Abstract:

Objective: To analyze the indications for prenatal diagnosis and postnatal follow-up outcomes in 21 fetuses diagnosed with 2q13 microdeletion syndrome. Methods: A retrospective analysis was conducted on 4 832 pregnant women who underwent amniocentesis for karyotyping and single nucleotide polymorphism array (SNP-array) testing at Prenatal Diagnosis Center of Quanzhou Women's and Children's Hospital between April 2020 and February 2024 due to various high-risk factors. Descriptive statistical methods were employed to evaluate the karyotype results, indications for invasive prenatal diagnosis, ultrasound findings, and postnatal follow-up outcomes of the 21 fetuses with 2q13 microdeletion syndrome. Results: Among the 21 fetuses identified with 2q13 microdeletion, 14 exhibited abnormal ultrasound findings; one couple were carriers of β-thalassemia; one case was flagged by noninvasive prenatal testing for sex chromosome abnormalities; one case was identified through high-risk serum screening; three cases involved advanced maternal age; and one case involved chromosomal abnormalities in both the mother and her first child. Karyotype analysis revealed that one case showed an inversion of chromosome 16, and that no abnormalities were detected in the remaining 20 cases. SNP-array testing revealed 2q13 microdeletion fragments ranging in size from 103.5 to 1 771.0 kb. Genetic testing revealed that four cases were maternally inherited, three were paternally inherited, two were de novo mutations, and twelve couples declined further verification. Four pregnancies were electively terminated after the informed decision-making based on comprehensive assessments, with no apparent external abnormalities observed in the fetuses. One case was lost to follow-up, 11 newborns were healthy at birth, and five exhibited varying degrees of congenital anomalies. Conclusions: The phenotypic manifestations of 2q13 microdeletion syndrome are highly variable, with most cases inherited from phenotypically normal parents. Genetic verification and long-term postnatal follow-up are essential for accurate clinical genetic counseling.

Key words: Prenatal diagnosis, Amniocentesis, Karyotyping, Oligonucleotide array sequence analysis, 2q13 microdeletion syndrome