| Study name | Age when effect size was coded family-risk (control) | Sample size Group 1 (Group 2) | Construct (outcome test) | Effect size (d) | Prevalence of dyslexia (in family-risk sample/in control sample without family risk) | Recruitment of relatives with dyslexia | Socioeconomic status |
|---|---|---|---|---|---|---|---|
| Note. BAS = British Ability Scales; Bayley MDI = Bayley Mental Developmental Index; BNT = Boston Naming Test; BPVS = British Picture Vocabulary Scale; CELF = Clinical Evaluation of Language Fundamentals; CN Rep = Children’s Test of Nonword Repetition; Comp = comprehension; DAS = Differential Ability Scales; CPM = Colored Progressive Matrices; DEAP = Diagnostic Evaluation of Articulation and Phonology; GORT = Gray Oral Reading Tests; K-BIT = Kaufman Brief Intelligence Test; m-ABC = Movement Assessment Battery for Children; M CDI = MacArthur-Bates Communicative Development Inventories; NARA = Neale Analysis of Reading Ability; NEPSY = Developmental Neuropsychological Assessment; PA = phonological awareness; PCC = percentage consonants correct; Phon Aw = phonological awareness; Phon memory = phonological memory; PPVT = Peabody Picture Vocabulary Test; RAN = rapid naming; SON-R = Snijders-Oomen nonverbal intelligence tests; vSTM = verbal short-term memory; WAIS = Wechsler Adult Intelligence Scale; WPPSI = Wechsler Preschool and Primary Scale of Intelligence; WISC = Wechsler Intelligence Scale for Children; WJ = Woodcock Johnson; WOLD = Wechsler Objective Language Dimensions; WORD = Wechsler Objective Reading Dimensions; Word ID = word identification; WRMT = Woodcock Reading Mastery Tests; YARC = York Assessment of Reading for Comprehension. | |||||||
| Blomert & Willems, 2010 | Kgarten | 53 (47) | Dyslexia versus controls: | 44%/.09% | Parental questionnaire, sibling with a diagnosis of dyslexia | — | |
| Articulatory accuracy (pronounce a word correctly after parts have been deleted) | .09 | ||||||
| IQ (general intelligence test not specified) Verbal short term memory (word span) | |||||||
| Receptive vocabulary (test not specified) | .19 | ||||||
| Letter knowledge (correctly name or sound out visual presented letters) | .18 | ||||||
| Phon Aw (blend phonemes or phoneme strings) | .37 | ||||||
| .11 | |||||||
| .10 | |||||||
| Boets, De Smedt, et al., 2010 (1) | Dyslexia versus controls: | — | Maternal and paternal education are measured | ||||
| 5.33 (5.33) | 16 (26) | IQ (Raven) | −.32 | ||||
| Phon Aw (composite PA) | −1.37 | ||||||
| Phon memory (CN Rep) | −1.23 | ||||||
| RAN (colors and objects) | −.80 | ||||||
| vSTM (digit span) | −.40 | ||||||
| 1st grade | Vocabulary knowledge (WISC vocabulary) | −.49 | |||||
| Nonword reading (nonword reading fluency) | −1.56 | ||||||
| Paternal education | .31 | ||||||
| Maternal education | .00 | ||||||
| Unaffected family-risk versus controls: | 44% | — | Maternal and paternal education are measured | ||||
| 5.33 (5.33) | 20 (26) | IQ (Raven) | −.32 | ||||
| Phon Aw (composite PA) | −.52 | ||||||
| Phon memory (CN Rep) | −.65 | ||||||
| RAN (colors and objects) | −.32 | ||||||
| vSTM (digit span) | .25 | ||||||
| 1st grade | Vocabulary knowledge (WISC vocabulary) | −.40 | |||||
| Nonword reading (nonword reading fluency) | −.27 | ||||||
| Paternal education | −.28 | ||||||
| Maternal education | .00 | ||||||
| Boets, Vandermosten, et al., 2011 (1) | 5:6 (5:6) | 16 (26) | Dyslexia versus controls: | 44% | — | Groups matched on parental education level | |
| IQ (WISC III block design) | .00 | ||||||
| Vocabulary knowledge (WISC III vocabulary) | −.40 | ||||||
| Spelling (spelling test Dudal, 1997) | −1.92 | ||||||
