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Identification of a Susceptibility Locus for Severe Adolescent Idiopathic Scoliosis on Chromosome 17q24.3

  • Atsushi Miyake,

    Affiliations Laboratory for Bone and Joint Diseases, RIKEN Center for Integrative Medical Science, Tokyo, Japan, Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan

  • Ikuyo Kou,

    Affiliation Laboratory for Bone and Joint Diseases, RIKEN Center for Integrative Medical Science, Tokyo, Japan

  • Yohei Takahashi,

    Affiliations Laboratory for Bone and Joint Diseases, RIKEN Center for Integrative Medical Science, Tokyo, Japan, Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan

  • Todd A. Johnson,

    Affiliation Laboratory for Medical Science Mathematics, RIKEN Center for Integrative Medical Science, Yokohama, Japan

  • Yoji Ogura,

    Affiliations Laboratory for Bone and Joint Diseases, RIKEN Center for Integrative Medical Science, Tokyo, Japan, Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan

  • Jin Dai,

    Affiliation Department of Orthopaedics, The Center of Diagnosis and Treatment for Joint Disease, Drum Tower Hospital Affiliated to Medical School of Nanjing University, Nanjing, China

  • Xusheng Qiu,

    Affiliation Department of Spine Surgery, Drum Tower Hospital Affiliated to Medical School of Nanjing University, Nanjing, China

  • Atsushi Takahashi,

    Affiliation Laboratory for Statistical Analysis, RIKEN Center for Integrative Medical Science, Tokyo, Japan

  • Hua Jiang,

    Affiliation Department of Spine Surgery, Drum Tower Hospital Affiliated to Medical School of Nanjing University, Nanjing, China

  • Huang Yan,

    Affiliation Department of Spine Surgery, Drum Tower Hospital Affiliated to Medical School of Nanjing University, Nanjing, China

  • Katsuki Kono,

    Affiliation Scoliosis Center, Saiseikai Central Hospital, Tokyo, Japan

  • Noriaki Kawakami,

    Affiliation Department of Orthopaedic Surgery, Meijo Hospital, Nagoya, Japan

  • Koki Uno,

    Affiliation Department of Orthopaedic Surgery, National Hospital Organization, Kobe Medical Center, Kobe, Japan

  • Manabu Ito,

    Affiliation Department of Advanced Medicine for Spine and Spinal Cord Disorders, Hokkaido University Graduate School of Medicine, Sapporo, Japan

  • Shohei Minami,

    Affiliation Department of Orthopaedic Surgery, Seirei Sakura Citizen Hospital, Sakura, Japan

  • Haruhisa Yanagida,

    Affiliation Department of Orthopaedic Surgery, Fukuoka Children's Hospital, Fukuoka, Japan

  • Hiroshi Taneichi,

    Affiliation Department of Orthopaedic Surgery, Dokkyo Medical University School of Medicine, Mibu, Japan

  • Naoya Hosono,

    Affiliation Laboratory for Genotyping Development, RIKEN Center for Integrative Medical Science, Yokohama, Japan

  • Taichi Tsuji,

    Affiliation Department of Orthopaedic Surgery, Meijo Hospital, Nagoya, Japan

  • Teppei Suzuki,

    Affiliation Department of Orthopaedic Surgery, National Hospital Organization, Kobe Medical Center, Kobe, Japan

  • Hideki Sudo,

    Affiliation Department of Advanced Medicine for Spine and Spinal Cord Disorders, Hokkaido University Graduate School of Medicine, Sapporo, Japan

  • Toshiaki Kotani,

    Affiliation Department of Orthopaedic Surgery, Seirei Sakura Citizen Hospital, Sakura, Japan

  • Ikuho Yonezawa,

    Affiliation Department of Orthopaedic Surgery, Juntendo University School of Medicine, Tokyo, Japan

  • Michiaki Kubo,

    Affiliation Laboratory for Genotyping Development, RIKEN Center for Integrative Medical Science, Yokohama, Japan

  • Tatsuhiko Tsunoda,

    Affiliation Laboratory for Medical Science Mathematics, RIKEN Center for Integrative Medical Science, Yokohama, Japan

  • Kota Watanabe,

    Affiliation Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan

  • Kazuhiro Chiba,

    Affiliation Department of Orthopaedic Surgery, Kitasato University Kitasato Institute Hospital, Tokyo, Japan

  • Yoshiaki Toyama,

    Affiliation Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan

  • Yong Qiu,

    Affiliation Department of Spine Surgery, Drum Tower Hospital Affiliated to Medical School of Nanjing University, Nanjing, China

  • Morio Matsumoto ,

    sikegawa@ims.u-tokyo.ac.jp (SI); morio@a5.keio.jp (MM)

    Affiliation Department of Orthopaedic Surgery, School of Medicine, Keio University, Tokyo, Japan

  •  [ ... ],
  • Shiro Ikegawa

    sikegawa@ims.u-tokyo.ac.jp (SI); morio@a5.keio.jp (MM)

    Affiliation Laboratory for Bone and Joint Diseases, RIKEN Center for Integrative Medical Science, Tokyo, Japan

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Abstract

Adolescent idiopathic scoliosis (AIS) is the most common spinal deformity, affecting around 2% of adolescents worldwide. Genetic factors play an important role in its etiology. Using a genome-wide association study (GWAS), we recently identified novel AIS susceptibility loci on chromosomes 10q24.31 and 6q24.1. To identify more AIS susceptibility loci relating to its severity and progression, we performed GWAS by limiting the case subjects to those with severe AIS. Through a two-stage association study using a total of ∼12,000 Japanese subjects, we identified a common variant, rs12946942 that showed a significant association with severe AIS in the recessive model (P = 4.00×10−8, odds ratio [OR] = 2.05). Its association was replicated in a Chinese population (combined P = 6.43×10−12, OR = 2.21). rs12946942 is on chromosome 17q24.3 near the genes SOX9 and KCNJ2, which when mutated cause scoliosis phenotypes. Our findings will offer new insight into the etiology and progression of AIS.

Introduction

Adolescent idiopathic scoliosis (AIS) is the most common structural deformity of the spine, occurring in 2–3% of healthy children from the age of 10 to skeletal maturity worldwide [1]. A Japanese study showed that the incidence of scoliosis of more than 15 degrees increases linearly with age from 10 (0.07% in boys, 0.44% in girls) to 14 (0.25% in boys, 1.77% in girls), and that most of these cases are AIS [2].

AIS is a multi-factorial disorder, with genetic factors playing an important role in its etiology [3]. Population studies have shown that its familial incidence is higher than that in general populations [4], while twin studies have consistently shown higher concordance in monozygotic compared with dizygotic twins. For example, a meta-analysis of several twin studies revealed 73% monozygotic and 36% dizygotic twin concordance [5]. Using the Danish Twin Registry, Andersen et al. observed 25% proband-wise concordance in monozygotic twins (six of 44 concordant) compared with 0% concordance in dizygotic twins (0 of 91), with an overall prevalence of approximately 1% [6].

Several genetic studies regarding AIS susceptibility have previously been reported. Although genome-wide linkage analyses have revealed some AIS susceptibility loci [7][16], only CHD7 has been identified as a susceptibility gene [13]. Genetic association studies of AIS, however, have identified several predisposition genes. Single nucleotide polymorphisms (SNPs) in ESR1, ESR2, MATN1, MTNR1B, and TPH1 genes are reported to be associated with AIS susceptibility [17][21]. Recently, we used genome-wide association study (GWAS) to identify novel AIS susceptibility locus on chromosomes 10q24.31 near the LBX1 gene [22] and 6q24.1 in the GPR126 gene [23].

We used a common-control design [24], [25] in our previous GWAS. However, because undiagnosed general populations or patients with unrelated diseases are used as controls in this design, there is a potential loss of power associated with the inability to exclude latent diagnoses of the disease. One way of overcoming this is to adopt a more stringent case definition; for example, one based on early age of onset or the identification of a more severe disease phenotype [26]. Severe cases are presumed to have a high prevalence of susceptibility alleles for that disease and lower phenotypic heterogeneity, and will hence improve the study power by enriching for specific disease-predisposing alleles. In addition, it is clinically important to consider the factors that influence the progression of scoliosis, as the treatment of AIS patients depends on its severity and possibility of progression. Both of these factors have a genetic component [27], [28]: the Danish meta-analysis twin study showed a significant correlation with curve severity in monozygous but not dizygous twins [5], while SNPs in ESR1, ESR2, MATN1 and IGF1 genes are associated with AIS severity [17][19], [29]. Studies into severe AIS may clarify the factors that influence AIS progression.

In the current study, we performed GWAS by including in our case group only severely affected AIS subjects with a Cobb's angle above 40°. We have identified a novel susceptibility locus for severe AIS on chromosome 17q24.3 that showed genome-wide significance and replication of association in different ethnic populations.

Materials and Methods

Subjects

We defined Cobb's angle for severe AIS was above 40°. Cobb's angles were obtained at the time the patient was recruited in this study. A written informed consent was obtained from all subjects participating in the study. The study was approved by the institutional review boards of RIKEN and participating institutions. The subjects for the GWAS were all Japanese females; 554 with severe AIS (aged 10–39) and 1,474 control subjects (aged 7–96) were recruited as previously described [22]. For the Japanese replication study, we recruited an independent set of a case-control subjects consisting of 268 severe AIS (aged 10–59) and 9,823 controls (aged 20–96) in the same way. For examining the relation between the genotype of the SNPs identified by the case-control association study and the AIS severity (Cobb angle) in Japanese, we collected the data of 1,767 AIS subjects used for the previous GWAS and replication studies who had AIS with a Cobb angle of 10° or greater. All were Japanese female. For the replication study in Chinese, we recruited 571 females with severe AIS (aged 10–19) and 326 female controls (aged 25–83) living in and around Nanjing city, China. All were self-reported Han Chinese.

Genotyping of SNPs and Quality Control

Genomic DNA was extracted from the peripheral blood leukocytes of severe AIS and control subjects using standard protocols. In the GWAS, we genotyped case subjects using the Illumina Human610 Genotyping BeadChip and control subjects with the Illumina HumanHap550v3 Genotyping BeadChip. SNPs common to both platforms were then combined and analyzed as previously described [30]. Inadequate SNPs and subjects were checked and excluded as previously described [22]. In the Japanese replication study, the case subjects were genotyped using the PCR-based Invader assay [31] and controls were genotyped using Illumina HumanHap550v3 Genotyping BeadChip. In the Chinese replication study, all subjects were genotyped using the PCR-based Invader assay as described above.

Statistical Analysis

The association between the SNPs was examined by x2 test for three models (allele model, recessive model and dominant model) and minimum P values in the three models were evaluated. In the same way, incidence of severe AIS, and the Hardy–Weinberg equilibrium (HWE) of the genotypes were examined by x2 test. Data of GWAS and Japanese replication study were combined by addition, and data of total Japanese studies and Chinese study were combined using the Mantel-Haenszel method. The Breslow-Day statistic was used to test homogeneity of the common odds ratio. The associations between the SNP genotypes and the Cobb angle of AIS subjects were evaluated using the Kruskal-Wallis and Mann-Whitney U tests. Imputation was performed using MACH version 1.0.16.c. and Minimac software with reference haplotypes from the 1000 Genomes Project June 2011 EAS population as described elsewhere [23]. In the analysis, pairwise r2 values were calculated using the R Bioconductor package snpMatrix (version 1.16.2), and the LD map was created using in-house programs. We performed association analysis of imputed data using the single.snp.tests function in the R package snpStats version 1.3.4 after converting Minimac output to the uncertain genotype data format for snpStats. Regional association plots were generated using R statistical environment version 2.13.0.

Results

After stringent quality control of the subjects and SNPs, we examined the association of 455,121 SNPs with severe AIS using the χ2 test for three models (allele model, recessive model and dominant model). No SNP reached the GWAS significance threshold (P<5×10−8) at this stage (Figure S1).

Then, we selected 27 SNPs (Table S1) according to the following criteria: 1) a minimum P value in the three models <1×10−4; 2) a minor allele frequency ≥0.1. SNPs in strong linkage disequilibrium (LD) with a correlation coefficient (r2) of 0.8 with other SNPs were excluded from analysis. We checked their association using an independent set of Japanese female case-control subjects and combined all Japanese data.

