06-3
Chapter One
Perspectives on Gene-based
Therapies
JEAN-MAURICE DELABAR
SUMMARY
Aneuploidies, i.e. disorders in the number of copies of functional genomic
elements, are common genomic disorders with a profound impact on the
health of human populations. The phenotypic consequences of aneuploidies
are numerous, and range from mental retardation and developmental abnormalities
to susceptibility to common phenotypes and to various neoplasms.
Trisomy 21 (Down syndrome, DS, T21) is the most frequent aneuploidy (1/700
births and 500 000 patients in Europe) and it is still, even after the improvements
of prenatal diagnosis, far outside the range of rare diseases (<1/2000).
This is one of the main genetic causes of mental retardation. This review
focuses on new strategies that might allow us to counter some of the adverse
effects of the phenotype.
DOWN SYNDROME AND PHENOTYPES
T21 exerts a powerful downward effect on the intelligence quotient (IQ). In
contrast to what occurs in normally developing children, there is a progressive
IQ decline in DS, beginning in the first year of life. T ... read full excerpt from Therapies and Rehabilitation in Down Syndrome ebook
