Medical Genetic Diagnosis and Therapy Center, Fujian Maternity and Child Health Hospital College of Clinical Medicine for Obstetrics & Gynecology and Pediatrics, Fujian Key Laboratory for Prenatal Diagnosis and Birth Defect, Fujian Medical University, Fuzhou, China.
Mol Genet Genomic Med. 2024 Jul;12(7):e2498. doi: 10.1002/mgg3.2498.
Patients with 22q11.2 microduplication syndrome exhibit a high degree of phenotypic heterogeneity and incomplete penetrance, making prenatal diagnosis challenging due to phenotypic variability. This report aims to raise awareness among prenatal diagnostic practitioners regarding the variant's complexity, providing a basis for prenatal genetic counseling.
Family and clinical data of 31 fetuses with 22q11.2 microduplications confirmed by chromosomal microarray between June 2017 and June 2023 were considered.
Primary prenatal ultrasound features of affected fetuses include variable cardiac and cardiovascular anomalies, increased nuchal translucency (≥3 mm), renal abnormalities, and polyhydramnios. More than half of fetuses considered showed no intrauterine manifestations; therefore, prenatal diagnostic indicators were primarily advanced maternal age or high-risk Down syndrome screening. Most fetuses had microduplications in proximal or central 22q11.2 regions, with only three cases with distal microduplications. Among parents of fetuses considered, 87% (27/31) continued the pregnancy. During follow-up, 19 cases remained clinically asymptomatic.
Nonspecific 22q11.2 microduplication features in fetuses and its mild postnatal disease presentation highlight the need to cautiously approach prenatal diagnosis and pregnancy decision-making. Increased clinical efforts should be made regarding providing parents with specialized genetic counseling, long-term follow-up, and fetal risk information.
22q11.2 微重复综合征患者表现出高度的表型异质性和不完全外显率，由于表型变异性，使得产前诊断具有挑战性。本报告旨在提高产前诊断从业者对该变异复杂性的认识，为产前遗传咨询提供依据。
考虑了 2017 年 6 月至 2023 年 6 月期间通过染色体微阵列确认的 31 例 22q11.2 微重复胎儿的家族和临床数据。
受影响胎儿的主要产前超声特征包括可变的心脏和心血管异常、增加的颈项透明层（≥3mm）、肾脏异常和羊水过多。超过一半的受影响胎儿在宫内没有表现；因此，产前诊断指标主要是高龄或高风险唐氏综合征筛查。大多数胎儿的微重复位于近端或中央 22q11.2 区域，只有 3 例为远端微重复。在考虑的胎儿的父母中，87%（27/31）继续妊娠。在随访中，19 例保持临床无症状。
胎儿的非特异性 22q11.2 微重复特征及其轻度的产后疾病表现突出了在产前诊断和妊娠决策时需谨慎对待。应更加努力为父母提供专门的遗传咨询、长期随访和胎儿风险信息。