Six SNPs showed association of genome-wide significance level (P<5×10−8) (Table 1). Five of them were in the known loci of AIS susceptibility that we previously reported; three SNPs (rs11190870, rs625039 and rs11598564) were close to LBX1 on chromosome 10q24.31 [22] and two SNPs (rs6570507 and rs9496346) were on chromosome 6q24.1 in the GPR126 gene [23]. In addition, rs12946942 on chromosome 17q24.3 showed significant association in the recessive model (P = 4.00×10−8, odds ratio [OR]  = 2.05). We further examined the relation between the rs12946942 genotypes and the AIS severity (Cobb's angle) using a total of 1,767 AIS cases. rs12946942 showed significant association (P = 3.02×10−2; by the Kruskal-Wallis test).

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Table 1. Association of the 27 SNPs in the two-stage association study for AIS in Japanese.

https://doi.org/10.1371/journal.pone.0072802.t001

We performed a replication study for rs12946942 in a Chinese case-control population. The association of rs12946942 was significant in the Chinese population for all three models. Combined P values from the Mantel-Haenszel method for the Japanese and Chinese studies in the recessive model showed genome-wide significance (P = 6.43×10−12) (Table 2).

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Table 2. Association of rs12946942 with severe AIS in Japanese and Chinese populations.

https://doi.org/10.1371/journal.pone.0072802.t002

rs12946942 defined a 130-kb LD block within an approximately 2-Mb region on chromosome 17 (Figure 1). No RefSeq genes have been mapped in this LD block. Twenty common SNPs in the LD block were genotyped in the GWAS, the most significant of which was rs12946942 (Figure 1).

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Figure 1. Linkage disequilibrium (LD) map and P-value plot of the severe adolescent idiopathic scoliosis susceptibility locus at chromosome 17q24.3.

Top panel: The association results shown as – log10 of minimum P values in allele, recessive and dominant models and a focus view of the 130-kb LD block including rs12946942. All SNPs are analyzed in GWAS. Two vertical lines in this graph indicate the range of the LD block. rs12946942 is boxed. Middle panel: The ∼2 Mb LD map (D') around rs12946942 is shown using loci with MAF >0.10 from Phase II HapMap (release 24) JPT individuals. LD score: (dark red) LOD >2, D' = 1; (light red) LOD >2, D'<1; (blue) LOD <2, D' = 1; (white) LOD <2, D'<1. Bottom panel: The position of rs12946942 and the two candidate genes (KCNJ2 and SOX9) on chromosome (Chr.) 17.

https://doi.org/10.1371/journal.pone.0072802.g001

To further characterize the chromosome 17q24.3 locus, we imputed genotypes of additional SNPs in the locus using 1000 Genomes Project's East Asian population samples' (EAS) reference haplotypes and tested their association with AIS. SNPs rs12946942 and rs12941471 yielded the strongest evidence for association (Figure S2A), which were in complete LD (r2 = 1) with each other. After conditioning on the top SNP (rs12946942), there was no secondary association signal for AIS within the region (Figure S2B).

Discussion

The region defined by rs12946942 was a gene desert. The closest genes include SOX9 and KCNJ2 [32]. SOX9 (MIM 608160) is a promising candidate gene for AIS as it encodes a transcription factor involved in chondrogenesis [33]. SOX9 mutations cause campomelic dysplasia (MIM 114290), a skeletal dysplasia characterized by bowed, long bones, small scapula, tracheobronchial narrowing, sex reversal and kyphoscoliosis [34]. Very long-range cis-regulatory elements controlling tissue-specific SOX9 expression have been previously reported [35], [36]. The LD block containing rs12946942 has recently been defined as a susceptibility locus of prostate cancer in European Caucasians [37]. The block contains six enhancer elements, of which the E1 enhancer forms a long-range chromatin loop to SOX9 in a prostate cancer cell line. Two SNPs within the E1 enhancer were shown by in vitro reporter assays to direct allele-specific gene expression. We hypothesize that variants in this region may likewise participate in scoliosis pathogenesis by controlling scoliosis-related tissue-specific expression of SOX9 or other genes.

