X-linked recessive ichthyosis with X-linked retinoschisis in two brothers: a case report
Source: PubMed Central Open Access, NCBI / U.S. National Library of Medicine
Background X-linked ichthyosis (XLI) and X-linked retinoschisis (XLRS) are both inherited in an X-linked recessive manner. To date, no prior reports document both conditions’ simultaneous occurrence. This case presents two brothers who were diagnosed with XLI combined with XLRS in a family. Case presentation An 11-year-old boy (Case 1) presented to our hospital due to decreased bilateral vision detected during a physical examination over the past month. One month after birth, the parents noticed the child’s skin was dry and rough. He was diagnosed with “ichthyosis” at another hospital, and after treatment, the condition improved. His mother had also been previously diagnosed with ichthyosis. The child was a full-term infant delivered by cesarean section, and his parents were not closely related. There was no family history of eye disease. Physical examination showed dry skin with diamond-shaped scales. The best-corrected visual acuity was 0.40 logMAR in both eyes. No abnormalities were observed in the anterior segments of both eyes. Fundus examination revealed petaloid macular edema, and OCT showed numerous cystic changes in the macular area of both eyes. His 6-year-old younger brother (Case 2) exhibited similar systemic and ocular features. Comprehensive ophthalmic and genetic examinations were performed on the entire family, revealing that both children carried an RS1 gene mutation, with the mutation site at c.545G>T/p.Arg182Leu, inherited from their mother. Additionally, a
Abstract
Background X-linked ichthyosis (XLI) and X-linked retinoschisis (XLRS) are both inherited in an X-linked recessive manner. To date, no prior reports document both conditions’ simultaneous occurrence. This case presents two brothers who were diagnosed with XLI combined with XLRS in a family. Case presentation An 11-year-old boy (Case 1) presented to our hospital due to decreased bilateral vision detected during a physical examination over the past month. One month after birth, the parents noticed the child’s skin was dry and rough. He was diagnosed with “ichthyosis” at another hospital, and after treatment, the condition improved. His mother had also been previously diagnosed with ichthyosis. The child was a full-term infant delivered by cesarean section, and his parents were not closely related. There was no family history of eye disease. Physical examination showed dry skin with diamond-shaped scales. The best-corrected visual acuity was 0.40 logMAR in both eyes. No abnormalities were observed in the anterior segments of both eyes. Fundus examination revealed petaloid macular edema, and OCT showed numerous cystic changes in the macular area of both eyes. His 6-year-old younger brother (Case 2) exhibited similar systemic and ocular features. Comprehensive ophthalmic and genetic examinations were performed on the entire family, revealing that both children carried an RS1 gene mutation, with the mutation site at c.545G>T/p.Arg182Leu, inherited from their mother. Additionally, a deletion variant of approximately 478 kb was found at the X chromosome p22.31 location, completely covering the STS gene region. Based on the genetic testing and ocular examination, both children were finally diagnosed with bilateral XLRS and XLI. Conclusion This case expands the mutation spectrum of XLRS in Chinese patients and, for the first time, reports the ocular and systemic manifestations when two different disease genes, STS and RS1, coexist. The family members vividly demonstrate the phenotypic and genotypic individual heterogeneity associated with hereditary eye diseases. A comprehensive analysis of clinical phenotype and genotype improves clinical diagnosis and genetic testing accuracy, providing a clinical approach for a more comprehensive understanding of the disease.