Data_Sheet_1_Etiologies of Childhood Hearing Impairment in Schools for the Deaf in Mali.PDF

Objectives: To identify the etiologies of hearing impairment (HI) in schools for students who are deaf and to use a systematic review to summarize reports on the etiologies and clinical and genetic features of HI in Mali.
Methods: We included individuals with HI that started before the age of 15 years old. Patients were carefully evaluated under standard practices, and pure-tone audiometry was performed where possible. We then searched for articles published on HI in the Malian population from the databases' inception to March 30, 2020.
Results: A total of 117 individuals from two schools for the deaf were included, and a male predominance (sex ratio 1.3; 65/52) was noted. HI was pre-lingual in 82.2% (n = 117), and the median age at diagnosis was 12 years old. The etiologies were environmental in 59.4% (70/117), with meningitis being the leading cause (40%, 20/70), followed by cases with genetic suspicion (29.3%, 21/117). In 11.3% (8/117) of patients, no etiology was identified. Among cases with genetic suspicion, three were syndromic, including two cases of Waardenburg syndrome, while 15 individuals had non-syndromic HI. An autosomal recessive inheritance pattern was observed in 83.3% of families (15/18), and consanguinity was reported in 55.5% (10/18) of putative genetic cases.
Conclusion: This study concludes that environmental factors are the leading causes of HI in Mali. However, genetic causes should be investigated, particularly in the context of a population with a high consanguinity rate.

研究目标：明确聋校聋学生听力损害（Hearing Impairment, HI）的病因，并通过系统综述（systematic review）总结马里地区该人群听力损害的病因、临床及遗传学特征。
研究方法：纳入15岁前起病的听力损害患者，按照标准临床诊疗流程对患者进行细致评估，尽可能开展纯音测听（pure-tone audiometry）检查。检索自建库起始至2020年3月30日期间发表的、针对马里人群听力损害的相关研究文献。
研究结果：共纳入来自2所聋校的117例患者，其中男性占比更高（性别比为1.3，男65例/女52例）。82.2%（n=117）的患者为语前听力损害，确诊中位年龄为12岁。59.4%（70/117）的患者病因属于环境因素，其中以脑膜炎（meningitis）最为常见（占环境病因的40%，20/70），其次为疑似遗传病因病例（占总病例的29.3%，21/117）。11.3%（8/117）的患者未明确病因。在疑似遗传病因的病例中，3例为综合征性听力损害，包括2例瓦登伯革综合征（Waardenburg syndrome），其余15例为非综合征性听力损害。18个疑似遗传病因家系中，83.3%呈现常染色体隐性遗传（autosomal recessive inheritance）模式，55.5%（10/18）的疑似遗传病例存在近亲婚配（consanguinity）史。
研究结论：本研究证实，环境因素是马里地区听力损害的首要致病因素，但遗传病因仍需进一步排查，尤其在近亲婚配率较高的人群中更应予以重视。