Table 2 Summary of linkage findings in dyslexia.
Locus | Number of families (individuals, sib pairs), country | Linkage evidence | Linkage evidence with components of the phenotype | Study design | References |
---|---|---|---|---|---|
DYX1 | 9 multiplex families (84 individuals), USA | LOD score 3.20 | Reading | Categorical | Smith et al46 |
6 multiplex families (94 individuals), USA | LOD score 3.15 | Single‐word reading | Categorical | Grigorenko et al47 | |
7 multiplex families (67 individuals), Germany | LOD score 1.78 | Spelling | Categorical | Schulte‐Körne et al48 | |
90 families (611 individuals), USA | LOD score 2.34 | Single‐word reading | Categorical | Chapman et al49 | |
DYX2 | 19 multiplex families (358 individuals*, 50 dizygotic twin‐pair), USA | p Values between 0.009–0.04 | Dyslexia | QTL | Cardon et al50 |
82 families (181 sib pairs), UK | p Values between 0.0004–0.038 | Orthographic and phonological processes | QTL | Fisher et al51 | |
79 families (126 sib pairs), USA | LOD scores between 2.42 and 3.10 | Orthographic and phonological processes | QTL | Gayan et al52 | |
89 families (195 sib pairs)†, UK | p Values between 0.00001–0.042 | Phonological decoding | QTL | Fisher et al53 | |
119 families (180 sib pairs)‡, USA | p Values between 0.002–0.006 | Phonological decoding | |||
104 families (392 individuals)‡, USA | p Values between 0.0005–0.05 | Orthographic and phonological processes | QTL | Kaplan et al54 | |
8 multiplex families (176 individuals)§ | LOD scores of 1.52 and 2.56 | Single‐word reading, phoneme awareness | Categorical | Grigorenko et al55 | |
DYX3 | 1 multiplex family (36 individuals), Norway | LOD score 4.32 | Dyslexia | Categorical | Fagerheim et al56 |
89 families (195 sib pairs), UK | p Value <0.001 | Orthographic choice | QTL | Fisher et al53 | |
119 families (180 sib pairs), USA | p Value of 0.001 | Phonological awareness | QTL | ||
96 families (877 individuals), Canada | LOD scores of 1.13 and 3.82 | Phonological coding, spelling | QTL and categorical | Petryshen et al57 | |
11 multiplex families (97 individuals), Finland | LOD score 3.01 | Dyslexia | Categarical | Kaminen et al58 | |
DYX4 | 96 families (877 individuals), Canada | LOD scores of 2.08 and 3.34 | Phonological coding, spelling | QTL and categorical | Petryshen et al59 |
DYX5 | 1 multiplex family (74 individuals), Finland | LOD score 3.84 | Dyslexia | Categorical | Nopola‐Hemmi et al60 |
DYX6 | 89 families (195 sib pairs), UK | p Value <0.001 | Single‐word reading | QTL | Fisher et al53 |
119 families (180 sib pairs), USA | p Value <0.001 | Single‐word reading | QTL | ||
84 families (143 sib pairs), UK | p Value <0.001 | Phoneme awareness | QTL | ||
DYX7 | 100 families (914 individuals), Canada | p Value <0.001 | Dyslexia | Categorical | Hsiung et al61 |
DYX8 | 9 families, USA | LOD score of 1.95 and 2.33 | Dyslexia | QTL | Rabin et al62 |
8 multiplex families (165 individuals), USA | LOD scores of 3.00 and 2.30 | Single‐word reading, phonological decoding | Categorical | Grigorenko et al63 | |
100 families (914 individuals), Canada | LOD scores of 4.01 and 1.65 | Spelling, phonological coding | QTL and categorical | Tzenova et al64 | |
DYX9 | 1 multiplex family (29 individuals), Netherlands | LOD score 3.68 | Dyslexia | Categorical | de Kovel et al65 |
89 families (195 sib pairs), UK | p Value of 0.001 | Single‐word reading | QTL | Fisher et al53 |
LOD, logarithm of the odds; QTL, quantitative trait loci.
*Including 18 families with linkage evidence at DYX2 previously reported by Smith et al.46
†Including 82 families with linkage evidence at DYX2 previously reported by Fisher et al.51
‡Including 39 families with linkage evidence at DYX2 previously reported by Cardon et al50 and 70 families with linkage evidence at DYX2 previously reported by Gayan et al.52
§Including 8 families with linkage evidence at DYX2 previously reported by Grigorenko et al.47,55