48,XXYY综合征合并糖尿病1例的X染色体来源和失活偏移分析

目的 初步探讨48,XXYY综合征合并糖尿病患者的临床特点,并分析该疾病的X染色体来源和失活偏移.方法收集患者的临床资料,抽提患者及其父母的外周血基因组DNA,应用PCR结合HpaⅡ限制性内切酶消化法分析X染色体来源和失活偏移.结果 患者临床表现及实验室检查完全符合48,XXYY综合征,使用二甲双胍和睾酮治疗后患者血糖控制平稳.患者X染色体分别来源于父亲和母亲,两条X染色体均为部分失活,偏移度为0.52.结论 48,XXYY综合征合并糖尿病的发病机制可能与睾酮水平低下、胰岛素抵抗有关.48,XXYY综合征多余X染色体来源于父亲,X染色体不一定存在失活偏移.

A case of 48, XXYY syndrome with diabetes and analysis of the parental origin of X chromosome and skewed X-inactivation

Objective: To explore the clinical features of 48, XXYY syndrome with diabetic; to analyze parental origin of X-chromosome and skewed X-inactivation. Methods: The clinical data were collected; Genomic DNA was extracted from a whole blood sample. The parental origin of X chromosome and skewed X-inactivation were analyzed using PCR combined Hpa Ⅱ restriction enzyme digestion. Results: The patient was diagnosed as 48, XXYY syndrome with diabetes according to the clinical presentations and laboratory examinations. Plasma glucose level remained stable after metformin plus testosterone treatment. The X chromosome were inherited from the patient’ father and mother. The degree of skew of X-inactivation was 0.52. Conclusion: The pathogenesis of diabetes in 48,XXYY patient may be associated with low testosterone levels and insulin resistance. The extra X chromosome of our case and other had reported eight cases of 48, XXYY syndrome were paternal origin. Not all of 48,XXYY syndrome patients had skew X-inactivation.