| 6:10 (6:10) | Word reading (word reading test) | −2.53 | |||||
| 20 (26) | Unaffected family-risk versus controls: | Matched | |||||
| 5:6 (5:6) | IQ (WISC III block design) | .00 | |||||
| Language comprehension (WISC III vocabulary) | .00 | ||||||
| 6:10 (6:10) | Spelling (spelling test Dudal, 1997) | −.59 | |||||
| Word reading (word reading test) | −.43 | ||||||
| Boets, Wouters, van Wieringen, et al., 2007 (1) | Dyslexia versus controls: | 29%/.09% | At least one first-degree relative diagnosed with dyslexia | Significant differences in maternal or paternal level between the at-risk group and the control group | |||
| 63 (64) | 9 (28) | Rhyme awareness (rhyme identity) | −1.00 | ||||
| Auditory processing (speech perception) | −.80 | ||||||
| IQ (Raven CPM) | −.23 | ||||||
| Phon Aw (composite phoneme and rhyme identity tasks) | −1.29 | ||||||
| Phon memory (Dutch adaption of CN Rep) | −.85 | ||||||
| RAN (rapid naming of colors and objects) | −.95 | ||||||
| 64 (64) | 22 (28) | Unaffected family-risk versus controls: | — | At least one first-degree relative diagnosed with dyslexia | |||
| Rhyme awareness (rhyme identity) | −.21 | ||||||
| Auditory processing (speech perception) | −.55 | ||||||
| IQ (Raven CPM) | −.33 | ||||||
| Phon Aw (composite phoneme and rhyme identity tasks) | −.65 | ||||||
| Phon memory (Dutch adaption of CN Rep) | −.67 | ||||||
| RAN (rapid naming of colors and objects) | −.50 | ||||||
| Carroll, Mundy, & Cunningham, 2014 | 67.67 (64.12) | 78 (17) | Dyslexia versus controls: | 44.7%/17% | At least one first-degree relative diagnosed with dyslexia after a professional assessment | ||
| Articulatory accuracy (judging pronunciation of words) | −1.09 | ||||||
| Phon Aw (phoneme matching) | −.83 | ||||||
| Phon memory (CN Rep) | −1.27 | ||||||
| Vocabulary knowledge (CELF) | −1.34 | ||||||
| Letter knowledge | −.51 | ||||||
| Word reading (YARC) | −2.81 | ||||||
| Reading comprehension (YARC) | −1.11 | ||||||
| 78 (21) | Unaffected family-risk versus controls: | ||||||
| Articulatory accuracy (judging pronunciation of words) | −.34 | ||||||
| Phon Aw (phoneme matching) | −.11 | ||||||
| Phon memory (CN Rep) | −.07 | ||||||
| Vocabulary knowledge (CELF) | −.37 | ||||||
| Letter knowledge | −.00 | ||||||
| Word reading (YARC) | −.51 | ||||||
| Reading comprehension (YARC) | −.42 | ||||||
| de Bree, Wijnen, & Gerrits, 2010 (13) | Dyslexia versus controls: | −1.16 | 50%/22% | Standardized tests of parents | — | ||
| 4:4 (4:5) | 19 (23) | Phon memory (Dutch version of Dollaghan & Campbell, 1998) | |||||
| Unaffected family-risk versus controls: | — | Standardized tests of parents | — | ||||
| 4:4 (4:5) | 19 (23) | Phon memory (Dutch version of Dollaghan & Campbell, 1998) | −.66 | ||||
| Elbro & Petersen, 2004 (4) | 7th grade | 47 (41) | Only prevalence included in the meta-analysis since test data were reported for at-risk children versus controls | — | 55%/20% | Self-report and test | Fathers in the not-at-risk group had significantly higher education than fathers in the at-risk group |
| Elbro, Borstrøm, & Petersen, 1998 (4) | Dyslexia versus controls: | 37%/11% | Self-report and test | Fathers in the not-at-risk group had significantly higher education than fathers in the at-risk group | |||
| 2nd grade | 18 (42) | Articulatory accuracy (articulatory skills) grammar (inflection formation) IQ (Raven) letter knowledge | −.59 | ||||
| Phon Aw (phoneme discrimination) RAN (picture naming) vocabulary knowledge (language PPVT) | −.59 | ||||||
| vSTM (WISC-R) | −.26 | ||||||
| −1.17 | |||||||
| −.89 | |||||||
| −.48 | |||||||
| −.90 | |||||||
| −.81 | |||||||
| Unaffected family-risk versus controls: | Self-report and test | Fathers in the not-at-risk group had significantly higher education than fathers in the at-risk group | |||||
| 2nd grade | 31 (42) | Articulatory accuracy (articulatory skills) | −.59 | ||||
| Grammar (inflection formation) | −.27 | ||||||
| IQ (Raven) | −.26 | ||||||
| Letter knowledge | −.63 | ||||||
| Phon Aw (phoneme discrimination) | −.47 | ||||||
| RAN (picture naming) | −.51 | ||||||
| Vocabulary knowledge (language PPVT) | −.37 | ||||||
| vSTM (WISC-R) | −.20 | ||||||
| Gallagher, Frith, & Snowling, 2000 (5) | Dyslexia versus controls: | 66%/16% | Confirmed with standardized testing | Middle-class volunteer sample | |||
| 6 years (6 years) | 63 (34) | Rhyme awareness (rhyme knowledge) vSTM (digit span forward) | −1.00 | ||||
| 45 months | −1.35 | ||||||
| Unaffected family-risk versus controls: | 66%/16% | Confirmed with standardized testing | Middle-class volunteer sample | ||||
| 6 years (6 years) | Rhyme awareness (rhyme knowledge) vSTM (digit span forward) | −.22 | |||||
| 45 months | −.35 | ||||||
| Ho, Leung, & Cheung, 2011 | 36 (25) | Dyslexia versus controls: | 47% | Confirmed with standardized testing | At-risk parents had significantly lower education and income than the controls | ||
| 5:9 (6:18) | IQ (Raven CPM) | .55 | |||||
| Vocabulary knowledge (adapted word definitions) | −.67 | ||||||
| Vocabulary knowledge (picture vocabulary) | −1.17 | ||||||
| Phon Aw (syllable deletion) | −1.36 | ||||||
| RAN (rapid naming of colors and objects) | −.58 | ||||||
| Spelling (Chinese spelling) | −2.40 | ||||||
| Word reading (Chinese word reading) | −1.82 | ||||||
| 40 (25) | Unaffected family-risk versus controls: | Confirmed with standardized testing | At-risk parents had significantly lower education and income than the controls | ||||
| 6:6 (6:18) | IQ (Raven CPM) | −.17 | |||||
| Vocabulary knowledge (adapted word definitions) | −.14 | ||||||
| Vocabulary knowledge (picture vocabulary) | −.29 | ||||||
| Phon Aw (syllable deletion) | −.23 | ||||||
| RAN (rapid naming of colors and objects) | −.05 | ||||||
| Spelling (Chinese spelling) | −.11 | ||||||
| Word reading (Chinese word reading) | .15 | ||||||
| Leppänen, Hämäläinen, et al., 2010 (3) | Dyslexia versus controls: | — | Confirmed with standardized testing | — | |||
| 3.5 (3.5) | 8 (25) | Phon Aw (composite PA) | −.85 | ||||
| 5.0 (5.0) | vSTM (composite vSTM) | −.86 | |||||
| 5.5 (5.5) | RAN (composite RAN) | −1.61 | |||||
| 9.0 (9.0) | Word reading (composite word reading accuracy and fluency) | −2.78 | |||||
| Spelling (composite) | −1.94 | ||||||
| Unaffected family-risk versus controls: | — | Confirmed with standardized testing | |||||
| 3.5 (3.5) | 14 (25) | Phon Aw (composite) | −.83 | ||||
| 5.0 (5.0) | vSTM (composite) | −.39 | |||||
| 5.5 (5.5) | RAN (composite) | −.15 | |||||
| 9.0 (9.0) | Spelling (composite) | −.02 | |||||
| Word reading (composite word reading accuracy and fluency) | −.05 | ||||||
| McBride-Change et al., 2011 (9) | Dyslexia versus controls: | Merged at-risk sample, both family-risk and delayed language development | — | ||||
| Kgarten | 26 (47) | IQ (not specified) | .23 | ||||
| Phon Aw (syllable deletion) | −.54 | ||||||
| RAN (digits) | −1.13 | ||||||
| Visual skills (Gardener test of visual perception) | −.34 | ||||||
| 7:3 | Word reading (Chinese character reading) | −2.50 | |||||
| Unaffected family-risk versus controls: | Merged at-risk sample, both family-risk and delayed language development | — | |||||
| Kgarten | 21 (47) | IQ (not specified) | .03 | ||||
| Phon Aw (syllable deletion) | −.41 | ||||||
| RAN (digits) | −.56 | ||||||
| Visual skills (Gardener test of visual perception) | −.08 | ||||||
| 7:3 | Word reading (Chinese character reading) | −.33 | |||||
| Pennala, Eklund, et al., 2010 (3) | 3rd grade | 33 (77) | Dyslexia versus controls: | — | |||
| Phon memory (NEPSY nonrep) | −.21 | Confirmed with standardized testing | |||||
| RAN (naming speed composite) | −.70 | ||||||
| Spelling (word spelling) | −1.85 | ||||||
| Word reading (word reading accuracy) | −2.39 | ||||||
| 3rd grade | 68 (80) | Unaffected family-risk versus controls: | Confirmed with standardized testing | — | |||
| Phon memory (nonrep NEPSY) | −.05 | ||||||
| RAN (nonrep composite) | −.00 | ||||||
| Spelling (word spelling) | −.37 | ||||||
| Word reading (word reading accuracy) | −.28 | ||||||
| Pennington & Lefly, 2001 (6) | Dyslexia versus controls | 34%/.06% | Reading history questionnaire that in cases of doubt were supplemented by testing | Matched on SES | |||
| 5:4 (5:3) | 22 (54) | Letter knowledge (letter name knowledge) | −1.32 | ||||
| 5:4 (5:3) | 42 (54) | Unaffected family-risk versus controls: | Reading history questionnaire that in cases of doubt were supplemented by testing | Matched on SES | |||
| Letter knowledge (letter names) | −.08 | ||||||
| End of second grade | 22 (54) | Dyslexia versus controls: | Reading history questionnaire that in cases of doubt were supplemented by testing | Matched on SES | |||
| IQ (WISC vocabulary and block design subtests) | −.31 | ||||||
| Nonword reading (WJ word attack) | −1.29 | ||||||
| Spelling (WRAT spelling) | −1.89 | ||||||
| Word reading (WJ letter word identification) | −1.75 | ||||||
| End of second grade | 42 (54) | Unaffected family-risk versus controls: | Reading history questionnaire that in cases of doubt were supplemented by testing | Matched on SES | |||
| IQ (WISC vocabulary and block design subtests) | −.22 | ||||||
| Nonword reading (WJ word attack) | −.39 | ||||||
| Spelling (WRAT spelling) | −.69 | ||||||
| Word reading (WJ letter word identification) | −.50 | ||||||
| Plakas, van Zuijen, et al., 2013 (2) | 3:4 (3:4) | 10 (13) | Dyslexia versus controls: | Confirmed with standardized testing | — | ||
| IQ (SON-R) | −.60 | ||||||
| Language comprehension (Reynell) | −.74 | ||||||
| Phon Aw (deletion) | −2.37 | ||||||
| vSTM (word span) | −.80 | ||||||
| 3:4 (3:4) | 15 (13) | Unaffected family-risk versus controls: | Confirmed with standardized testing | — | |||
| IQ (SON-R) | −.22 | ||||||
| Language comprehension (Reynell) | .26 | ||||||
| Phon Aw (deletion) | −.52 | ||||||
| vSTM (word span) | .26 | ||||||
| Plakas, van Zuijen, et al., 2013 (2) | 41 months | 15 (13) | Unaffected family-risk versus controls: | Confirmed with standardized testing | — | ||
| Grammar (expressive syntax) | .17 | ||||||
| Regtvoort, van Leeuwen, et al., 2006 (2) | 5:6 (5) | 11 (12) | Dyslexia versus controls: | Confirmed with standardized testing | — | ||
| Nonword reading (1-min nonword reading test) | −.99 | ||||||
| Spelling (spelling test) | −1.84 | ||||||
| Word reading (1-min reading test) | −2.72 | ||||||
| 5:6 (5) | 15 (12) | Unaffected family-risk versus controls: | Confirmed with standardized testing | — | |||
| Nonword reading (1-min nonword reading test) | −.72 | ||||||
| Spelling (spelling test) | −.29 | ||||||
| Word reading (1 min reading test) | −.16 | ||||||
| Scarborough, 1990 (7) | Dyslexia versus controls: | Confirmed with standardized testing | Matched on SES | ||||
| 30 months | 20 (20) | Articulatory accuracy (consonant errors) | −1.01 | ||||
| Vocabulary knowledge (BNT) | −.50 | ||||||
| Vocabulary knowledge (PPVT) | −.86 | ||||||
| 2nd grade | IQ (WISC) | −.42 | |||||
