title: The problem of determining twin zygosity for epidemiological studies.
abstract: The use of epidemiological studies of twins as a means of determining the existence of genetic factors in various conditions is well known. To be of value, the zygosity of the twin pairs must be identified with as great a degree of confidence as possible. A method of determining twin zygosity, using concordance in general likeness, hair colour, hair type, eye colour, ear form, tongue roll and phenylthiocarbamide (PTC) taste sensitivity, was developed for use in a survey of 244 pairs of like-sexed twins aged 5 to 15 years. The results obtained and the problems raised when applying this method are discussed. The method was sinple to apply to a large group of twin pairs, and monozygotic pairs were identified with a degree of confidence greater than 95%.
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D005127:Eye Color; D005260:Female; D005838:Genotype; D006200:Hair Color; D006801:Humans; D008297:Male; D010641:Phenotype; D011247:Pregnancy; D011336:Probability; D013649:Taste / Q000502:physiology; D014059:Tongue / Q000033:anatomy & histology; D014427:Twins; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic