  Hutchinson-Gilford Progeria syndrome, Werner syndrome, and Cockayne syndrome
are three genetic disorders, in which the children have premature aging
features. To understand the phenomenon of premature aging, the similarity of
aging features in these syndromes to that in normal aging is investigated.
Although these three syndromes have different genetic backgrounds, all the
patients have abnormal structures of tissues/organs like that in normal aging.
Therefore, the abnormality in tissue structure is the common point in premature
aging and normal aging. This abnormality links also a defective development and
a defective repair, the Misrepair. Defective development is a result of
Mis-construction of the structure of tissues and organs as consequence of
genetic mutations. Aging is a result of Mis-reconstructions, the Misrepairs,
for maintaining the structure of tissues/organs. Construction-reconstruction of
the structure of an organism is thus the coupling point of development and
aging. Mis- construction and Mis-reconstruction (Misrepair) are the essential
processes for the development of aging-like feathers. In conclusion, premature
aging is a result of Mis- construction of tissues and organs during body
development as consequence of genetic disorders.
