DNA TESTING FOR FRAGILE-X-SYNDROME - IMPLICATIONS FOR PARENTS AND FAMILY

Citation
Ma. Vanrijn et al., DNA TESTING FOR FRAGILE-X-SYNDROME - IMPLICATIONS FOR PARENTS AND FAMILY, Journal of Medical Genetics, 34(11), 1997, pp. 907-911
Citations number
38
Categorie Soggetti
Genetics & Heredity
Journal title
ISSN journal
00222593
Volume
34
Issue
11
Year of publication
1997
Pages
907 - 911
Database
ISI
SICI code
0022-2593(1997)34:11<907:DTFF-I>2.0.ZU;2-O
Abstract
The fragile X syndrome is an X linked, semidominant mental retardation disorder caused by the amplification of a CGG repeat in the 5' UTR of the FIMR1 gene. Nineteen fragile X families in which the mutated FIMR 1 gene segregated were evaluated. The implications of the diagnosis fo r the parents and family were studied through pedigree information, in terviews, and questionnaires. Information about the heredity of fragil e X syndrome was only disseminated by family members to a third (124/3 66) of the relatives with an a priori risk of being a carrier of the f ragile X syndrome. Twenty-six percent (94/366) of the relatives were t ested. Transmission of information among first degree relatives seemed satisfactory but dropped off sharply with increasing distance of the genetic relationship, leaving 66% uninformed. This is particularly dis advantageous in an X linked disease. Of those subjects tested, 42% (39 /94) had a premutation and 18% (17/94) had a full mutation. On average , in each family one new fragile X patient and two new carriers were f ound. When people have the task of transmitting genetic information to their relatives, they usually feel responsible and capable; however, reduced acquaintance and contact with more distant relatives severely reduces the effectiveness of such transfer of information in fragile X families.