Abstract：
BACKGROUND: Wiedemann-Steiner syndrome is caused by mutations in the KMT2A gene (11q23.3). It might be inherited autosomal dominant or appear de novo. Features described in the syndrome include developmental delay, short stature, hypotonia, hypertrichosis, facial dysmorphic features, and intellectual disability.
METHODS: A boy aged 5.5 months was admitted to the Genetics Outpatient Clinic due to delayed psychomotor development. Microsomia, hypotonia, joint laxity, and facial dysmorphic features were noticed. No genomic imbalance was found in microarray, based on comparative genomic hybridization. The c.3528G>T variant of the KMT2A gene was identified on chromosome 11 of the missense type in next-generation sequencing. The reasons for phenotypic features were confirmed in genetic research.
CONCLUSIONS: Wiedemann-Steiner syndrome has a variable clinical phenotype. There is a strong need to pay attention to phenotypic features that may suggest the syndrome and refer patients for appropriate genetic diagnostics.
METHODS: A boy aged 5.5 months was admitted to the Genetics Outpatient Clinic due to delayed psychomotor development. Microsomia, hypotonia, joint laxity, and facial dysmorphic features were noticed. No genomic imbalance was found in microarray, based on comparative genomic hybridization. The c.3528G>T variant of the KMT2A gene was identified on chromosome 11 of the missense type in next-generation sequencing. The reasons for phenotypic features were confirmed in genetic research.
CONCLUSIONS: Wiedemann-Steiner syndrome has a variable clinical phenotype. There is a strong need to pay attention to phenotypic features that may suggest the syndrome and refer patients for appropriate genetic diagnostics.
摘要：
背景：Wiedemann-Steiner综合征是由KMT2A基因（11q23.3）的突变引起的。它可能是遗传的常染色体显性遗传或从头出现。综合征中描述的特征包括发育迟缓，身材矮小,低张力,多毛症,面部畸形特征，智力残疾。
方法：一名5.5个月大的男孩因精神运动发育延迟而进入遗传学门诊。微儿,低张力,关节松弛,并注意到面部畸形特征。在微阵列中没有发现基因组失衡，基于比较基因组杂交。在下一代测序中，在错义类型的11号染色体上鉴定出KMT2A基因的c.3528G>T变体。在遗传研究中证实了表型特征的原因。
结论：Wiedemann-Steiner综合征具有不同的临床表型。非常需要注意可能提示该综合征的表型特征，并推荐患者进行适当的遗传诊断。
方法：一名5.5个月大的男孩因精神运动发育延迟而进入遗传学门诊。微儿,低张力,关节松弛,并注意到面部畸形特征。在微阵列中没有发现基因组失衡，基于比较基因组杂交。在下一代测序中，在错义类型的11号染色体上鉴定出KMT2A基因的c.3528G>T变体。在遗传研究中证实了表型特征的原因。
结论：Wiedemann-Steiner综合征具有不同的临床表型。非常需要注意可能提示该综合征的表型特征，并推荐患者进行适当的遗传诊断。