| Word reading (WJ reading cluster) | −2.99 | ||||||
| Unaffected family-risk versus controls: | Confirmed with standardized testing | Matched on SES | |||||
| 30 months | 12 (20) | Articulatory accuracy (consonant errors) | −.08 | ||||
| Vocabulary knowledge (PPVT) | −.20 | ||||||
| Vocabulary knowledge (BNT) | −.32 | ||||||
| 2nd grade | IQ (WISC) | .28 | |||||
| Word reading (WJ reading cluster) | −.03 | ||||||
| Scarborough, 1991a (7) | 2nd grade | 35 (44) | Only prevalence coded since means and SDs on single tests were not reported. | 65%/.05% | Confirmed with standardized testing | Matched on SES | |
| Smith, 2009 (8) | 8:9 (8:9) | 10 (7) | Dyslexia versus controls: | 58% | Confirmed with standardized testing | Mothers in high-risk sample had significantly lower education level than mothers in control sample | |
| Maternal education | −1.20 | ||||||
| Nonword reading (WJ word attack) | −.78 | ||||||
| Word reading (WRMT-R word ID) | −2.56 | ||||||
| Reading comprehension | −2.30 | ||||||
| 8:9 (8:9) | 10 (7) | Unaffected family-risk versus controls: | −1.83 | Confirmed with standardized testing | Mothers in high-risk sample had significantly lower education level than mothers in control sample | ||
| Maternal education | .75 | ||||||
| Nonword reading (WJ word attack) | .30 | ||||||
| Word reading (WRMT-R word ID) | .36 | ||||||
| Reading comprehension | |||||||
| Smith, Roberts, Locke, & Tozer, 2010 (8) | 8–19 months | 6 (5) | Unaffected family-risk versus controls: | Confirmed with standardized testing | Mothers in high-risk sample had significantly lower education level | ||
| Articulatory accuracy (syllable index score) | −.71 | ||||||
| Language comprehension (general conceptual ability) | −.88 | ||||||
| Smith, Smith, et al., 2008 (8) | Dyslexia versus controls: | Confirmed with standardized testing | Mothers in high-risk sample had significantly lower education level | ||||
| Age 2–3 | 9 (9) | Vocabulary knowledge (DAS expressive vocabulary) | −.71 | ||||
| IQ (Bayley comprehension) | −.60 | ||||||
| Vocabulary knowledge (DAS language comprehension) | −.95 | ||||||
| vSTM (DAS digit recall) | −.79 | ||||||
| Nonword reading (WRMT word attack) | −2.96 | ||||||
| Reading comprehension (GORT | −1.17 | ||||||
| Grade school | Word reading (WRMT word ID) | −5.46 | |||||
| Unaffected family-risk versus controls: | Confirmed with standardized testing | Mothers in high-risk sample had significantly lower education level | |||||
| Age 2–3 | 9 (9) | Vocabulary knowledge (DAS expressive vocabulary) | −.88 | ||||
| IQ (Bayley comprehension) | .19 | ||||||
| Vocabulary knowledge (DAS language comprehension) | −1.08 | ||||||
| vSTM (DAS digit recall) | −.58 | ||||||
| Grade school | Nonword reading (WRMT word attack) | −.42 | |||||
| Reading comprehension (GORT | −.19 | ||||||
| Word reading (WRMT word ID) | −.69 | ||||||
| Snowling et al., 2003 (5) | 3:9 (3:9) | 37 (25) | Dyslexia versus controls: | 66%/16% | Confirmed with standardized testing | Middle-class volunteer sample | |
| Articulatory accuracy (Edinburgh articulation test) | −.14 | ||||||
| Rhyme awareness (nursery rhymes) | −1.20 | ||||||
| IQ (Draw A Man [Harris, 1963]) | −.45 | ||||||
| Vocabulary knowledge (BPVS) | −1.40 | ||||||
| Letter knowledge (identify 26 letters by name and sound) | −1.06 | ||||||
| Phon Aw (nursery rhyme knowledge) | −1.21 | ||||||
| Phon memory (CN Rep) | −.99 | ||||||
| 3:9 (3:9) | 19 (25) | Unaffected family-risk versus controls: | Confirmed with standardized testing | Middle-class volunteer sample | |||
| Articulatory accuracy (Edinburgh articulation test) | .20 | ||||||
| Rhyme awareness (nursery rhymes) | −.54 | ||||||