KCNJ2 (MIM 600681) is another promising candidate gene for AIS. It encodes the inward-rectifying potassium channel Kir2.1, which is a component of the inward rectifier current IK1. IK1 provides a repolarizing current during the most terminal phase of repolarization and is the primary conductance that controls the diastolic membrane potential [38]. KCNJ2 mutations lead to a cardiodysrhythmic type of periodic paralysis known as Andersen-Tawil syndrome (ATS; MIM 170390) [39], which is characterized by ventricular arrhythmias, periodic paralysis, facial and skeletal dysmorphism including hypertelorism, small mandible, cleft palate, syndactyly, clinodactyly, and scoliosis [38], [39]. Furthermore, the 17q24.2-q24.3 micro-deletion syndrome whose deletion area includes KCNJ2 and rs12946942 showed skeletal malformations similar to the ATS phenotype including progressive scoliosis [40]. Interestingly, a similar micro-deletion syndrome including KCNJ2, but not rs12946942, was not associated with a scoliosis phenotype [41].

Thus, through a Japanese GWAS followed by replication studies in Japanese and Chinese populations, we identified a susceptibility locus for severe AIS on chromosome 17q24.3 that showed genome-wide significance. This region contains a few promising candidate genes that may be associated with the disease. Further studies are now necessary to identify the causal gene and its variant in the locus.

Supporting Information

Figure S1.

Manhattan plot showing the P values from genome-wide association study (minimum P value in allele, recessive and dominant models). The horizontal line represents the genome-wide significance threshold (P = 5×10−8).

https://doi.org/10.1371/journal.pone.0072802.s001

(TIF)

Figure S2.

Regional association plots and recombination rates of AIS susceptibility locus on chromosome 17q24.3. The chromosome position (NCBI Build 37) of SNPs against −log10 [P value] from a logistic regression analysis is shown. (A) Unconditioned analysis. The SNP with highest association signal (rs12946942) is represented as a purple diamond. Imputed (circles) and genotyped SNPs (squares) are colored according the LD (r2) with rs12946942. (B) Conditioned analysis. Red circles are unconditioned and gray circles are conditioned for rs12946942 (gray triangle).

https://doi.org/10.1371/journal.pone.0072802.s002

(TIF)

Table S1.

Association of the 27 SNPs selected from the GWAS.

https://doi.org/10.1371/journal.pone.0072802.s003

(DOC)

Acknowledgments

We thank the individuals who participated in this study. A part of the study is supported by BioBank Japan.

Author Contributions

Conceived and designed the experiments: AM MM SI. Performed the experiments: AM Y. Takahashi JD MK. Analyzed the data: AM IK TAJ AT T. Tsunoda. Contributed reagents/materials/analysis tools: YO XQ HJ H. Yan KK NK KU MI SM H. Yanagida HT NH T. Tsuji TS HS TK IY KW KC Y. Toyama YQ. Wrote the paper: AM SI.

