A Case of Partial Trisomy of 10q and Partial Monosomy of 6p Resulting from Maternal t(6;10) (p23;q24)

Chromosomal analysis is practiced routinely since long time in congenital malformations to find out structural and or numerical chromosomal aberrations. Translocation is one of the structural chromosomal aberrations where exchange of genetic material between the chromosomes is seen because of two breakpoints. On the basis of involvement of type of chromosome, two different types of translocation are defined. A case of two-year-old girl child with the history of developmental delay, generalised hypotonia and recurrent infections was reported whose cytogenetic analysis showed additional genetic material on 'p' arm of one chromosome 6. To find out the additional genetic material, parental chromosomal study was done which revealed balanced translocation between 'q' arm of chromosome 10 and 'p' arm of chromosome 6 and normal chromosomal pattern in father. Balanced translocation in mother gave rise to formation of derivative chromosome 6 which was transmitted to daughter causing partial trisomy of 10q and partial monosomy of 6p. This gain and loss of genetic material could be the cause of phenotypic features. In the current case, karyotyping was an investigation of choice and offering genetic counselling regarding prenatal diagnosis in future pregnancy was a thoughtful step.