De novo trisomy 16p11.2-qter: report of an infant

M Masuno1, T Ishii, Y Tanaka

  • 1Division of Medical Genetics, Kanagawa Children's Medical Center, Yokohama, Japan.

Insights

A rare de novo trisomy 16q genetic condition caused multiple severe congenital anomalies in a four-month-old girl. The extra chromosome 16 segment was maternally inherited, highlighting complex genetic inheritance patterns.

Area of Science:

  • Genetics
  • Developmental Biology
  • Pediatrics

Background:

  • Trisomy 16q is a rare chromosomal abnormality.
  • De novo genetic mutations can lead to significant congenital malformations.
  • Understanding chromosomal abnormalities is crucial for diagnosing and managing genetic disorders.

Observation:

  • A four-month-old female infant presented with de novo trisomy 16q.
  • The infant exhibited facial and limb anomalies, urogenital abnormalities, and severe cardiovascular defects.
  • Autopsy revealed complex internal anomalies including hypoplastic lung and total anomalous pulmonary venous drainage.

Findings:

  • The patient had a karyotype of 47,XX, +del(16)(p11.2).
  • Autopsy confirmed multiple congenital anomalies: left hypoplastic lung, total anomalous pulmonary venous drainage via coronary sinus, persistent left superior vena cava, patent ductus arteriosus, secundum atrial septal defect, bilateral hydronephrosis and hydroureters, uterus bicornis, and ovarian hypoplasia.
  • Short tandem repeat polymorphism analysis identified the additional, structurally abnormal chromosome 16 as maternal in origin.

Implications:

  • This case expands the phenotypic spectrum associated with trisomy 16q.
  • It underscores the importance of detailed genetic analysis and autopsy in cases of complex congenital anomalies.
  • Further research into trisomy 16q may elucidate specific gene functions and developmental pathways affected by this condition.

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