Familial translocation, t(2;5) (p23; g31)

Area of Science:

• Human Genetics
• Cytogenetics
• Medical Genetics

Background:

• Reciprocal translocations are chromosomal abnormalities involving the exchange of segments between non-homologous chromosomes.
• Balanced translocations are typically asymptomatic in carriers but can lead to unbalanced rearrangements in offspring.

Purpose of the Study:

• To investigate the inheritance and consequences of a specific reciprocal translocation, t(2;5)(p23;q31), within a family.
• To correlate the identified chromosomal aberration with phenotypic abnormalities in affected offspring.

Main Methods:

• Karyotyping was performed to identify chromosomal abnormalities.
• Family history and phenotypic data were collected for affected and unaffected individuals.

Main Results:

• A balanced reciprocal translocation t(2;5)(p23;q31) was detected in healthy individuals across two generations.
• Two offspring in the third generation presented with malformations due to an unbalanced karyotype involving a derivative chromosome 2.
• Phenotypic abnormalities in the unbalanced offspring were consistent with those of previously deceased siblings.

Conclusions:

• The reciprocal translocation t(2;5)(p23;q31) is heritable and can result in severe developmental abnormalities in offspring with unbalanced karyotypes.
• Early cytogenetic analysis is crucial for identifying carriers and assessing recurrence risk in families with chromosomal translocations.