Inheritance of hypodontia in twins.
The aim of this study was to establish prevalence of hypodontia in the twin sample and to assess the degree of its heritability. A study was performed in a sample of 96 twin pairs, 38 pairs being monozygotic (MZ) and 58 pairs dizygotic (DZ), from north-west Croatia. The sample included 25.82% of all twins born in the region during a ten-year period. The twin zygosity was determined according to the WHO recommendations (1996). A revised Holzinger's index (Hc') according to Allen was applied to calculate the degree of heritability. Hypodontia was found in 22 out of the total of 192 twins analyzed (11.5%). Among 96 pairs of twins, hypodontia was observed in 17 pairs (7 MZ and 10 DZ pairs). Among the MZ, 4 pairs were found to be concordant for hypodontia, among the DZ one pair only. The heritability index was 0825. A prevalence of hypodontia in twins observed in this study is significantly higher than in the general population. A high index of heritability (Hc' = 0.825) points to a high genetic determination.
Lapter
M
M
Department of Orthodontics, School of Dentistry, University of Zagreb, Croatia.
Slaj
M
M
Skrinjarić
I
I
Muretić
Z
Z
D000293:Adolescent; D000848:Anodontia / Q000453:epidemiology / Q000235:genetics*; D002648:Child; D002675:Child, Preschool; D017523:Croatia / Q000453:epidemiology; D004200:Diseases in Twins; D006801:Humans; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic