0000-0000-0000-0000 No Department of Pediatrics, Faculty of Medicine, Ali Asghar Children Hospital, Iran University of Medical Sciences (IUMS), Tehran, Iran Davoud Amirkashani 0000-0002-0838-3005 Yes Department of Pediatrics, Faculty of Medicine, Ali Asghar Children Hospital, Iran University of Medical Sciences (IUMS), Tehran, Iran