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1.
J Dent Res ; 101(1): 37-45, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34036831

RESUMEN

Amelogenesis imperfecta (AI) is an innate disorder that affects the formation and mineralization of the tooth enamel. When diagnosed with AI, one's teeth can be hypoplastic (thin enamel), hypomature (normal enamel thickness but discolored and softer than normal enamel), hypocalcified (normal enamel thickness but extremely weak), or mixed conditions of the above. Numerous studies have revealed the genes that are involved in causing AI. Recently, ACP4 (acid phosphatase 4) was newly found as a gene causing hypoplastic AI, and it was suggested that mutant forms of ACP4 might affect access to the catalytic core or the ability to form a homodimer. In this study, a Korean and a Turkish family with hypoplastic AI were recruited, and their exome sequences were analyzed. Biallelic mutations were revealed in ACP4: paternal (NM_033068: c.419C>T, p.(Pro140Leu)) and maternal (c.262C>A, p.(Arg88Ser)) mutations in family 1 and a paternal (c.713C>T, p.(Ser238Leu)) mutation and de novo (c.350A>G, p.(Gln117Arg)) mutation in the maternal allele in family 2. Mutations were analyzed by cloning, mutagenesis, immunofluorescence, immunoprecipitation, and acid phosphatase activity test. Comparison between the wild-type and mutant ACP4s showed a decreased amount of protein expression from the mutant forms, a decreased ability to form a homodimer, and a decreased acid phosphatase activity level. We believe that these findings will not only expand the mutational spectrum of ACP4 but also increase our understanding of the mechanism of ACP4 function during normal and pathologic amelogenesis.


Asunto(s)
Fosfatasa Ácida/genética , Amelogénesis Imperfecta , Diente , Amelogénesis Imperfecta/genética , Esmalte Dental , Humanos , Mutación/genética , Linaje
2.
J Dent Res ; 99(4): 410-418, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-31999931

RESUMEN

Amelogenesis imperfecta (AI) is a collection of genetic disorders affecting the quality and/or quantity of tooth enamel. More than 20 genes are, so far, known to be responsible for this condition. In this study, we recruited 3 Turkish families with hypomaturation AI. Whole-exome sequence analyses identified disease-causing mutations in each proband, and these mutations cosegregated with the AI phenotype in all recruited members of each family. The AI-causing mutations in family 1 were a novel AMELX mutation [NM_182680.1:c.143T>C, p.(Leu48Ser)] in the proband and a novel homozygous MMP20 mutation [NM_004771.3:c.616G>A, p.(Asp206Asn)] in the mother of the proband. Previously reported compound heterozygous MMP20 mutations [NM_004771.3:c.103A>C, p.(Arg35=) and c.389C>T, p.(Thr130Ile)] caused the AI in family 2 and family 3. Minigene splicing analyses revealed that the AMELX missense mutation increased exonic definition of exon 4 and the MMP20 synonymous mutation decreased exonic definition of exon 1. These mutations would trigger an alteration of exon usage during RNA splicing, causing the enamel malformations. These results broaden our understanding of molecular genetic pathology of tooth enamel formation.


Asunto(s)
Amelogénesis Imperfecta , Amelogénesis Imperfecta/genética , Esmalte Dental , Exones/genética , Humanos , Mutación , Linaje
3.
Eur J Paediatr Dent ; 20(2): 105-110, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31246084

