Keywords
melogenesis imperfecta
hypoplasia
enamel
hypoplasia
enamel
How to Cite
Molecular mechanisms of amelogenesis imperfecta. A review of the ENAM, AMBN, FAM83H, MMP20 and KLK4 genes. (2021). Odontoestomatología, 23(38). https://doi.org/10.22592/1688-9339-ode-23-38-e306
Abstract
Amelogenesis imperfecta (AI) is an inherited disorder that affects the structure and clinical appearance of tooth enamel. Mutations of 18 genes have been associated as the
etiology of AI. The objective of this work is to update the current knowledge about ENAM, AMBN, FAM83H, MMP20 and KLK4 genes that cause the different types of AI.
Methodology: A bibliographic search was carried out considering scientific articles from 2003 to 2021 with regard to specific mutations in the aforementioned genes
in the following portals: scielo, Pubmed / MEDLINE, Cochrane and Springer Link.
Results: 37 articles met the inclusion criteria and were used for the development of this review.
Conclusions: Depending on the gene involved, enamel alterations can show a variety of characteristics. The biological mechanisms that lead to the disease are multiple
and varied, however many of them are not entirely clear yet, so more research will be required to improve our understanding of the subject.
References
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3. Crawford P.J; Aldred M; Bloch-Zupan A. Amelogenesis imperfecta. Orphanet J. Rare. Dis. 2007; 2: 17.
4. Hu J.C; Chun Y.H; Al Hazzazzi T; Simmer J.P. Enamel formation and amelogenesis imperfecta. Cellstissuesorgans. 2007; 186(1): 78-85.
5. Aldred M.J; Crawford P.J.M; Savarirayan R. Amelogenesis imperfecta: a classification and catalogue for the 21st century. Oral. Dis. 2003; 9(1): 19-23.
6. Prasad M.K; Laouina S; El Alloussi M; Dollfus H; Bloch-Zupan A. Amelogenesis imperfecta: 1 family, 2 phenotypes, and 2 mutated genes. J. Dent. Res. 2016; 95(13): 1457-1463.
7. Smith C.E.L; Poulter J.A; Antanaviciute A; Kirkham J; Brookes S.J; Inglehearn C.F; Mighell A.J. Amelogenesis Imperfecta; Genes, Proteins, and Pathways. Front. Physiol. 2017; 8: 435.
8. Kim J.W; Simmer J.P; Lin B.P.L; Seymen F; Bartlett J.D; Hu J.C.C. Mutational analysis of candidate
genes in 24 amelogenesis imperfecta families. Eur. J. Oral. Sci. 2006; 114(suppl1): 3-12.
9. Simancas-Escorcia V; Natera A; Acosta de Camargo M.G. Genes involved in amelogenesis imperfecta. Part I. Rev. Fac. Odontol. Univ. Antioq. 2018; 30(1): 105-120.
10. Lee S.K; Lee K.E; Jeong T.S; Hwang Y.H; Kim S; Hu J.C.C; Simmer J.P; Kim J.W. FAM83H mutations cause ADHCAI and alter intracellular protein localization. J. Dent. Res. 2011; 90(3): 377-381.
11. Kim J.W; Lee S.K; Lee Z.H; Park J.C; Lee K.E; Lee M.H. FAM83H mutations in families with autosomal-dominant hypocalcified amelogenesis imperfecta. Am. J. Hum. Genet. 2008; 82(2): 489-494.
12. Zhang H; Hu Y; Seymen F; Koruyucu M; Kasimoglu Y; Wang S.K; Wright J.T; Havel M.W; Zhang C; Kim J.W; Simmer J.P; Hu J.C.C. ENAM mutations and Digenic Inheritance. Mol. Genet. Genomic Med. 2019; 7(10): e928.
13. Koruyucu M; Kang J; Kim Y.J; Seymen F; Kasimoglu Y; Lee Z.H; Shin T.J; Hyun H.K; Kim Y.J; Lee S.H; Hu J.C.C; Simmer J.P; Kim J.W. Hypoplastic AI with highly variable expressivity caused by ENAM mutations. J. Dent. Res. 2018; 97(9): 1064-1069.
14. Seymen F; Lee K.E; Koruyucu M; Gencay K; Bayram M; Tuna E.B; Lee Z.H; Kim J.W. ENAM mutations with Incomplete Penetrance. J. Dent. Res. 2014; 93(10): 988-992.
