Table 1. Summary of the sample characteristics and longitudinal phenotypic measures available at different educational time-points.
| Educational time points (N) | BG2 (169) | EG2 (170) | MG3 (170) | G6 (116) | |
| Average age (SD) | 7.47 (0.41) | 8.14 (0.37) | 8.93 (0.36) | 12.13 (0.40) | |
| Males : Females | 102:67 | 102:68 | 103:67 | 67:49 | |
| Parental education (Na) | 3.64 (130) | 3.66 (132) | 3.66 (132) | 3.63 (91) | |
| Trait | Description | Tests | |||
| WRF | Word reading fluency | DMT | DMT | EMT | EMT |
| NWRF | Nonword reading fluency | – | Klepel | Klepel | Klepel |
| RAN | Rapid naming | RANdig | RANdig | RANdig | RANdig |
| PD | Phoneme deletion | PD1 | PD1,PD2 | PD1,PD2 | PDAKT |
| NWR | Nonword repetition | – | – | NWR | – |
Abbreviations: BG2, beginning grade 2; EG2, end grade 2; MG3, middle grade 3; G6, grade 6; Na, sample size for analysis regarding mean parental education (scale of 1–5, where 1=primary education, 5=university degree).
The acronym and description for each trait of interest is indicated, together with the name of the test that has been used to measure it in each time-point. DMT and EMT: word reading fluency tests; Klepel: nonword reading fluency test; RANdig: rapid naming of digits test; PD1, PD2, and PDAKT: phoneme deletion tests. ‘–' indicates an absence of measurement at that time-point.