The patient was a 40 year old man, who referred to our clinic because of progressive dysarthria, dysphagia and disequilibrium for the previous 15 years. According to his medical history, he had bilateral cataract surgery when he was only 2 years old and mild mental retardation since early childhood.

Background: CTX is a rare congenital lipid-storage disorder, leading to a progressive multisystem disease. CTX with autosomal recessive inheritance is caused by a defect in the CYP27A1 gene. Chronic diarrhea, tendon xanthomas, neurologic impairment, and bilateral cataracts are common symptoms of the disease. Methods: Three affected siblings with an initial diagnosis of non-syndromic intellectual disability were recruited for further molecular investigations. To identify the possible genetic cause(s), WES was performed on the proband. Sanger sequencing was applied to confirm the final variant. The clinical and molecular genetic features of the three siblings from the new CTX family and other patients with the same mutations, as previously reported, were analyzed. The CYP27A1 gene was also studied for the number of pathogenic variants and their location. Results: We found a homozygous splicing mutation, NM_000784: exon6: c. 1184+1G>A, in CYP27A1 gene, which was confirmed by Sanger sequencing. Among the detected pathogenic variants, the splice site mutation had the highest prevalence, and the mutations were mostly found in exon 4. Conclusion: This study is the first to report the c. 1184+1G>A mutation in Iran. Our findings highlight the other feature of the disease, which is the lack of relationship between phenotype and genotype. Due to nonspecific symptoms and delay in diagnosis, CYP27A1 genetic analysis should be the definitive method for CTX diagnosis.

Xanthogranulomatous osteomyelitis is a rare bone disease. Its primary presentation is similar to bone tumors.According to our research, only 3 cases of this disease have been reported in the literature. In this case report, a 22 years old patient with right thigh pain, fever and significant weight loss, associated with radiographic features resembling signs of Ewing's sarcoma is presented. The pathologic diagnosis was xanthogranulomatous osteomyelitis. The patient underwent wide spectrum antibiotic therapy and achieved complete recovery.