15. Wang X; Zhao Y; Yang Y; Qin M. Novel ENAM and LAMB3 mutations in chinese families with hypoplastic amelogenesis imperfecta. Plos One. 2015; 10(3): e0116514.
16. Hart T.C; Hart P.S; Gorry M.C; Michalec M.D; Ryu O.H; Uygur C; Ozdemir D; Firatli S; Aren G; Firatli E. Novel ENAM mutation responsible for autosomal recessive amelogenesis imperfecta and localised enamel defects. J. Med. Genet. 2003; 40(12): 900-906.
17. Siddiqui S; Al-Jawad M. Enamelin directs crystallite organization at the enamel-dentine junction. J. Dent. Res. 2016; 95(5): 580-587.
18. Brookes S.J; Barron M.J; Smith C.E.L; Poulter J.A; Mighell A.J; Inglehearn C.F; Brown C.J; Rodd H; Kirkham J; Dixon M.J. Amelogenesis imperfecta caused by N-Terminal enamelin point mutations in mice and men is driven by endoplasmic reticulum stress. Hum. Mol. Genet. 2017; 26(10): 1863-1876.
19. Delsuc F; Gasse B; Sire J.Y. Evolutionary analysis of selective constraints identifies ameloblastin (AMBN) as a potential candidate for amelogenesis imperfecta. BMC Evolutionary Biology. 2015; 15: 148.
20. Poulter J.A; Murillo G; Brookes S.J; Smith C.E.L; Parry D.A; Silva S; Kirkham J; Inglehearn C.F; Mighell A.J. Deletion of ameloblastin exon 6 is associated with amelogenesis imperfecta. Hum. Mol. Genet. 2014; 23(20): 5317-5324.
21. Fukumoto S; Kiba T; Hall B; Iehara N; Nakamura T; Longenecker G; Krebsbach P.H; Nanci A; Kulkarni A.B; Yamada Y. Ameloblastin is a cell adhesion molecule required for maintaining the differentiation state of ameloblasts. J. Cell Biol. 2004; 167(5): 973-983.
22. Sire J.Y; Davit-Béal T; Delgado S; Gu X. The origin and evolution of enamel mineralization genes. Cells Tissues Organs. 2007; 186(1): 25-48.
23. Liang T; Hu Y; Smith C.E; Richardson A.S; Zhang H; Yang J; Lin B; Wang S.K; Kim J.W; Chun Y.H; Simmer J.P; Hu J.C.C. AMBN mutations causing hypoplastic amelogenesis imperfecta and Ambn knockout-NLS-laczknockin mice exhibiting failed amelogenesis and Ambn tissue-specificity. Mol. Genet. Genomic Med. 2019; 7(9): e929.
24. Lu T; Li M; Xu X; Xiong J; Huang C; Zhang X; Hu A; Peng L; Cai D; Zhang L; Wu B; Xiong F. Whole exome sequencing identifies an AMBN missense mutation causing severe autosomal-dominant amelogenesis imperfecta and dentin disorders. Int. J. Oral Sci. 2018; 10(3): 26.
25. Wang S.K; Zhang H; Hu C.Y; Liu J.F; Chadha S; Kim J.W; Simmer J.P; Hu J.C.C. FAM83H and autosomal dominant hypocalcified amelogenesis imperfecta. J. Dent. Res. 2021; 100(3): 293-301.
26. Urzua B; Martinez C; Ortega-Pinto A; Adorno D; Morales-Bozo I; Riadi G; Jara L; Plaza A; Lefimil C; Lozano C; Reyes M. Novel missense mutation of the FAM83H gene causes retention of amelogenin and a mild clinical phenotype of hypocalcified enamel. Arch. Oral Biol. 2015; 60(9): 1356-1367.
27. Wang S.K; Hu Y; Yang J; Smith C.E; Richardson A.S; Yamakoshi Y; Lee Y.L; Seymen F; Koruyucu M; Gencay K; Lee M; Choi M; Kim J.W; Hu J.C.C; Simmer J.P. Fam83h null mice support a neomorphic mechanism for human ADHCAI. Mol. Genet. Genomic Med. 2015; 4(1): 46-67.
