Background: The ichthyosis is a hereditary skin disease and inherited by autosomal dominant, autosomal recessive and X recessive trait separately. The X-linked ichthyosis (XLI) is the most frequent cutaneous disease and general incidence accounts for one in 2000-5000 male births. Molecular pathogenesis of XLI is due to mutations, which are large deletion, missense, frame shift and nonsense in STS gene. The vast majority of mutation frequency is a large deletion, which are found in 85-90% of patients with XLI. An exon deletion of the STS can be detected by Polymerase chain reaction with exon specific primers. An identification of STS gene mutation has various importance such as 1) detection of mutation type; 2) for genetic counselling, 3) disease severity, 4) carrier detection. Methods: In the present study, pedigree analysis was used for type of inheritance, and Polymerase chain reaction was used to detect a deletion in STS gene and normal control used. A deletion was identified in case PCR bands were not visualized in agarose gels. Results: We included one patient, who had typical symptoms of XLI including dark, adherent scales on skin. Mutation analysis of the STS gene showed that the patient had whole gene deletion (del: Exon 1-10), which was demonstrated by the repeated amplification failure of exons. We used a sample of healthy man as a wild type control, which showed normal amplification of STS gene’s exons. Further, the current study will be focused on the screening of heterozygote large deletion of Del: Exon1-10 of STS gene among patient’s female relatives. Conclusion An ichthyosis case enrolled in this study was inherited by X-recessive and we identified whole exon deletion of STS gene in this patient.