| IQ (Draw a man (Harris, 1963) | .62 | ||||||
| Language comprehension (BPVS) | −.40 | ||||||
| Vocabulary knowledge (BPVS) | −.40 | ||||||
| Letter knowledge (identify 26 letters by name and sound) | −.48 | ||||||
| Phon Aw (nursery rhyme knowledge) | −.54 | ||||||
| Phon memory (CN Rep) | −.53 | ||||||
| 8 years | 37 (25) | Dyslexia versus controls: | Confirmed with standardized testing | Middle-class volunteer sample | |||
| IQ (composite BAS Matrices and BAS Recall of Designs) | −.65 | ||||||
| Vocabulary knowledge (WOLD listening comprehension) | −1.66 | ||||||
| Nonword reading (Graded Nonword Reading Test [Snowling et al. 1996]) | −2.36 | ||||||
| Phon Aw (Phoneme deletion) | −1.58 | ||||||
| Phon memory (nonword repetition three and four syllable) | −1.48 | ||||||
| Reading comprehension (WORD reading comprehension) | −3.04 | ||||||
| Spelling (WORD spelling) | −2.80 | ||||||
| Word reading (WORD reading) | −2.79 | ||||||
| Rhyme awareness (rhyme oddity) | −1.30 | ||||||
| 8 years | 19 (25) | Unaffected family-risk versus controls: | Confirmed with standardized testing | Middle-class volunteer sample | |||
| IQ (composite BAS Matrices and BAS Recall of Designs) | −.29 | ||||||
| Vocabulary knowledge (WOLD listening comprehension) | −.47 | ||||||
| Nonword reading (Graded Nonword Reading Test (Snowling et al. 1996)) | −1.29 | ||||||
| Phon Aw (phoneme deletion) | −.80 | ||||||
| Phon memory (nonword repetition three and four syllable) | −.52 | ||||||
| Reading comprehension (WORD reading comprehension) | −1.02 | ||||||
| Spelling (WORD spelling) | −.25 | ||||||
| Word reading (WORD reading) | −.60 | ||||||
| Rhyme awareness (rhyme oddity) | −.24 | ||||||
| Snowling, Muter, & Carroll, 2007 (5) | 12–13 | 21 (17) | Dyslexia versus controls: | Confirmed with standardized testing | Middle-class volunteer sample | ||
| Vocabulary knowledge (WASI vocabulary) | −1.75 | ||||||
| Nonword reading (from Griffiths & Snowling, 2001) | −1.82 | ||||||
| Phon Aw (Phoneme deletion) | −1.36 | ||||||
| Phon memory (CN Rep) | −1.16 | ||||||
| Reading comprehension (NARA) | −1.05 | ||||||
| Spelling (WORD spelling) | −2.75 | ||||||
| Word reading (exception word reading) | −1.93 | ||||||
| 12–13 | 29 (17) | Unaffected family-risk versus controls: | −.43 | Confirmed with standardized testing | Middle-class volunteer sample | ||
| Vocabulary knowledge (WASI vocabulary) Nonword reading (from Griffiths & Snowling, 2001) | −.37 | ||||||
| Phon Aw (phoneme deletion) | −.26 | ||||||
| Phon memory (CN Rep) | −.21 | ||||||
| Reading comprehension (NARA) | −.10 | ||||||
| Spelling (WORD spelling) | −.89 | ||||||
| Word reading (exception word reading) | −.80 | ||||||
| Torppa, Lyytinen, Erskine, et al., 2010 (3) | 5 years | 37 (84) | Dyslexia versus controls: | Confirmed with testing | Mothers of the children in the dyslexia affected group had on average a lower education level than children in the two other groups | ||
| Vocabulary knowledge (PPVT) | −.65 | ||||||
| Letter knowledge (nonstandardized task) | −1.35 | ||||||
| Phon Aw (phonological sensitivity [NEPSY]) | −.76 | ||||||
| RAN (Denckla & Rudel, 1976) | −1.06 | ||||||
| Grammar (inflectional morphology adverb and past tense) | −.79 | ||||||
| 5 years | 68 (84) | Unaffected family-risk versus controls: | |||||
| Vocabulary knowledge (PPVT) | −.32 | ||||||
| Letter knowledge (nonstandardized task) | −.33 | ||||||
| Phon Aw (phonological sensitivity [NEPSY]) | −.28 | ||||||
| RAN (Denckla & Rudel, 1976) | −.25 | ||||||
| Grammar (inflectional morphology adverb and past tense) | −.37 | ||||||