28. Wang S.K; Hu Y; Smith C.E; Yang J; Zeng C; Kim J.W; Hu J.C.C; Simmer J.P. The enamel phenotype in homozygous Fam83h truncation mice. Mol. Genet. Genomic Med. 2019; 7(6): e724.
29. Zheng, Y; Lu T; Chen J; Li M; Xiong J; He F; Gan Z; Guo Y; Zhang L; Xiong F. The gain-of-function FAM83H mutation caused hypocalcification amelogenesis imperfecta in a chinese family. Clin. Oral Invest. 2021; 25(5): 2915-2923.
30. Xin W; Wenjun W; Man Q; Yuming Z. Novel FAM83H mutations in patients with amelogenesis imperfecta. Sci. Rep. 2017; 7(1): 6075.
31. Yu S; Quan J; Wang X; Sun X; Zhang X; Liu Y; Zhang C; Zheng S. A novel FAM83H mutation in one Chinese family with autosomal-dominant hypocalcification amelogenesis imperfecta. Mutagenesis. 2018; 33(4): 333-340.
32. Zhang C; Song Y; Bian Z; Ultrastructural analysis of the teeth affected with amelogenesis imperfecta resulting from FAM83H mutations and review of the literatures. Oral Surg. Oral Med. Oral Pathol. Oral Radiol. 2015; 119(2): e69-76.
33. Kuga T; Sasaki M; Mikami T; Miake Y; Adachi J; Shimizu M; Saito Y; Koura M; Takeda Y; Matsuda J; Tomonaga T; Nakayama Y. FAM83H and casein kinase I regulate the organization of the keratin cytoskeleton and formation of desmosomes. Sci. Rep. 2016; 6: 26557.
34. Gasse B; Prasad M; Delgado S; Huckert M; Kawczynski M; Garret-Bernardin A; Lopez-Cazaux S; Bailleul-Forestier I; Manière M.C; Stoetzel C; Bloch-Zupan A; Sire J.Y. Evolutionary analysis predicts sensitive positions of MMP20 and validates newly-and previously-identified MMP20 mutations causing amelogenesis imperfecta. Front. Physiol. 2017; 8: 398.
35. Wang S.K; Zhang H; Chavez M.B; Hu Y; Seymen F; Koruyucu M; Kasimoglu Y; Colvin C.D; Kolli T.N; Tan M.H; Wang Y.L; Lu P.Y; Kim J.W; Foster B.L; Bartlett J.D; Simmer J.P; Hu J.C.C. Dental malformations associated with biallelic MMP20 mutations. Mol. Genet. Genomic Med. 2020; 8(8): e1307.
36. Seymen F; Park J.C; Lee K.E; Lee H.K; Lee D.S; Koruyucu M; Gencay K; Bayram M; Tuna E.B; Lee Z.H; Kim Y.J; Kim J.W. Novel MMP20 and KLK4 mutations in amelogenesis imperfecta. J. Dent. Res. 2015; 94(8): 1063-1069.
37. Kim Y.J; Kang J; Seymen F; Koruyucu M; Zhang H; Kasimoglu Y; Bayram M; Tuna-Ince E.B; Bayrak
S; Tuloglu N; Hu J.C.C; Simmer J.P; Kim J.W. Alteration of exon definition causes amelogenesis imperfecta. J. Dent. Res. 2020; 99(4): 410-418.
38. Kim Y.J; Kang J; Seymen F; Koruyucu M; Gencay K; Shin T.J; Hyun H.K; Lee Z.H; Hu J.C.C; Simmer J.P; Kim J.W. Analyses of MMP20 missense mutations in two families with hypomaturation amelogenesis imperfecta. Front. Physiol. 2017; 8: 229.
39. Hu Y; Smith C.E; Richardson A.S; Bartlett J.D; Hu J.C; Simmer J.P. MMP20, KLK4, and MMP20/KLK4 double null mice define roles for matrix proteases during dental enamel formation. Mol. Genet. Genomic Med. 2015; 4(2): 178-196.
40. Smith C.E.L; Kirkham J; Day P.F; Soldani F; mcderra E.J; Poulter J.A; Inglehearn C.F; Mighell A.J; Brookes S.J. A fourth KLK4 mutation is associated with enamel hypomineralisation and structural abnormalities. Front. Physiol. 2017; 8: 333.
41. Hart P.S; Hart T.C; Michalec M.D; Ryu, O.H; Simmons D; Hong S; Wright J.T. Mutation in kallikrein 4 causes autosomal recessive hypomaturation amelogenesis imperfecta. J. Med. Genet. 2004; 41(7): 545-549.
42. Wang S.K; Hu Y; Simmer J.P; Seymen F; Estrella N.M.R.P; Pal S; Reid B.M; Yildirim M; Bayram M; Bartlett J.D; Hu J.C.C. Novel KLK4 and MMP20 mutations discovered by whole-exome sequencing. J. Dent. Res. 2013; 92(3): 266-271.
2. Witkop C.J. Jr. Amelogenesis imperfecta, dentinogenesisimperfecta and dentin dysplasia revisited: problems in classification. J. Oral. Pathol. 1988; 17(9-10): 547-553.
3. Crawford P.J; Aldred M; Bloch-Zupan A. Amelogenesis imperfecta. Orphanet J. Rare. Dis. 2007; 2: 17.
4. Hu J.C; Chun Y.H; Al Hazzazzi T; Simmer J.P. Enamel formation and amelogenesis imperfecta. Cellstissuesorgans. 2007; 186(1): 78-85.
5. Aldred M.J; Crawford P.J.M; Savarirayan R. Amelogenesis imperfecta: a classification and catalogue for the 21st century. Oral. Dis. 2003; 9(1): 19-23.
6. Prasad M.K; Laouina S; El Alloussi M; Dollfus H; Bloch-Zupan A. Amelogenesis imperfecta: 1 family, 2 phenotypes, and 2 mutated genes. J. Dent. Res. 2016; 95(13): 1457-1463.
7. Smith C.E.L; Poulter J.A; Antanaviciute A; Kirkham J; Brookes S.J; Inglehearn C.F; Mighell A.J. Amelogenesis Imperfecta; Genes, Proteins, and Pathways. Front. Physiol. 2017; 8: 435.
8. Kim J.W; Simmer J.P; Lin B.P.L; Seymen F; Bartlett J.D; Hu J.C.C. Mutational analysis of candidate
genes in 24 amelogenesis imperfecta families. Eur. J. Oral. Sci. 2006; 114(suppl1): 3-12.
9. Simancas-Escorcia V; Natera A; Acosta de Camargo M.G. Genes involved in amelogenesis imperfecta. Part I. Rev. Fac. Odontol. Univ. Antioq. 2018; 30(1): 105-120.
10. Lee S.K; Lee K.E; Jeong T.S; Hwang Y.H; Kim S; Hu J.C.C; Simmer J.P; Kim J.W. FAM83H mutations cause ADHCAI and alter intracellular protein localization. J. Dent. Res. 2011; 90(3): 377-381.
11. Kim J.W; Lee S.K; Lee Z.H; Park J.C; Lee K.E; Lee M.H. FAM83H mutations in families with autosomal-dominant hypocalcified amelogenesis imperfecta. Am. J. Hum. Genet. 2008; 82(2): 489-494.
12. Zhang H; Hu Y; Seymen F; Koruyucu M; Kasimoglu Y; Wang S.K; Wright J.T; Havel M.W; Zhang C; Kim J.W; Simmer J.P; Hu J.C.C. ENAM mutations and Digenic Inheritance. Mol. Genet. Genomic Med. 2019; 7(10): e928.
13. Koruyucu M; Kang J; Kim Y.J; Seymen F; Kasimoglu Y; Lee Z.H; Shin T.J; Hyun H.K; Kim Y.J; Lee S.H; Hu J.C.C; Simmer J.P; Kim J.W. Hypoplastic AI with highly variable expressivity caused by ENAM mutations. J. Dent. Res. 2018; 97(9): 1064-1069.
14. Seymen F; Lee K.E; Koruyucu M; Gencay K; Bayram M; Tuna E.B; Lee Z.H; Kim J.W. ENAM mutations with Incomplete Penetrance. J. Dent. Res. 2014; 93(10): 988-992.
15. Wang X; Zhao Y; Yang Y; Qin M. Novel ENAM and LAMB3 mutations in chinese families with hypoplastic amelogenesis imperfecta. Plos One. 2015; 10(3): e0116514.
16. Hart T.C; Hart P.S; Gorry M.C; Michalec M.D; Ryu O.H; Uygur C; Ozdemir D; Firatli S; Aren G; Firatli E. Novel ENAM mutation responsible for autosomal recessive amelogenesis imperfecta and localised enamel defects. J. Med. Genet. 2003; 40(12): 900-906.
