Table 2.

Genomic Disorders that Exhibit Microcephaly and Growth Retardation Associated with Hemizygous Deletions of ATR Pathway Components

Disorder	Chromosome Deletion	ATR-Pathway Component	ATR-Dependent Cellular Features
BPES-ATR+/-	3q23	ATR	Defective ATR-dependent γH2AX formation, Chk1 phosphorylation and G2-M arrest
Isolated Lissencephaly Sequence	17p13.3	RPA1	Defective ATR-dependent γH2AX formation, Chk1 phosphorylation and G2-M arrest
Miller-Dieker Lissencephaly Syndrome	17p13.3	RPA1	Defective ATR-dependent γH2AX formation, Chk1 phosphorylation and G2-M arrest
Williams-Beuren Syndrome	7q11.23	RFC2	Defective ATR-dependent G2-M arrest