Table 1.

Chromosomal instability syndromes with intrauterine growth deficiency.

Syndrome	Genes	Function in DDR	Repair pathway	Cytogenetic alteration
Fanconi anemia	21 FANC genes	ICL detection and processing, generation of adducts and DSBs (sensors, mediators and effectors)	Homologous recombination	Chromatid and chromosomal breaks Radial figures
Seckel Syndrome 1	ATR	SSBs detection and signal transduction (transducer)	Homologous recombination Nonhomologous recombination	Chromatid and chromosomal breaks and Rearrangements
Nijmegen Breakage Syndrome	NBN	DSBs detection and signaling (sensor and mediator)	Homologous recombination Nonhomologous recombination	Chromatid and chromosomal breaks Aneuploidies Rearrangements affecting chromosomes 7 and 14
Bloom Syndrome	BLM	Helicase, process SSBs, and Holliday Junctions (effector)	Homologous recombination	Quadriradials Increase in sister chromatid exchange