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
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
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