Prenatal diagnosis of congenital diaphragmatic hernia with mosaicism of chromosomes 17q and 18q in Iran: a case report

Abstract

Background Congenital diaphragmatic hernia is a prevalent birth defect characterized by high mortality and morbidity rates. It is defined as the protrusion of abdominal contents into the thoracic cavity through an abnormal aperture in the diaphragm of the fetus or neonate. This anomaly is multifactorial in etiology, encompassing both genetic and environmental components, and may be associated with various syndromes. Among the chromosomal abnormalities associated with congenital diaphragmatic hernia, trisomies 21, 18, and 13 are the most frequently observed. Additionally, complex chromosomal aberrations such as mosaicism have been documented. The presentation of this case underscores the novelty of identifying mosaicism involving chromosomes 17q and 18q, emphasizing the significance of genetic evaluation in elucidating congenital diaphragmatic hernia. This rare genetic finding is not extensively reported in literature. Case presentation A 34-year-old Iranian woman in her second pregnancy was referred for an ultrasound examination at the 16th week of gestation owing to the diagnosis of a fetus with a left diaphragmatic hernia containing the stomach and without the umbilical cord, accompanied by a defect in the abdominal wall. The first trimester screening tests were within normal parameters. Amniocentesis and karyotype analysis revealed mosaicism of chromosomes 17q and 18q, and the presence of a left diaphragmatic hernia was confirmed in the fetus. This rare genetic finding provides insight into potential contributing factors in the development of congenital diaphragmatic hernia. Conclusion In light of the presence of mosaicism of chromosomes in this instance, it is suggested that a potential genetic factor may play a role in the emergence of congenital diaphragmatic hernia, necessitating additional research. This case underscores the significance of genetic testing in the prenatal diagnosis of congenital diaphragmatic hernia and emphasizes the necessity for comprehensive counseling for affected families.