[Infantile systemic hyalinosis: a case report and literature review]

Objective: To investigate the clinical, pathological and gene mutation features of infantile systemic hyalinosis(ISH). Method: Data of a child with ISH seen in Haikou Hospital were retrospectively analyzed for the diagnosis and differential diagnosis of infantile systemic hyalinosis and the relevant reports in literature were reviewed. Result: A 1 year and 1 month old boy showed limbs joint stiffness, limited mobility and double knee flexion at his first month of life. At third month, red rashes appeared on the body and gradually became purple, most of them were seen on the back and they were higher than the skin surface, uneven and did not fade when pressed. Undergoing X-ray the boy showed double knee varus deformity. Histopathological examination of the neck skin lesions proved hyalinosis. The gene examination revealed ANTXR2 exon 13, c. 1073 delC/c.1074 delT mutations, which were hot spots mutation of ISH, then the diagnosis of ISH was confirmed. Using "Infantile systemic hyalinosis" as a keyword, literature in Wanfang network, PubMed and China National Knowledge Infrastructure from 1978 to 2015 was searched, we found 48 foreign cases, one Chinese Taiwan case. All the cases had joint contractures. Short stature and skin lesions with hyperpigmentation in 40 cases, gingival hyperplasia in 36 cases, perianal nodules in 32 cases, skin thickening in 31 cases, osteoporosis in 30 cases, recurrent diarrhea in 30 cases, repeated infections in 25 cases; 49 cases were reported as autosomal recessive genetic disease, of whom 18 cases underwent genetic testing, the pathogenic gene was located in the fourth chromosome q21 position, the gene was encoded as capillary morphogenesis Protein 2 (CMG2), also known as anthrax toxin receptor 2 (ANTXR2), but there were various mutation spots in the gene. Among the 18 cases, 9 were of frameshift, 8 of missense and 1 of splice defect . Onset ages were mainly within 4 months after birth. Without special treatment most patients died at about 2 years of age due to repeated infections. Conclusion: ISH is a rare disease, which occurs at early age. ISH has special clinical features: joint contracture and limited mobility, special skin rash and pigmentation, skin hyaline degeneration of pathological examination. ISH is an autosomal recessive genetic disease with mutation gene located in the fourth chromosome q21 position. Currently there is no effective treatment for ISH, with which patients are prone to die of recurrent infections.