Noonan's syndrome associated with hypoplastic left heart

Area of Science:

• Pediatric Cardiology
• Clinical Genetics
• Neonatal Medicine

Background:

• Turner's syndrome is a genetic condition typically associated with a 45,X karyotype.
• Congenital heart defects are common in Turner's syndrome, significantly impacting neonatal outcomes.

Observation:

• A one-week-old female infant exhibited apathy, hypothermia, dyspnea, jaundice, and cyanosis.
• The infant presented with a phenotype suggestive of Turner's syndrome but had a normal karyotype (46,XX).
• Clinical signs indicated severe heart failure unresponsive to medical and ventilatory support.

Findings:

• Autopsy revealed complex congenital heart defects: hypoplastic left heart syndrome with mitral and aortic atresia.
• Additional findings included an atrial septal defect, double outlet right ventricle, and a patent ductus arteriosus.
• The combination of a Turner's-like phenotype and a normal karyotype in the context of severe congenital heart disease is noteworthy.

Implications:

• This case highlights the importance of considering complex congenital heart disease even in the presence of a normal karyotype in neonates with features suggestive of chromosomal abnormalities.
• The findings underscore the challenges in diagnosing and managing severe congenital heart defects in neonates presenting with atypical genetic profiles.
• Further research may explore the genetic and etiological factors contributing to this specific constellation of findings.