17. Siddiqui S; Al-Jawad M. Enamelin directs crystallite organization at the enamel-dentine junction. J. Dent. Res. 2016; 95(5): 580-587.
18. Brookes S.J; Barron M.J; Smith C.E.L; Poulter J.A; Mighell A.J; Inglehearn C.F; Brown C.J; Rodd H; Kirkham J; Dixon M.J. Amelogenesis imperfecta caused by N-Terminal enamelin point mutations in mice and men is driven by endoplasmic reticulum stress. Hum. Mol. Genet. 2017; 26(10): 1863-1876.
19. Delsuc F; Gasse B; Sire J.Y. Evolutionary analysis of selective constraints identifies ameloblastin (AMBN) as a potential candidate for amelogenesis imperfecta. BMC Evolutionary Biology. 2015; 15: 148.
20. Poulter J.A; Murillo G; Brookes S.J; Smith C.E.L; Parry D.A; Silva S; Kirkham J; Inglehearn C.F; Mighell A.J. Deletion of ameloblastin exon 6 is associated with amelogenesis imperfecta. Hum. Mol. Genet. 2014; 23(20): 5317-5324.
21. Fukumoto S; Kiba T; Hall B; Iehara N; Nakamura T; Longenecker G; Krebsbach P.H; Nanci A; Kulkarni A.B; Yamada Y. Ameloblastin is a cell adhesion molecule required for maintaining the differentiation state of ameloblasts. J. Cell Biol. 2004; 167(5): 973-983.
22. Sire J.Y; Davit-Béal T; Delgado S; Gu X. The origin and evolution of enamel mineralization genes. Cells Tissues Organs. 2007; 186(1): 25-48.
23. Liang T; Hu Y; Smith C.E; Richardson A.S; Zhang H; Yang J; Lin B; Wang S.K; Kim J.W; Chun Y.H; Simmer J.P; Hu J.C.C. AMBN mutations causing hypoplastic amelogenesis imperfecta and Ambn knockout-NLS-laczknockin mice exhibiting failed amelogenesis and Ambn tissue-specificity. Mol. Genet. Genomic Med. 2019; 7(9): e929.
24. Lu T; Li M; Xu X; Xiong J; Huang C; Zhang X; Hu A; Peng L; Cai D; Zhang L; Wu B; Xiong F. Whole exome sequencing identifies an AMBN missense mutation causing severe autosomal-dominant amelogenesis imperfecta and dentin disorders. Int. J. Oral Sci. 2018; 10(3): 26.
25. Wang S.K; Zhang H; Hu C.Y; Liu J.F; Chadha S; Kim J.W; Simmer J.P; Hu J.C.C. FAM83H and autosomal dominant hypocalcified amelogenesis imperfecta. J. Dent. Res. 2021; 100(3): 293-301.
26. Urzua B; Martinez C; Ortega-Pinto A; Adorno D; Morales-Bozo I; Riadi G; Jara L; Plaza A; Lefimil C; Lozano C; Reyes M. Novel missense mutation of the FAM83H gene causes retention of amelogenin and a mild clinical phenotype of hypocalcified enamel. Arch. Oral Biol. 2015; 60(9): 1356-1367.
27. Wang S.K; Hu Y; Yang J; Smith C.E; Richardson A.S; Yamakoshi Y; Lee Y.L; Seymen F; Koruyucu M; Gencay K; Lee M; Choi M; Kim J.W; Hu J.C.C; Simmer J.P. Fam83h null mice support a neomorphic mechanism for human ADHCAI. Mol. Genet. Genomic Med. 2015; 4(1): 46-67.
28. Wang S.K; Hu Y; Smith C.E; Yang J; Zeng C; Kim J.W; Hu J.C.C; Simmer J.P. The enamel phenotype in homozygous Fam83h truncation mice. Mol. Genet. Genomic Med. 2019; 7(6): e724.
29. Zheng, Y; Lu T; Chen J; Li M; Xiong J; He F; Gan Z; Guo Y; Zhang L; Xiong F. The gain-of-function FAM83H mutation caused hypocalcification amelogenesis imperfecta in a chinese family. Clin. Oral Invest. 2021; 25(5): 2915-2923.