References

  1. 1. Weinstein SL (1999) Natural history. Spine 24: 2592–2600.
  2. 2. Ohtsuka Y, Yamagata M, Arai S, Kitahara H, Minami S (1988) School screening for scoliosis by the Chiba University Medical School screening program. Results of 1.24 million students over an 8-year period. Spine 13: 1251–1257.
  3. 3. Wise CA, Gao X, Shoemaker S, Gordon D, Herring JA (2008) Understanding genetic factors in idiopathic scoliosis, a complex disease of childhood. Curr Genomics 9: 51–59.
  4. 4. Lowe TG, Edgar M, Margulies JY, Miller NH, Raso VJ, et al. (2000) Etiology of idiopathic scoliosis: current trends in research. J Bone Joint Surg Am 82: 1157–1168.
  5. 5. Kesling KL, Reinker KA (1997) Scoliosis in twins. A meta-analysis of the literature and report of six cases. Spine 22: 2009–2014.
  6. 6. Andersen MO, Thomsen K, Kyvik KO (2007) Adolescent idiopathic scoliosis in twins: a population-based survey. Spine 32: 927–930.
  7. 7. Wise CA, Barnes R, Gillum J, Herring JA, Bowcock AM, et al. (2000) Localization of susceptibility to familial idiopathic scoliosis. Spine 25: 2372–2380.
  8. 8. Ocaka L, Zhao C, Reed JA, Ebenezer ND, Brice G, et al. (2008) Assignment of two loci for autosomal dominant adolescent idiopathic scoliosis to chromosomes 9q31.2 and 17q25.3-qtel. J Med Genet 45: 87–92.
  9. 9. Salehi LB, Mangino M, De Serio S, De Cicco D, Capon F, et al. (2002) Assignment of a locus for autosomal dominant idiopathic scoliosis (IS) to human chromosome 17p11. Hum Genet 111: 401–404.
  10. 10. Alden KJ, Marosy B, Nzegwu N, Justice CM, Wilson AF, et al. (2006) Idiopathic scoliosis: identification of candidate regions on chromosome 19p13. Spine 31: 1815–1819.
  11. 11. Chan V, Fong GC, Luk KD, Yip B, Lee MK, et al. (2002) A genetic locus for adolescent idiopathic scoliosis linked to chromosome 19p13.3. Am J Hum Genet 71: 401–406.
  12. 12. Justice CM, Miller NH, Marosy B, Zhang J, Wilson AF (2003) Familial idiopathic scoliosis: evidence of an X-linked susceptibility locus. Spine 28: 589–594.
  13. 13. Gao X, Gordon D, Zhang D, Browne R, Helms C, et al. (2007) CHD7 gene polymorphisms are associated with susceptibility to idiopathic scoliosis. Am J Hum Genet 80: 957–965.
  14. 14. Raggio CL, Giampietro PF, Dobrin S, Zhao C, Dorshorst D, et al. (2009) A novel locus for adolescent idiopathic scoliosis on chromosome12p. J Orthop Res 27: 1366–1372.
  15. 15. Gurnett CA, Alaee F, Bowcock A, Kruse L, Lenke LG, et al. (2009) Genetic linkage localizes an adolescent idiopathic scoliosis and pectus excavatum gene to chromosome 18q. Spine 34: E94–E100.
  16. 16. Miller NH, Justice CM, Marosy B, Doheny KF, Pugh E, et al. (2005) Identification of candidate regions for familial idiopathic scoliosis. Spine 30: 1181–1187.
  17. 17. Wu J, Qiu Y, Zhang L, Sun Q, Qiu X, et al. (2006) Association of estrogen receptor gene polymorphisms with susceptibility to adolescent idiopathic scoliosis. Spine 31: 1131–1136.
  18. 18. Zhang HQ, Lu SJ, Tang MX, Chen LQ, Liu SH, et al. (2009) Association of estrogen receptor beta gene polymorphisms with susceptibility to adolescent idiopathic scoliosis. Spine 34: 760–764.
  19. 19. Chen Z, Tang NL, Cao X, Qiao D, Yi L, et al. (2009) Promoter polymorphism of matrilin-1 gene predisposes to adolescent idiopathic scoliosis in a Chinese population. Eur J Hum Genet 17: 525–532.
  20. 20. Qiu XS, Tang NL, Yeung HY, Lee KM, Hung VW, et al. (2007) Melatonin receptor 1B (MTNR1B) gene polymorphism is associated with the occurrence of adolescent idiopathic scoliosis. Spine 32: 1748–1753.
  21. 21. Wang H, Wu Z, Zhuang Q, Fei Q, Zhang J, et al. (2008) Association study of tryptophan hydroxylase 1 and arylalkylamine n-acetyltransferase polymorphisms with adolescent idiopathic scoliosis in Han Chinese. Spine 33: 2199–2203.
