该文报道1个累及3代共9人的Nascimento型X连锁智力障碍（Nascimento form of syndromic X-linked intellectual developmental disorder, MRXSN）大家系的临床特点及基因突变类型并进行文献复习。家系中共9人有相似的智力障碍、特殊面容等，其中4人已去世。基因检测提示先证者UBE2A基因存在2~3号外显子缺失，来自母亲。荧光定量聚合酶链反应显示，先证者和表舅UBE2A基因存在2~3号外显子缺失，先证者之母亲、外婆及表姨奶UBE2A基因存在2~3号外显子杂合缺失；先证者之父亲、姐姐、表姨UBE2A基因2~3号外显子拷贝数均正常。文献报道的34例患者临床表型多样，UBE2A基因突变（22/34，65%）和大片段缺失（12/34，35%）为主要突变类型。中重度智力障碍（34/34，100%）、言语障碍（33/34，97%）、特殊面容（32/34，94%）等是MRXSN患者主要的临床表现。该病具有明显的表型异质性，尽早明确诊断有利于优生优育。

This article reports the clinical features and gene mutation types of a large family with Nascimento form of syndromic X-linked intellectual developmental disorder (MRXSN), involving 9 individuals across 3 generations, and a literature review was conducted. In this family, 9 individuals had similar manifestations including mental retardation and unusual facies, and 4 of them had passed away. Genetic testing showed that the proband had the deletion of exons 2-3 of the UBE2A gene, which was inherited from the mother. Fluorescent quantitative polymerase chain reaction showed that the proband and his uncle had the deletion of exons 2-3 of the UBE2A gene; the proband's mother, grandmother, and great-aunt had a heterozygous deletion of exons 2-3 of the UBE2A gene; the proband's father, sister, and aunt had a normal copy number of exons 2-3 of the UBE2A gene. The 34 patients reported in the literature had diverse clinical phenotypes, and UBE2A gene mutations (22/34, 65%) and large fragment deletions (12/34, 35%) were the main mutation types. Moderate to severe mental retardation (34/34, 100%), speech and language impairment (33/34, 97%), and unusual facies (32/34, 94%) were the main clinical manifestations of MRXSN patients. The disease has obvious phenotypic heterogeneity, and early diagnosis facilitates optimal prenatal and postnatal management to improve reproductive outcomes.