30. Xin W; Wenjun W; Man Q; Yuming Z. Novel FAM83H mutations in patients with amelogenesis imperfecta. Sci. Rep. 2017; 7(1): 6075.
31. Yu S; Quan J; Wang X; Sun X; Zhang X; Liu Y; Zhang C; Zheng S. A novel FAM83H mutation in one Chinese family with autosomal-dominant hypocalcification amelogenesis imperfecta. Mutagenesis. 2018; 33(4): 333-340.
32. Zhang C; Song Y; Bian Z; Ultrastructural analysis of the teeth affected with amelogenesis imperfecta resulting from FAM83H mutations and review of the literatures. Oral Surg. Oral Med. Oral Pathol. Oral Radiol. 2015; 119(2): e69-76.
33. Kuga T; Sasaki M; Mikami T; Miake Y; Adachi J; Shimizu M; Saito Y; Koura M; Takeda Y; Matsuda J; Tomonaga T; Nakayama Y. FAM83H and casein kinase I regulate the organization of the keratin cytoskeleton and formation of desmosomes. Sci. Rep. 2016; 6: 26557.
34. Gasse B; Prasad M; Delgado S; Huckert M; Kawczynski M; Garret-Bernardin A; Lopez-Cazaux S; Bailleul-Forestier I; Manière M.C; Stoetzel C; Bloch-Zupan A; Sire J.Y. Evolutionary analysis predicts sensitive positions of MMP20 and validates newly-and previously-identified MMP20 mutations causing amelogenesis imperfecta. Front. Physiol. 2017; 8: 398.
35. Wang S.K; Zhang H; Chavez M.B; Hu Y; Seymen F; Koruyucu M; Kasimoglu Y; Colvin C.D; Kolli T.N; Tan M.H; Wang Y.L; Lu P.Y; Kim J.W; Foster B.L; Bartlett J.D; Simmer J.P; Hu J.C.C. Dental malformations associated with biallelic MMP20 mutations. Mol. Genet. Genomic Med. 2020; 8(8): e1307.
36. Seymen F; Park J.C; Lee K.E; Lee H.K; Lee D.S; Koruyucu M; Gencay K; Bayram M; Tuna E.B; Lee Z.H; Kim Y.J; Kim J.W. Novel MMP20 and KLK4 mutations in amelogenesis imperfecta. J. Dent. Res. 2015; 94(8): 1063-1069.
37. Kim Y.J; Kang J; Seymen F; Koruyucu M; Zhang H; Kasimoglu Y; Bayram M; Tuna-Ince E.B; Bayrak
S; Tuloglu N; Hu J.C.C; Simmer J.P; Kim J.W. Alteration of exon definition causes amelogenesis imperfecta. J. Dent. Res. 2020; 99(4): 410-418.
38. Kim Y.J; Kang J; Seymen F; Koruyucu M; Gencay K; Shin T.J; Hyun H.K; Lee Z.H; Hu J.C.C; Simmer J.P; Kim J.W. Analyses of MMP20 missense mutations in two families with hypomaturation amelogenesis imperfecta. Front. Physiol. 2017; 8: 229.
39. Hu Y; Smith C.E; Richardson A.S; Bartlett J.D; Hu J.C; Simmer J.P. MMP20, KLK4, and MMP20/KLK4 double null mice define roles for matrix proteases during dental enamel formation. Mol. Genet. Genomic Med. 2015; 4(2): 178-196.
40. Smith C.E.L; Kirkham J; Day P.F; Soldani F; mcderra E.J; Poulter J.A; Inglehearn C.F; Mighell A.J; Brookes S.J. A fourth KLK4 mutation is associated with enamel hypomineralisation and structural abnormalities. Front. Physiol. 2017; 8: 333.
41. Hart P.S; Hart T.C; Michalec M.D; Ryu, O.H; Simmons D; Hong S; Wright J.T. Mutation in kallikrein 4 causes autosomal recessive hypomaturation amelogenesis imperfecta. J. Med. Genet. 2004; 41(7): 545-549.
42. Wang S.K; Hu Y; Simmer J.P; Seymen F; Estrella N.M.R.P; Pal S; Reid B.M; Yildirim M; Bayram M; Bartlett J.D; Hu J.C.C. Novel KLK4 and MMP20 mutations discovered by whole-exome sequencing. J. Dent. Res. 2013; 92(3): 266-271.