## Abstract Seven families with Xβlinked mental retardation (MR) have been studied clinically and cytogenetically. All affected males in six of the families were found to have a fragile site on Xq in a number of their peripheral lymphocytes. The fragile site was not seen in any of the affected male
Study of X-linked mental retardation (XLMR): Summary of 61 families in the Miami Greenwood study
β Scribed by Lubs, H. A.; Schwartz, C. E.; Stevenson, R. E.; Arena, J. F.
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 79 KB
- Volume
- 64
- Category
- Article
- ISSN
- 0148-7299
No coin nor oath required. For personal study only.
β¦ Synopsis
The initial goal of this study was to localize as many genes as possible that lead to syndromic and non-specific XLMR. More recently, this goal has been redefined to include narrowing these localizations and cloning specific genes. In the last 5 years, 61 families have participated in this study; 34 have a projected or actual lod score greater than 2.0. Restudy of 12 families reported previously has been a particularly productive aspect of this study and has led to clinical redefinition and new or improved localization of most of these syndromes. Five possible new XLMR syndromes have been identified. Five large families with nonspecific XLMR have been regionally localized. Since many XLMR conditions are based on only 1 or 2 family reports, one of the major purposes of this summary is to provide clinical data on the study families so that collaborative projects can be undertaken with other centers that have similar families.
π SIMILAR VOLUMES
The identification of X-linked mental retardation genes (XLMR) represents a challenge of considerable medical importance, given the reported high cumulative frequency of this heterogenous disorder, estimated at approximately 1/600 male births. Whereas pooling families is useful to fine-map genetic l
## Communicated by Andreas Gal The EuroMRX family cohort consists of about 400 families with non-syndromic and 200 families with syndromic X-linked mental retardation (XLMR). After exclusion of Fragile X (Fra X) syndrome, probands from these families were tested for mutations in the coding sequenc
Mental retardation (MR) is a common condition with no general mechanism suggested. Mild MR (70 > IQ > 50) is present in 2-3% of the general population, whereas 0.3% presents severe forms of MR (IQ < 50) . Two different forms of MR could be distinguished: nonsyndromic MR, where affected patients do n
X-linked alpha-thalassemia/mental retardation syndrome (ATR-X) is a syndromic form of X-linked mental retardation. We investigated the X-inactivation status of nine female ATR-X carriers by methylation-specific PCR of the HUMARA gene. Six carriers demonstrated a skewed X-inactivation pattern (>90:10
Three p o p u l a t i o n s of r e t a r d e d i n d i v i d u a l s were s u rveyed and t h e f r e q u e n c y of t h e f r a (X) w a s found t o b e 1 . 9 % i n males and 0.3% i n females. STUDY POPULATIONS W e have completed s u r v e y s of 3 p o p u l a t i o n s of m e n t a l l y r e t a r d