摘要目的:探讨18例1q21.1微缺失病例的表型特征和单核苷酸多态性微阵列(SNP array)的检测结果。方法:选取18例于2017年6月至2022年12月在深圳市龙岗区妇幼保健院确诊为1q21.1微缺失综合征的病例作为研究对象，收集其临床资料。对所有病例进行1q21.1微缺失及G显带染色体核型分析。结果:在18例样本中，断裂点位于BP3和BP4区域之间者13例；位于BP1/BP2和BP4之间者4例；位于BP2和BP3之间者1例，后者为1q21.1近端缺失，涉及血小板减少伴桡骨缺失综合征(TAR)的区域。上述缺失片段约360 kb ～ 3.9 Mb，包含 CHD1L、 RBM8AB、 GJA5、 GJA8等致病基因。溯源为1q21.1微缺失病例与既往报道的病例缺失范围一致，但临床表型正常或仅轻度异常，与已报道的病例存在差异。在18例1q21.1微缺失病例中，有认知或行为缺陷者9例(9/18，50.0%)，生长发育迟缓者8例(8/18，44.4%)，头面部畸形者7例(7/18，38.8%)，心脏结构异常者5例(5/18，27.8%)，小头畸形3例(3/18，16.7%)。 结论:18例1q21.1微缺失综合征患者具有不完全外显和表现度差异，可出现智力障碍、生长发育迟缓、小头畸形等表型，其表型具有广泛的非特异性。

abstractsObjective:To explore the clinical characteristics of 1q21.1 microdeletion by using single nucleotide polymorphism microarrays (SNP array).Methods:Eighteen cases of 1q21.1 microdeletion syndrome diagnosed at the Longgang District Maternal and Child Health Care Hospital of Shenzhen City from June 2017 to December 2022 were selected as the study subjects. Clinical data of the patients were collected. Results of chromosomal karyotyping and SNP assay were retrospectively analyzed.Results:Among the 18 cases with 1q21.1 microdeletions, 13 had a deletion between BP3 and BP4, 4 had a deletion between BP1/BP2 and BP4, whilst 1 had a proximal 1q21.1 deletion (between BP2 and BP3) involving the Thrombocytopenia-absent radius (TAR) region. The deletions had spanned from 360 kb to 3.9 Mb, which encompassed the GJA5, GJA8, CHD1L, RBM8AB and other morbid genes. In three families, the proband child has inherited the same 1q21.1 microdeletion from their parents, whose clinical phenotype was normal or slightly abnormal. The clinical phenotypes of 1q21.1 microdeletion had included cognitive or behavioral deficits in 9 cases (9/18, 50.0%), growth retardation in 8 cases (8/18, 44.4%), craniofacial deformities in 7 cases (7/18, 38.8%), cardiovascular malformations in 5 cases (5/18, 27.8%), and microcephaly in 3 cases (3/18, 16.7%). Conclusion:1q21.1 microdeletion syndrome has incomplete penetrance and varied expression such as intellectual impairment, growth and development delay, and microcephaly, with a wide range of non-specific phenotypes.