Samenvatting

Purpose:
Parentally transmitted germ-line chromothripsis (G-CTH) has been identified in only a few cases. Most of these rearrangements were stably transmitted, in an unbalanced form, from a healthy mother to her child with congenital abnormalities probably caused by de novo copy-number changes of dosage sensitive genes. We describe a G-CTH transmitted through three generations in 11 healthy carriers.
Methods:
Conventional cytogenetic analysis, mate-pair sequencing, and polymerase chain reaction (PCR) were used to identify the chromosome rearrangement and characterize the breakpoints in all three generations.
Results:
We identified an apparently balanced translocation t(3;5), later shown to be a G-CTH, in all individuals of a three-generation family. The G-CTH stably segregated without occurrence of additional rearrangements; however, several spontaneous abortions were reported, possibly due to unbalanced transmission. Although seven protein-coding genes are interrupted, no clinical features can be definitively attributed to the affected genes. However, it can be speculated that truncation of one of these genes, encoding ataxia–telangiectasia and Rad3-related protein kinase (ATR), a key component of the DNA damage response, may be related to G-CTH formation.
Conclusion:
G-CTH rearrangements are not always associated with abnormal phenotypes and may be misinterpreted as balanced two-way translocations, suggesting that G-CTH is an underdiagnosed phenomenon.