  22. 22. Takahashi Y, Kou I, Takahashi A, Johnson TA, Kono K, et al. (2011) A genome-wide association study identifies common variants near LBX1 associated with adolescent idiopathic scoliosis. Nat Genet 43: 1237–1240.
  23. 23. Kou I, Takahashi Y, Johnson TA, Takahashi A, Guo L, et al. (2013) Genetic variants in GPR126 are associated with adolescent idiopathic scoliosis. Nat Genet 45: 676–679.
  24. 24. Ozaki K, Ohnishi Y, Iida A, Sekine A, Yamada R, et al. (2002) Functional SNPs in the lymphotoxin-alpha gene that are associated with susceptibility to myocardial infarction. Nat Genet 32: 650–654.
  25. 25. Wellcome Trust Case Control Consortium (2007) Genome-wide association study of 14,000 cases of seven common diseases and 3,000 shared controls. Nature 447: 661–678.
  26. 26. McCarthy MI, Abecasis GR, Cardon LR, Goldstein DB, Little J, et al. (2008) Genome-wide association studies for complex traits: consensus, uncertainty and challenges. Nat Rev Genet 9: 356–369.
  27. 27. Weinstein SL, Dolan LA, Cheng JC, Danielsson A, Morcuende JA (2008) Adolescent idiopathic scoliosis. Lancet 371: 1527–1537.
  28. 28. Lonstein JE, Carlson M (1984) The prediction of curve progression in untreated idiopathic scoliosis during growth. J Bone Joint Surg Am 66: 1061–1071.
  29. 29. Yeung HY, Tang NL, Lee KM, Ng BK, Hung VW, et al. (2006) Genetic association study of insulin-like growth factor-I (IGF-I) gene with curve severity and osteopenia in adolescent idiopathic scoliosis. Stud Health Technol Inform 123: 18–24.
  30. 30. Cha PC, Takahashi A, Hosono N, Low SK, Kamatani N, et al. (2011) A genome-wide association study identifies three loci associated with susceptibility to uterine fibroids. Nat Genet 43: 447–450.
  31. 31. Ohnishi Y, Tanaka T, Ozaki K, Yamada R, Suzuki H, et al. (2001) A high-throughput SNP typing system for genome-wide association studies. J Hum Genet 46: 471–477.
  32. 32. Gudmundsson J, Sulem P, Steinthorsdottir V, Bergthorsson JT, Thorleifsson G, et al. (2007) Two variants on chromosome 17 confer prostate cancer risk, and the one in TCF2 protects against type 2 diabetes. Nat Genet 39: 977–983.
  33. 33. Dy P, Wang W, Bhattaram P, Wang Q, Wang L, et al. (2012) Sox9 directs hypertrophic maturation and blocks osteoblast differentiation of growth plate chondrocytes. Dev Cell 22: 597–609.
  34. 34. Lekovic GP, Rekate HL, Dickman CA, Pearson M (2006) Congenital cervical instability in a patient with camptomelic dysplasia. Childs Nerv Syst 22: 1212–1214.
  35. 35. Wunderle VM, Critcher R, Hastie N, Goodfellow PN, Schedl A (1998) Deletion of long-range regulatory elements upstream of SOX9 causes campomelic dysplasia. Proc Natl Acad Sci U S A 95: 10649–10654.
  36. 36. Gordon CT, Tan TY, Benko S, Fitzpatrick D, Lyonnet S, et al. (2009) Long-range regulation at the SOX9 locus in development and disease. J Med Genet 46: 649–656.
  37. 37. Zhang X, Cowper-Sal lari R, Bailey SD, Moore JH, Lupien M (2012) Integrative functional genomics identifies an enhancer looping to the SOX9 gene disrupted by the 17q24.3 prostate cancer risk locus. Genome Res 22: 1437–1446.
  38. 38. Tristani-Firouzi M, Etheridge SP (2010) Kir 2.1 channelopathies: the Andersen-Tawil syndrome. Pflugers Arch 460: 289–294.
  39. 39. Plaster NM, Tawil R, Tristani-Firouzi M, Canun S, Bendahhou S, et al. (2001) Mutations in Kir2.1 cause the developmental and episodic electrical phenotypes of Andersen's syndrome. Cell 105: 511–519.
  40. 40. Lestner JM, Ellis R, Canham N (2012) Delineating the 17q24.2–q24.3 microdeletion syndrome phenotype. Eur J Med Genet 55: 700–704.
  41. 41. Blyth M, Huang S, Maloney V, Crolla JA, Karen Temple I (2008) A 2.3Mb deletion of 17q24.2-q24.3 associated with ‘Carney Complex plus’. Eur J Med Genet 51: 672–678.