该文报道1例DNMT3A基因变异导致的Tatton-Brown-Rahman综合征（TBRS）的临床及遗传学特征。患儿女，8个月14 d，主要临床表现为精神运动发育迟缓、肌张力减退、脑室扩大和小脑扁桃体下疝。经基因分析发现该患儿存在DNMT3A基因新发杂合变异c.134C > T (p.A45V)，其父母该位点为野生型，根据ACMG指南判定为可能致病性变异，既往未见文献报道，符合常染色体显性遗传。该患儿确诊为TBRS。该病多数预后较好，过度生长和智力障碍是最常见的临床表现；行为/精神问题、脊柱侧弯和无热惊厥是TBRS可能的并发症。对于表现为过度生长和智力障碍的患儿，需考虑TBRS可能，必要时进行基因诊断，以免漏诊。
Abstract：This article reports the clinical and genetic features of a case of Tatton-Brown-Rahman syndrome (TBRS) caused by DNMT3A gene mutation. A girl, aged 8 months and 14 days, had the clinical manifestations of psychomotor retardation, hypotonia, ventricular enlargement, and tonsillar hernia malformation. Gene analysis identified a novel heterozygous mutation, c.134C > T(p.A45V), in the DNMT3A gene, and the wild type was observed at this locus in her parents. This mutation was determined as a possible pathogenic mutation according to the guidelines of American College of Medical Genetics and Genomics, which had not been reported in previous studies and conformed to autosomal dominant inheritance. This child was diagnosed with TBRS. TBRS often has a good prognosis, with overgrowth and mental retardation as the most common clinical manifestations, and behavioral and psychiatric problems, scoliosis, and afebrile seizures are possible complications of TBRS. The possibility of TBRS should be considered for children with overgrowth and mental retardation, and genetic diagnosis should be conducted when necessary.
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