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Partial trisomies of 8q and 15q due to maternal balanced translocations

M Ozdemir1, Z Yuksel, K Karaer

  • 1Department of Medical Genetics, Faculty of Medicine, Eskisehir Osmangazi University, Turkey.

Genetic Counseling (Geneva, Switzerland)
|October 18, 2012
PubMed

Insights

Rare chromosomal abnormalities involving trisomies 8q and 15q are presented in two cases of unbalanced rearrangements. These rare genetic events resulted from maternal balanced translocations, leading to distinct developmental and congenital anomalies in affected infants.

Area of Science:

  • Genetics
  • Human Genetics
  • Chromosomal Abnormalities

Background:

  • Unbalanced translocations involving chromosomes 8q and 15q trisomies are exceptionally rare genetic events.
  • Maternal balanced translocations can lead to unbalanced chromosomal rearrangements in offspring.

Observation:

  • Case 1: A 4-year-old boy with speech delay, dysmorphic features (cleft lip/palate), behavioral issues, and growth retardation presented with partial 8q trisomy and partial 21p monosomy.
  • Case 2: A 2-day-old infant with ventriculomegaly, dysmorphic features, and congenital heart defects (patent ductus arteriosus, atrial septal defect) exhibited partial 15q trisomy and partial 9p monosomy.

Findings:

  • Both cases involved unbalanced chromosomal rearrangements originating from maternal balanced translocations: t(8;21) in the first and t(9;15) in the second.
  • The specific trisomies (8q, 15q) and monosomies (21p, 9p) were associated with distinct phenotypic manifestations.

Implications:

  • These cases highlight the complex and varied clinical outcomes of rare unbalanced chromosomal translocations.
  • Understanding these rare rearrangements is crucial for genetic counseling and accurate diagnosis of developmental and congenital disorders.

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