| Second grade | 37 (84) | Dyslexia versus controls: | 35%/10% | Confirmed with testing | Mothers of the children in the dyslexia affected group had on average a lower education level than children in the two other groups | ||
| Nonword reading (nonword reading) | −1.65 | ||||||
| Spelling (spelling words and nonwords) | −1.71 | ||||||
| Word reading (word reading accuracy in meaningful text) | −1.38 | ||||||
| Second grade | 68 (84) | Unaffected family-risk versus controls: | Confirmed with testing | Mothers of the children in the dyslexia affected group had on average a lower education level than children in the two other groups | |||
| Nonword reading (nonword reading) | −.17 | ||||||
| Spelling (spelling words and nonwords) | −.16 | ||||||
| Word reading (word reading accuracy in meaningful text) | −.04 | ||||||
| van Bergen, de Jong, Plakas, et al., 2012 (2) | 48 (48) | 42 (66) | Dyslexia versus controls: | 30%/.03% | Confirmed with testing | Children in at-risk group had parents (both mothers and fathers) with significantly lower education than in the control sample | |
| IQ (SON-R nonverbal IQ test) | −.53 | ||||||
| Unaffected family-risk versus controls: | |||||||
| IQ (SON-R nonverbal IQ test) | −.03 | ||||||
| 98 (96) | 42 (66) | Dyslexia versus controls: | Confirmed with testing | Children in at-risk group had parents (both mothers and fathers) with significantly lower education than in the control sample | |||
| Nonword reading (nonword reading accuracy [de Jong & Wolters, 2002]) | −2.06 | ||||||
| Phon Aw (phoneme deletion) | −1.84 | ||||||
| RAN (digits and colors) | −.98 | ||||||
| Spelling (write down words presented in a sentence) | −1.74 | ||||||
| Word reading (word reading accuracy test) | −2.42 | ||||||
| 98 (96) | 99 (66) | Unaffected family-risk versus controls: | Confirmed with testing | Children in at-risk group had parents (both mothers and fathers) with significantly lower education than in the control sample | |||
| Nonword reading (nonword reading accuracy [de Jong & Wolters, 2002]) | −.56 | ||||||
| Phon Aw (phoneme deletion) | −.66 | ||||||
| RAN (digits and colors) | −.15 | ||||||
| Spelling (write down words presented in a sentence) | −.37 | ||||||
| Word reading (word reading accuracy test) | −.64 | ||||||
| van Bergen, de Jong, Regtvoort et al. 2011 (2) | 70.4 (70) | 22 (12) | Dyslexia versus controls: | 32% | Confirmed with testing | Children in at-risk group had parents (both mothers and fathers) with significantly lower education than in the control sample | |
| Letter knowledge (receptive letter knowledge task) | −1.42 | ||||||
| Phon Aw (phoneme blending and segmentation) | −.10 | ||||||
| RAN (colors and object) | −1.39 | ||||||
| Word reading (3 min reading test) | −3.13 | ||||||
| 70.6 (70) | 45 (12) | Unaffected family-risk versus controls: | Confirmed with testing | Children in at-risk group had parents (both mothers and fathers) with significantly lower education than in the control sample | |||
| Letter knowledge (receptive letter knowledge task) | −.54 | ||||||
| Phon Aw (phoneme blending and segmentation) | .02 | ||||||
| RAN (colors and object) | −.64 | ||||||
| Word reading (3 min reading test) | −2.16 | ||||||
| Dyslexia versus controls: | |||||||
| Grade 1 | 22 (12) | IQ (Raven) | −.37 | ||||
| Language comprehension (similar to PPVT) | −.11 | ||||||
| Grade 5 | 22 (12) | Nonword reading (2 min pseudoword test) | −4.60 | ||||
| Grade 1 | 45 (12) | Unaffected family-risk versus controls: | |||||
| IQ (Raven) | −.22 | ||||||
| Grade 5 | 45 (12) | Language comprehension (similar to PPVT) | −.09 | ||||
| Nonword reading (2 min pseudoword test) | −2.92 | ||||||
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