1+2/2010 - Společnost pro pojivové tkáně

AI is a heterogenious genetic disorderwhich affects the dental enamel. It canhave an AD, AR or XL mendelian inheritancepattern.The cause of XL, AI is definitely relatedto defects in the amelogenin gene(Xp221.1–22.3). Amelogenin is the principialprotein to the formation of humandental enamel. The formation is controlledin ameloblasts through the interactionof a number of organic matrix moleculesthat include enamelin, amelogenin, ameloblastin,tuftelin, amelotin, dentin sialoproteinand a variety of enzymes such as kallikreinand matrix metalloproteinases MP.The production of the initial enamellayer which covers the dentin is connectedwith the formation of a network of pits onits surface. Dental enamel is higher mineralisedtissue, more hard as the bone.We recognize presecretory stage ofamelogenesis, stage of proliferation,secretory stage and maturation (when theenamel increases its mineral content to80–90 % of its weight). During maturation25 % of ameloblasts die.The heredity disturbancies of stagesI. are AD, AR, XL, stages II. are AD or AR,stages III. AR or AD, stages IV AD.Multiple gene defect responsible forcausing AI have been identified since 1990,not of AI types known molecular basis.The mutation caused AI are in theAMELX – amelogenin, localized at chromozome(Xp22.23-p22.1), ENAM – enamelin(4q13.34). MMP 20 20 (11q22.3-q23), KLK4 – kalikrein, enamelysin, AMBN – ameloblastin(4q21), TUFT 1 – tuftelin (1q21),AMELOTIN (4q13), DSPP (4q213).Case reportsFamily 1 were 3 affected persons: siblings– brother and sister and their fatherwere examined. Both dentition wereaffected. The diagnosis were estimated inthe age two years. Another else personsfrom father side were affected (10 personsin 5 generation). This is AD inheritance.Family 2 – two brothers are patientswith AI. It is affection from the fathers sideof the pedigree. 4 persons were affected inthe 3 generations. This is AD transmission.Family 3: Father and son are affected. Itis AD transmission in two generation.Family 4 – isolated case, female, probablyfresh – new mutation.Family 5 – related to family 1, commonancester with the family 1. AD transmission,10 persons affected.Family 6 – female, isolated case, bothdentition affected, fresh – new mutationprobably (?). Pedigree non informativeResults and conclusionsAI was examined by 8 our patients from6 families. The main clinical processes of AIare esthetics, dental sensitivity and loss ofocclusal vertical dimensions. The severityof dental signs variees with each type of AI.122LOCOMOTOR SYSTEM vol. 17, 2010, No. 1+2