Table 1

Comparison of the types of CNV breakpoints identified in Drosophila and humans.

Type of breakpoint

Drosophila

Human (Conrad et al.)^a

Human (Kidd et al.)^b

Molecular mechanism(s)

n

%

n

%

n

%

Blunt

223

35

58

19

82

11

NHEJ

Microhomology

262

41

151

50

289

39

MMEJ, replication-associated repair

Blunt and large stretches of sequence identity (³20 bp)

2

0.3

3

1

219

29

SSA, NAHR, replication-associated repair

Inserted/deleted bases

143

22

81

27

153

21

NHEJ, replication-associated repair

Inserted/deleted bases and microhomology

14

2

9

3

3^c

0.4

MMEJ, replication-associated repair

Total

644

302

743

The dataset of Conrad et al. refers only to deletions while the dataset of Kidd et al. includes both deletions and insertions. Excluded from both datasets of human CNVs were those variants classified as VNTRs (variable number of tandem repeats) and as transposable elements insertions. Further excluded from the dataset of Conrad et al. were 13 deletions that were also associated with inversions. Because Conrad et al. required only 1 bp of identical sequence to call a breakpoint as being associated with microhomology, we re-classified the entire dataset so that only deletions associated with at least 2 bp of identical sequence at the breakpoint were classified as being associated with microhomology.

Cardoso-Moreira et al. Genome Biology 2012 13:R119   doi:10.1186/gb-2012-13-12-r119