RESUMEN

AIM: Indirect pulp capping (IPC) is a treatment that preserves pulp vitality. Several materials have been used for this procedure. The aim of this study is to evaluate the radiographic and clinical outcomes of TheraCal LC (Bisco Inc., Schaumburg, IL, USA) and to compare it with mineral trioxide aggregate (MTA) (Pro Root MTA, Dentsply Tulsa, Johnson City, TN, USA) and calcium hydroxide [Ca(OH)2] (Dycal, Dentsply De Trey Konstanz, Germany) biomaterials in IPC treatment. MATERIALS AND METHODS: A total of 295 teeth, including second primary molars and first permanent molars with IPC indications from healthy and cooperative children aged between 4-15 years, were included in this study. Teeth were divided into three groups according to the materials used for pulp capping. Indirect pulp treatment was applied using Dycal for 91 teeth, ProRoot MTA for 89 teeth and TheraCal LC for 115 teeth. Primary molars were restored with the compomer material, and permanent molars were restored with the resin composite material. Restorations were evaluated with the Modified United States Public Health Service (modified USPHS) criteria. Clinical and radiographic findings were evaluated for 24 months at follow-up. STATISTICS: Statistical analysis was performed using the IBM SPSS Statistics 22 (IBM SPSS, Turkey) program, with descriptive statistical methods (means, standard deviations) and Chi-square, Fisher's exact test, and Yates's continuity correction (p<0.05 significance level) to evaluate the data. RESULTS: There were no statistically significant differences between the materials (p>0.05). The respective success rates of ProRoot MTA, Theracal LC, and Dycal were 94.4%, 87.8%, and 84.6%. There was no statistically significant difference between primary and permanent teeth according to the modified USPHS criteria (p>0.05). CONCLUSION: These results support the idea that the success of IPC is independent from the capping material. Recently produced calcium-silicate based materials can also be used for IPC. The most important factors are to apply the indirect pulp treatment carefully, avoiding bacterial contamination, and to seal the teeth with hermetic restoration. More clinical studies with longer follow-up periods are required for understanding the clinical efficiency of these materials.


Asunto(s)
Recubrimiento de la Pulpa Dental , Materiales de Recubrimiento Pulpar y Pulpectomía , Adolescente , Compuestos de Aluminio , Compuestos de Calcio , Niño , Preescolar , Pulpa Dental , Combinación de Medicamentos , Estudios de Seguimiento , Humanos , Óxidos , Silicatos , Turquía
4.
J Dent Res ; 98(5): 541-548, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30779877

RESUMEN

Dental enamel malformations, or amelogenesis imperfecta (AI), can be isolated or syndromic. To improve the prospects of making a successful diagnosis by genetic testing, it is important that the full range of genes and mutations that cause AI be determined. Defects in WDR72 (WD repeat-containing protein 72; OMIM *613214) cause AI, type IIA3 (OMIM #613211), which follows an autosomal recessive pattern of inheritance. The defective enamel is normal in thickness, severely hypomineralized, orange-brown stained, and susceptible to attrition. We identified 6 families with biallelic WDR72 mutations by whole exome sequence analyses that perfectly segregated with the enamel phenotype. The novel mutations included 3 stop-gains [NM_182758.2: c.377G>A/p.(Trp126*), c.1801C>T/p.(Arg601*), c.2350A>T/p.(Arg784*)], a missense mutation [c.1265G>T/p.(Gly422Val)], and a 62,138-base pair deletion (NG_017034.2: g.35441_97578del62138) that removed WDR72 coding exons 3 through 13. A previously reported WDR72 frameshift was also observed [c.1467_1468delAT/p.(Val491Aspfs*8)]. Three of the affected patients showed decreased serum pH, consistent with a diagnosis of renal tubular acidosis. Percentiles of stature and body weight varied among 8 affected individuals but did not show a consistent trend. These studies support that WDR72 mutations cause a syndromic form of AI and improve our ability to diagnose AI caused by WDR72 defects.


Asunto(s)
Acidosis , Amelogénesis Imperfecta , Proteínas/inmunología , Acidosis/genética , Amelogénesis Imperfecta/genética , Humanos , Mutación , Linaje
5.
J Dent Res ; 97(9): 1064-1069, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-29554435

RESUMEN

Tooth enamel, the hardest tissue in the human body, is formed after a complex series of interactions between dental epithelial tissue and the underlying ectomesenchyme. Nonsyndromic amelogenesis imperfecta (AI) is a rare genetic disorder affecting tooth enamel without other nonoral symptoms. In this study, we identified 2 novel ENAM mutations in 2 families with hypoplastic AI by whole exome sequencing. Family 1 had a heterozygous splicing donor site mutation in intron 4, NM_031889; c.123+2T>G. Affected individuals had hypoplastic enamel with or without the characteristic horizontal hypoplastic grooves in some teeth. Family 2 had a nonsense mutation in the last exon, c.1842C>G, p.(Tyr614*), that was predicted to truncate the protein by 500 amino acids. Participating individuals had at least 1 mutant allele, while the proband had a homozygous mutation. Most interestingly, the clinical phenotype of the individuals harboring the heterozygous mutation varied from a lack of penetrance to a mild hypoplastic enamel defect. We believe that these findings will broaden our understanding of the clinical phenotype of AI caused by ENAM mutations.


Asunto(s)
Amelogénesis Imperfecta/genética , Proteínas de la Matriz Extracelular/genética , Mutación/genética , Niño , Consanguinidad , Femenino , Humanos , Linaje , Fenotipo , Reacción en Cadena de la Polimerasa , Turquía , Secuenciación del Exoma , Adulto Joven
6.
Oral Dis ; 22(4): 297-302, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26762616

RESUMEN

OBJECTIVE: To identify the molecular genetic aetiology of a family with autosomal dominant amelogenesis imperfecta (AI). SUBJECTS AND METHODS: DNA samples were collected from a six-generation family, and the candidate gene approach was used to screen for the enamelin (ENAM) gene. Whole-exome sequencing and linkage analysis with SNP array data identified linked regions, and candidate gene screening was performed. RESULTS: Mutational analysis revealed a mutation (c.561_562delCT and p.Tyr188Glnfs*13) in the DLX3 gene. After finding a recurrent DLX3 mutation, the clinical phenotype of the family members was re-examined. The proband's mother had pulp elongation in the third molars. The proband had not hair phenotype, but her cousin had curly hair at birth. CONCLUSIONS: In this study, we identified a recurrent 2-bp deletional DLX3 mutation in a new family. The clinical phenotype was the mildest one associated with the DLX3 mutations. These results will advance the understanding of the functional role of DLX3 in developmental processes.


Asunto(s)
Amelogénesis Imperfecta/genética , Secuencia de Bases , Proteínas de Homeodominio/genética , Eliminación de Secuencia , Factores de Transcripción/genética , Adulto , Amelogénesis Imperfecta/diagnóstico por imagen , Niño , Análisis Mutacional de ADN , Exoma , Femenino , Humanos , Masculino , Linaje , Fenotipo , Radiografía Dental
7.
J Dent Res ; 94(8): 1063-9, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26124219

RESUMEN

In order to achieve highly mineralized tooth enamel, enamel proteinases serve the important function of removing the remaining organic matrix in the mineralization and maturation of the enamel matrix. Mutations in the kallikrein 4 (KLK4), enamelysin (MMP20), and WDR72 genes have been identified as causing hypomaturation enamel defects in an autosomal-recessive hereditary pattern. In this report, 2 consanguineous families with a hypomaturation-type enamel defect were recruited, and mutational analysis was performed to determine the molecular genetic etiology of the disease. Whole exome sequencing and autozygosity mapping identified novel homozygous mutations in the KLK4 (c.620_621delCT, p.Ser207Trpfs*38) and MMP20 (c.1054G>A, p.Glu352Lys) genes. Further analysis on the effect of the mutations on the translation, secretion, and function of KLK4 and MMP20 revealed that mutant KLK4 was degraded intracellularly and became inactive while mutant MMP20 was expressed at a normal level but secreted only minimally with proteolytic function.


Asunto(s)
Amelogénesis Imperfecta/genética , Calicreínas/genética , Metaloproteinasa 20 de la Matriz/genética , Mutación , Amelogénesis Imperfecta/diagnóstico por imagen , Western Blotting , Niño , Consanguinidad , Femenino , Genotipo , Homocigoto , Humanos , Linaje , Reacción en Cadena de la Polimerasa , Polimorfismo de Nucleótido Simple , Radiografía Panorámica , Análisis de Secuencia de ADN
8.
Oral Dis ; 21(4): 456-61, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25431241

RESUMEN

OBJECTIVE: Hereditary defects in tooth enamel formation, amelogenesis imperfecta (AI), can be non-syndromic or syndromic phenotype. Integrins are signaling proteins that mediate cell-cell and cell-extracellular matrix communication, and their involvement in tooth development is well known. The purposes of this study were to identify genetic cause of an AI family and molecular pathogenesis underlying defective enamel formation. MATERIALS AND METHODS: We recruited a Turkish family with isolated AI and performed mutational analyses to clarify the underlying molecular genetic etiology. RESULTS: Autozygosity mapping and exome sequencing identified a novel homozygous ITGB6 transversion mutation in exon 4 (c.517G>C, p.Gly173Arg). The glycine at this position in the middle of the ßI-domain is conserved among a wide range of vertebrate orthologs and human paralogs. Clinically, the enamel was generally thin and pitted with pigmentation. Thicker enamel was noted at the cervical area of the molars. CONCLUSIONS: In this study, we identified a novel homozygous ITGB6 mutation causing isolated AI, and this advances the understanding of normal and pathologic enamel development.


Asunto(s)
Amelogénesis Imperfecta/etiología , Amelogénesis Imperfecta/genética , Cadenas beta de Integrinas/genética , Mutación , Amelogénesis/genética , Amelogénesis Imperfecta/sangre , Amelogénesis Imperfecta/diagnóstico por imagen , Niño , Análisis Mutacional de ADN , Exones , Femenino , Humanos , Diente Molar/patología , Linaje , Reacción en Cadena de la Polimerasa , Alineación de Secuencia , Turquía
9.
Eur Arch Paediatr Dent ; 16(1): 63-6, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25245233

RESUMEN

BACKGROUND: The Simpson-Golabi-Behmel syndrome (SGBS) is an overgrowth condition characterised by macrosomia, mental deficiency, large head, prominent skull sutures, midface deficiency, hypertelorism, broad nose, wide mouth, macroglossia, malocclusion, highly arched palate, and musculoskeletal and limb abnormalities. The aim of this case report is to present clinical and oral findings of an 8-year-old boy who had been diagnosed with SGBS. CASE REPORT: This patient had supernumerary nipples on the right side, cubitus valgus webbed fingers, scoliosis, umbilical hernia, a coarse face, macrocephaly, hypertelorism, a short broad nose, a wide mouth, a straight facial profile and hearing loss. The patient also had macroglossia, diastemas, over-retained primary tooth, absent mandibular permanent central incisors, and highly arched palate. Lateral cephalometric analysis revealed a large anterior cranial base, a large maxilla and mandible, a large inferior face height, and skeletal Class III jaw relationship. FOLLOW-UP: After extraction of the over-retained primary central tooth, a partial prosthesis was fabricated in order to maintain function. The patient has been recalled regularly at 6-month intervals for 2 years. Over the following years the prosthesis was replaced due to facial growth. CONCLUSION: Long term follow-up is essential for the patient with SGBS. Preventive dental care, including oral hygiene instructions, diet counselling and the use of fluoride has been implemented.


Asunto(s)
Anodoncia/diagnóstico , Arritmias Cardíacas/diagnóstico , Enfermedades Genéticas Ligadas al Cromosoma X/diagnóstico , Gigantismo/diagnóstico , Cardiopatías Congénitas/diagnóstico , Discapacidad Intelectual/diagnóstico , Macroglosia/diagnóstico , Maloclusión de Angle Clase III/diagnóstico , Cefalometría/métodos , Niño , Dentadura Parcial Removible , Diastema/patología , Estudios de Seguimiento , Humanos , Hipertelorismo/diagnóstico , Incisivo/anomalías , Macrostomía/diagnóstico , Masculino , Nariz/anomalías , Hueso Paladar/anomalías , Diente Primario/patología
10.
J Dent Res ; 93(10): 988-92, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25143514

RESUMEN

Amelogenesis imperfecta (AI) is a genetic disease affecting tooth enamel formation. AI can be an isolated entity or a phenotype of syndromes. To date, more than 10 genes have been associated with various forms of AI. We have identified 2 unrelated Turkish families with hypoplastic AI and performed mutational analysis. Whole-exome sequencing identified 2 novel heterozygous nonsense mutations in the ENAM gene (c.454G>T p.Glu152* in family 1, c.358C>T p.Gln120* in family 2) in the probands. Affected individuals were heterozygous for the mutation in each family. Segregation analysis within each family revealed individuals with incomplete penetrance or extremely mild enamel phenotype, in spite of having the same mutation with the other affected individuals. We believe that these findings will broaden our understanding of the clinical phenotype of AI caused by ENAM mutations.


Asunto(s)
Amelogénesis Imperfecta/genética , Codón sin Sentido/genética , Proteínas de la Matriz Extracelular/genética , Penetrancia , Adolescente , Niño , Segregación Cromosómica/genética , Codón de Terminación/genética , Consanguinidad , Citosina , Esmalte Dental/patología , Hipoplasia del Esmalte Dental/genética , Exoma/genética , Exones/genética , Femenino , Ácido Glutámico/genética , Glutamina/genética , Guanina , Heterocigoto , Humanos , Masculino , Fenotipo , Timina
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